Cutis

THE DIAGNOSIS: Neutrophilic Eccrine Hidradenitis

A biopsy from the left preauricular cheek demonstrated dermal neutrophilic inflammation around eccrine coils with focal necrosis (Figure). No notable diffuse dermal neutrophilic infiltrate was present, ruling out Sweet syndrome, and no notable interstitial neutrophilic infiltrate was present, making cellulitis and erysipelas less likely; panculture of tissue also was negative.^1,2 Atypical cells in the deep dermis were positive for CD163 and negative for CD117, CD34, CD123, and myeloperoxidase, consistent with a diagnosis of neutrophilic eccrine hidradenitis (NEH) and reactive histiocytes.³ Treatment with oral prednisone resulted in rapid improvement of symptoms.

Neutrophilic eccrine hidradenitis is a rare reactive neutrophilic dermatosis characterized by eccrine gland involvement. This benign and self-limited condition presents as asymmetric erythematous papules and plaques.² Among 8 granulocytopenic patients with neutrophilic dermatoses, 5 were diagnosed with NEH.⁴ Although first identified in 1982, NEH remains poorly understood.² Initial theories suggested that NEH developed due to cytotoxic substances secreted in sweat glands causing necrosis and neutrophil chemotaxis; however, chemotherapy exposure cannot be linked to every case of NEH. Neutrophilic eccrine hidradenitis can be extremely difficult to differentiate clinically from conditions such as cellulitis and Sweet syndrome.

A patient history can be helpful in identifying triggering factors. Neutrophilic eccrine hidradenitis most commonly is associated with malignant, drug-induced, or infectious triggers, while Sweet syndrome has a broad range of associations including infections, vaccines, inflammatory bowel disease, pregnancy, malignancy, and drug-induced etiologies (Table).¹ On average, NEH presents 10 days after chemotherapy induction, with 70% of cases presenting after the first chemotherapy cycle.⁵ Bacterial cellulitis or erysipelas have an infectious etiology, and patients may report symptoms such as fever, chills, or malaise. Immunosuppressed patients are at greater risk for infection; therefore, clinical signs of infection in a granulocytopenic patient should be addressed urgently.

Physical examination may have limited value in differentiating between these diagnoses, as neutrophilic dermatoses notoriously mimic infection. Cutaneous lesions can appear as pruritic or tender erythematous plaques, papules, or nodules in these conditions, though cellulitis and erysipelas tend to be unilateral and may have associated purulence or inflamed skin lymphatics. Given the potential for misdiagnosis, approaching patients with a broad differential can be helpful. In our patient, the differential diagnosis included Sweet syndrome, NEH, bacterial cellulitis, erysipelas, leukemia cutis, sarcoid, and eosinophilic cellulitis.

Leukemia cutis refers to the infiltration of neoplastic leukocytes in the skin and often occurs in patients with peripheral leukemia, most often acute myeloid leukemia or chronic lymphocytic leukemia. Patients with leukemia cutis often have a worse prognosis, as this finding signifies extramedullary spread of disease.⁶ Clinically, lesions can appear similar to those seen in our patient, though they typically are not symptomatic, can be nodular, tend to exhibit a violaceous hue, and occasionally may be hemorrhagic. Wells syndrome (also known as eosinophilic cellulitis) is an inflammatory dermatosis that presents as painful or pruritic, edematous and erythematous plaques.^7,8 A green hue on resolution is present in some cases and may help clinicians differentiate this disease from mimickers.⁷ Often, eosinophilic cellulitis is misdiagnosed as bacterial cellulitis and treated with antibiotics. The presence of systemic symptoms such as fever or arthralgia is more typical of bacterial cellulitis, erysipelas, eosinophilic cellulitis, or Sweet syndrome than of NEH.¹ Additionally, inflammatory markers (ie, C-reactive protein) and white blood cell counts tend to be elevated in bacterial cellulitis and Sweet syndrome, while leukopenia often is seen in NEH.

Histopathology is crucial in distinguishing these disease etiologies. Neutrophilic eccrine hidradenitis is diagnosed by the characteristic neutrophilic infiltrate and necrosis surrounding eccrine glands and coils. There also may be occasional intraductal abscesses and syringosquamous metaplasia of the sweat glands along with fibrosis of the adjacent dermis. In contrast, histologic sections of Sweet syndrome show numerous mature neutrophils infiltrating the dermis with marked papillary dermal edema. The histopathology of bacterial cellulitis and erysipelas is less specific, but common features include dermal edema, lymphatic dilation, and a diffuse neutrophilic infiltrate surrounding blood vessels. Pathogenic organisms may be seen on histopathology but are not required for the diagnosis of bacterial cellulitis or erysipelas.² Additionally, blood and tissue culture can assist in identification of both the source of infection and the causative organism, but cultures may not always be positive. 

Comparatively, the histopathologic features of eosinophilic cellulitis include dermal edema, eosinophilic infiltration, and flame figures that form when eosinophils degranulate and coat collagen fibers with major basic protein. Flame figures are characteristic but not pathognomonic for eosinophilic cellulitis.⁷ The histopathology of leukemia cutis varies based on the leukemia classification; generally, in acute myeloid leukemia the infiltrate is composed of neoplastic cells in the early stages of development that are positive for myeloid markers such as myeloperoxidase. Atypical and immature granulocytes within the leukocytic infiltrate differentiate this condition from the other diagnoses. Treatment may entail chemotherapy or radiotherapy, and this diagnosis generally carries the worst prognosis of all the conditions in the differential.⁶

Differentiating between these conditions is important in guiding treatment, especially in patients with febrile neutropenia. Unnecessary steroids in immunosuppressed patients can be dangerous, especially if the patient has an infection such as bacterial cellulitis. Furthermore, unwarranted antibiotic use for noninfectious conditions may expose patients to substantial side effects and not improve the condition. Neutrophilic eccrine hidradenitis typically is self-limited and treated symptomatically with systemic corticosteroids and nonsteroidal anti-inflammatory drugs.³ Sweet syndrome often requires a longer course of oral steroids. Leukemia cutis worsens as the leukemia advances, and treatment of the underlying malignancy is the most effective treatment.⁹

Early and accurate recognition of the diagnosis can prevent harmful diagnostic delay, unnecessary antibiotic use, or extended steroid taper in neutropenic patients. Appreciating the differences between these diagnoses can assist clinicians in investigating and tailoring a broad differential to specific patient presentations, which is especially critical when considering common mimickers for life-threatening conditions.

THE DIAGNOSIS: Neutrophilic Eccrine Hidradenitis

A biopsy from the left preauricular cheek demonstrated dermal neutrophilic inflammation around eccrine coils with focal necrosis (Figure). No notable diffuse dermal neutrophilic infiltrate was present, ruling out Sweet syndrome, and no notable interstitial neutrophilic infiltrate was present, making cellulitis and erysipelas less likely; panculture of tissue also was negative.^1,2 Atypical cells in the deep dermis were positive for CD163 and negative for CD117, CD34, CD123, and myeloperoxidase, consistent with a diagnosis of neutrophilic eccrine hidradenitis (NEH) and reactive histiocytes.³ Treatment with oral prednisone resulted in rapid improvement of symptoms.

Neutrophilic eccrine hidradenitis is a rare reactive neutrophilic dermatosis characterized by eccrine gland involvement. This benign and self-limited condition presents as asymmetric erythematous papules and plaques.² Among 8 granulocytopenic patients with neutrophilic dermatoses, 5 were diagnosed with NEH.⁴ Although first identified in 1982, NEH remains poorly understood.² Initial theories suggested that NEH developed due to cytotoxic substances secreted in sweat glands causing necrosis and neutrophil chemotaxis; however, chemotherapy exposure cannot be linked to every case of NEH. Neutrophilic eccrine hidradenitis can be extremely difficult to differentiate clinically from conditions such as cellulitis and Sweet syndrome.

A patient history can be helpful in identifying triggering factors. Neutrophilic eccrine hidradenitis most commonly is associated with malignant, drug-induced, or infectious triggers, while Sweet syndrome has a broad range of associations including infections, vaccines, inflammatory bowel disease, pregnancy, malignancy, and drug-induced etiologies (Table).¹ On average, NEH presents 10 days after chemotherapy induction, with 70% of cases presenting after the first chemotherapy cycle.⁵ Bacterial cellulitis or erysipelas have an infectious etiology, and patients may report symptoms such as fever, chills, or malaise. Immunosuppressed patients are at greater risk for infection; therefore, clinical signs of infection in a granulocytopenic patient should be addressed urgently.

Physical examination may have limited value in differentiating between these diagnoses, as neutrophilic dermatoses notoriously mimic infection. Cutaneous lesions can appear as pruritic or tender erythematous plaques, papules, or nodules in these conditions, though cellulitis and erysipelas tend to be unilateral and may have associated purulence or inflamed skin lymphatics. Given the potential for misdiagnosis, approaching patients with a broad differential can be helpful. In our patient, the differential diagnosis included Sweet syndrome, NEH, bacterial cellulitis, erysipelas, leukemia cutis, sarcoid, and eosinophilic cellulitis.

Leukemia cutis refers to the infiltration of neoplastic leukocytes in the skin and often occurs in patients with peripheral leukemia, most often acute myeloid leukemia or chronic lymphocytic leukemia. Patients with leukemia cutis often have a worse prognosis, as this finding signifies extramedullary spread of disease.⁶ Clinically, lesions can appear similar to those seen in our patient, though they typically are not symptomatic, can be nodular, tend to exhibit a violaceous hue, and occasionally may be hemorrhagic. Wells syndrome (also known as eosinophilic cellulitis) is an inflammatory dermatosis that presents as painful or pruritic, edematous and erythematous plaques.^7,8 A green hue on resolution is present in some cases and may help clinicians differentiate this disease from mimickers.⁷ Often, eosinophilic cellulitis is misdiagnosed as bacterial cellulitis and treated with antibiotics. The presence of systemic symptoms such as fever or arthralgia is more typical of bacterial cellulitis, erysipelas, eosinophilic cellulitis, or Sweet syndrome than of NEH.¹ Additionally, inflammatory markers (ie, C-reactive protein) and white blood cell counts tend to be elevated in bacterial cellulitis and Sweet syndrome, while leukopenia often is seen in NEH.

Histopathology is crucial in distinguishing these disease etiologies. Neutrophilic eccrine hidradenitis is diagnosed by the characteristic neutrophilic infiltrate and necrosis surrounding eccrine glands and coils. There also may be occasional intraductal abscesses and syringosquamous metaplasia of the sweat glands along with fibrosis of the adjacent dermis. In contrast, histologic sections of Sweet syndrome show numerous mature neutrophils infiltrating the dermis with marked papillary dermal edema. The histopathology of bacterial cellulitis and erysipelas is less specific, but common features include dermal edema, lymphatic dilation, and a diffuse neutrophilic infiltrate surrounding blood vessels. Pathogenic organisms may be seen on histopathology but are not required for the diagnosis of bacterial cellulitis or erysipelas.² Additionally, blood and tissue culture can assist in identification of both the source of infection and the causative organism, but cultures may not always be positive. 

Comparatively, the histopathologic features of eosinophilic cellulitis include dermal edema, eosinophilic infiltration, and flame figures that form when eosinophils degranulate and coat collagen fibers with major basic protein. Flame figures are characteristic but not pathognomonic for eosinophilic cellulitis.⁷ The histopathology of leukemia cutis varies based on the leukemia classification; generally, in acute myeloid leukemia the infiltrate is composed of neoplastic cells in the early stages of development that are positive for myeloid markers such as myeloperoxidase. Atypical and immature granulocytes within the leukocytic infiltrate differentiate this condition from the other diagnoses. Treatment may entail chemotherapy or radiotherapy, and this diagnosis generally carries the worst prognosis of all the conditions in the differential.⁶

Differentiating between these conditions is important in guiding treatment, especially in patients with febrile neutropenia. Unnecessary steroids in immunosuppressed patients can be dangerous, especially if the patient has an infection such as bacterial cellulitis. Furthermore, unwarranted antibiotic use for noninfectious conditions may expose patients to substantial side effects and not improve the condition. Neutrophilic eccrine hidradenitis typically is self-limited and treated symptomatically with systemic corticosteroids and nonsteroidal anti-inflammatory drugs.³ Sweet syndrome often requires a longer course of oral steroids. Leukemia cutis worsens as the leukemia advances, and treatment of the underlying malignancy is the most effective treatment.⁹

Early and accurate recognition of the diagnosis can prevent harmful diagnostic delay, unnecessary antibiotic use, or extended steroid taper in neutropenic patients. Appreciating the differences between these diagnoses can assist clinicians in investigating and tailoring a broad differential to specific patient presentations, which is especially critical when considering common mimickers for life-threatening conditions.

THE DIAGNOSIS: Neutrophilic Eccrine Hidradenitis

A biopsy from the left preauricular cheek demonstrated dermal neutrophilic inflammation around eccrine coils with focal necrosis (Figure). No notable diffuse dermal neutrophilic infiltrate was present, ruling out Sweet syndrome, and no notable interstitial neutrophilic infiltrate was present, making cellulitis and erysipelas less likely; panculture of tissue also was negative.^1,2 Atypical cells in the deep dermis were positive for CD163 and negative for CD117, CD34, CD123, and myeloperoxidase, consistent with a diagnosis of neutrophilic eccrine hidradenitis (NEH) and reactive histiocytes.³ Treatment with oral prednisone resulted in rapid improvement of symptoms.

Neutrophilic eccrine hidradenitis is a rare reactive neutrophilic dermatosis characterized by eccrine gland involvement. This benign and self-limited condition presents as asymmetric erythematous papules and plaques.² Among 8 granulocytopenic patients with neutrophilic dermatoses, 5 were diagnosed with NEH.⁴ Although first identified in 1982, NEH remains poorly understood.² Initial theories suggested that NEH developed due to cytotoxic substances secreted in sweat glands causing necrosis and neutrophil chemotaxis; however, chemotherapy exposure cannot be linked to every case of NEH. Neutrophilic eccrine hidradenitis can be extremely difficult to differentiate clinically from conditions such as cellulitis and Sweet syndrome.

A patient history can be helpful in identifying triggering factors. Neutrophilic eccrine hidradenitis most commonly is associated with malignant, drug-induced, or infectious triggers, while Sweet syndrome has a broad range of associations including infections, vaccines, inflammatory bowel disease, pregnancy, malignancy, and drug-induced etiologies (Table).¹ On average, NEH presents 10 days after chemotherapy induction, with 70% of cases presenting after the first chemotherapy cycle.⁵ Bacterial cellulitis or erysipelas have an infectious etiology, and patients may report symptoms such as fever, chills, or malaise. Immunosuppressed patients are at greater risk for infection; therefore, clinical signs of infection in a granulocytopenic patient should be addressed urgently.

Physical examination may have limited value in differentiating between these diagnoses, as neutrophilic dermatoses notoriously mimic infection. Cutaneous lesions can appear as pruritic or tender erythematous plaques, papules, or nodules in these conditions, though cellulitis and erysipelas tend to be unilateral and may have associated purulence or inflamed skin lymphatics. Given the potential for misdiagnosis, approaching patients with a broad differential can be helpful. In our patient, the differential diagnosis included Sweet syndrome, NEH, bacterial cellulitis, erysipelas, leukemia cutis, sarcoid, and eosinophilic cellulitis.

Leukemia cutis refers to the infiltration of neoplastic leukocytes in the skin and often occurs in patients with peripheral leukemia, most often acute myeloid leukemia or chronic lymphocytic leukemia. Patients with leukemia cutis often have a worse prognosis, as this finding signifies extramedullary spread of disease.⁶ Clinically, lesions can appear similar to those seen in our patient, though they typically are not symptomatic, can be nodular, tend to exhibit a violaceous hue, and occasionally may be hemorrhagic. Wells syndrome (also known as eosinophilic cellulitis) is an inflammatory dermatosis that presents as painful or pruritic, edematous and erythematous plaques.^7,8 A green hue on resolution is present in some cases and may help clinicians differentiate this disease from mimickers.⁷ Often, eosinophilic cellulitis is misdiagnosed as bacterial cellulitis and treated with antibiotics. The presence of systemic symptoms such as fever or arthralgia is more typical of bacterial cellulitis, erysipelas, eosinophilic cellulitis, or Sweet syndrome than of NEH.¹ Additionally, inflammatory markers (ie, C-reactive protein) and white blood cell counts tend to be elevated in bacterial cellulitis and Sweet syndrome, while leukopenia often is seen in NEH.

Histopathology is crucial in distinguishing these disease etiologies. Neutrophilic eccrine hidradenitis is diagnosed by the characteristic neutrophilic infiltrate and necrosis surrounding eccrine glands and coils. There also may be occasional intraductal abscesses and syringosquamous metaplasia of the sweat glands along with fibrosis of the adjacent dermis. In contrast, histologic sections of Sweet syndrome show numerous mature neutrophils infiltrating the dermis with marked papillary dermal edema. The histopathology of bacterial cellulitis and erysipelas is less specific, but common features include dermal edema, lymphatic dilation, and a diffuse neutrophilic infiltrate surrounding blood vessels. Pathogenic organisms may be seen on histopathology but are not required for the diagnosis of bacterial cellulitis or erysipelas.² Additionally, blood and tissue culture can assist in identification of both the source of infection and the causative organism, but cultures may not always be positive. 

Comparatively, the histopathologic features of eosinophilic cellulitis include dermal edema, eosinophilic infiltration, and flame figures that form when eosinophils degranulate and coat collagen fibers with major basic protein. Flame figures are characteristic but not pathognomonic for eosinophilic cellulitis.⁷ The histopathology of leukemia cutis varies based on the leukemia classification; generally, in acute myeloid leukemia the infiltrate is composed of neoplastic cells in the early stages of development that are positive for myeloid markers such as myeloperoxidase. Atypical and immature granulocytes within the leukocytic infiltrate differentiate this condition from the other diagnoses. Treatment may entail chemotherapy or radiotherapy, and this diagnosis generally carries the worst prognosis of all the conditions in the differential.⁶

Differentiating between these conditions is important in guiding treatment, especially in patients with febrile neutropenia. Unnecessary steroids in immunosuppressed patients can be dangerous, especially if the patient has an infection such as bacterial cellulitis. Furthermore, unwarranted antibiotic use for noninfectious conditions may expose patients to substantial side effects and not improve the condition. Neutrophilic eccrine hidradenitis typically is self-limited and treated symptomatically with systemic corticosteroids and nonsteroidal anti-inflammatory drugs.³ Sweet syndrome often requires a longer course of oral steroids. Leukemia cutis worsens as the leukemia advances, and treatment of the underlying malignancy is the most effective treatment.⁹

Early and accurate recognition of the diagnosis can prevent harmful diagnostic delay, unnecessary antibiotic use, or extended steroid taper in neutropenic patients. Appreciating the differences between these diagnoses can assist clinicians in investigating and tailoring a broad differential to specific patient presentations, which is especially critical when considering common mimickers for life-threatening conditions.

Pyoderma gangrenosum (PG), acne, and hidradenitis suppurativa (HS)(PASH) syndrome is a recently identified disease process within the spectrum of autoinflammatory diseases (AIDs), which are distinct from autoimmune, infectious, and allergic syndromes and are gaining increasing interest given their complex pathophysiology and therapeutic resistance.¹ Autoinflammatory diseases are defined by a dysregulation of the innate immune system in the absence of typical autoimmune features, including autoantibodies and antigen-specific T lymphocytes.² Mutations affecting proteins of the inflammasome or proteins involved in regulating inflammasome function have been associated with these AIDs.²

Many AIDs have cutaneous involvement, as seen in PASH syndrome. Pyoderma gangrenosum is a neutrophilic dermatosis presenting as skin ulcers with undermined, erythematous, violaceous borders. It can be isolated, syndromic, or associated with inflammatory conditions (eg, inflammatory bowel disease, rheumatologic disorders, hematologic disorders).¹ Acne vulgaris develops because of chronic obstruction of hair follicles as a result of disordered keratinization and abnormal sebaceous stem cell differentiation.²Propionibacterium acnes can reside and replicate within the biofilm community of the hair follicle and activate the inflammasome.^2,3 Hidradenitis suppurativa, a chronic relapsing neutrophilic dermatosis, is a debilitating inflammatory disease of the hair follicles involving apocrine gland–bearing skin (ie, the axillary, inguinal, and anogenital regions).² Onset often occurs between the ages of 20 and 40 years, with a 3-fold higher incidence in women compared to men.³ Patients experience painful, deep-seated nodules that drain into sinus tracts and abscesses. The condition can be isolated or associated with inflammatory conditions, such as inflammatory bowel disease.⁴

PASH syndrome has been described as a polygenic autoinflammatory condition that most commonly presents in young adults, with onset of acne beginning years prior to other manifestations. A study analyzing 5 patients with PASH syndrome reported an average age of 32.2 years at diagnosis with a disease duration of 3 to 7 years.⁵ Pathophysiology of this condition is not well understood, with many hypotheses calling upon dysregulation of the innate immune system, a commonality this syndrome may share with other AIDs. Given its poorly understood pathophysiology, treating PASH syndrome can be especially difficult. We report a novel case of disease remission lasting more than 4 years using adalimumab and cyclosporine. We also discuss prior treatment successes and hypotheses regarding etiologic factors in PASH syndrome.

Case Report

A 36-year-old woman presented for evaluation of open draining ulcerations on the back of 18 months’ duration. She had a 16-year history of scarring cystic acne of the face and HS of the groin. The patient’s family history was remarkable for severe cystic acne in her brother and son as well as HS in her mother and another brother. Her treatment history included isotretinoin, doxycycline, and topical steroids.

Physical examination revealed 2 ulcerations with violaceous borders involving the left upper back (greatest diameter, 5×7 cm)(Figure 1). Evidence of papular and cystic acne with residual scarring was noted on the cheeks. Scarring from HS was noted in the axillae and right groin. A biopsy from the edge of an ulceration on the back demonstrated epidermal spongiosis with acute and chronic inflammation and fibrosis (Figure 2). The clinicopathologic findings were most consistent with PG, and the patient was diagnosed with PASH syndrome, given the constellation of cutaneous lesions.

After treatment with topical and systemic antibiotics for acne and HS for more than 1 year failed, the patient was started on adalimumab. The initial dose was 160 mg subcutaneously, then 80 mg 2 weeks later, then 40 mg weekly thereafter. Doxycycline was continued for treatment of the acne and HS. After 6 weeks of adalimumab, the PG worsened and prednisone was added. She developed tender furuncles on the back, and cultures grew Pseudomonas aeruginosa and methicillin-sensitive Staphylococcus aureus that responded to ciprofloxacin and cephalexin.

Due to progression of PG on adalimumab, switching to an infliximab infusion or anakinra was considered, but these options were not covered by the patient’s health insurance. Three months after the initial presentation, the patient was started on cyclosporine 100 mg 3 times daily (5 mg/kg/d) while adalimumab was continued; the ulcers started to improve within 2.5 weeks. After 3 months (Figure 3), the cyclosporine was reduced to 100 mg twice daily, and adalimumab was continued. She had a slight flare of PG after 8 months of treatment when adalimumab was unavailable to her for 2 months. After 8 months on cyclosporine, the dosage was tapered to 100 mg/d and then completely discontinued after 12 months.

The patient has continued on adalimumab 40 mg weekly with excellent control of the PG (Figure 4), although she did have one HS flare in the left axilla 11 months after the initial treatment. The patient’s cystic acne has intermittently flared and has been managed with spironolactone 100 mg/d for 3 years. After 4 years of management, the patient’s PG and HS remain well controlled on adalimumab.

Comment

Our case represents a major step in refining long-term treatment approaches for PASH syndrome due to the 4-year remission. Prior cases have reported use of anakinra, anakinra-cyclosporine combination, prednisone, azathioprine, topical tacrolimus, etanercept, and dapsone without sustainable success.^1-6 The case studies discussed below have achieved remission via alternative drug combinations.

Staub et al⁴ found greatest success with a combination of infliximab, dapsone, and cyclosporine, and their patient had been in remission for 20 months at time of publication. Their hypothesis proposed that multiple inflammatory signaling pathways are involved in PASH syndrome, and this is why combination therapy is required for remission.⁴ In 2018, Lamiaux et al⁷ demonstrated successful treatment with rifampicin and clindamycin. Their patient had been in remission for 22 months at the time of publication—this time frame included 12 months of combination therapy and 10 months without medication. The authors hypothesized that, because of the autoinflammatory nature of these antibiotics, this pharmacologic combination could eradicate pathogenic bacteria from host microbiota while also inhibiting neutrophil function and synthesis of chemokines and cytokines.⁷

More recently, reports have been published regarding the success of tildrakizumab, an IL-23 antagonist, and ixekizumab, an IL-17 antagonist, in the treatment of PASH syndrome.^6,8 Ixekizumab was used in combination with doxycycline, and remission was achieved in 12 months.⁸ However, tildrakizumab was used alone and achieved greater than 75% improvement in disease manifestations within 2 months.

Marzano et al⁵ conducted protein arrays and enzyme-linked immunosorbent assay to analyze the expression of cytokine, chemokine, and effector molecule profiles in PASH syndrome. It was determined that serum analysis displayed a normal cytokine/chemokine profile, with the only abnormalities being anemia and elevated C-reactive protein. There were no statistically significant differences in serum levels of IL-1β, tumor necrosis factor (TNF) α, or IL-17 between PASH syndrome and healthy controls. However, cutaneous analysis revealed extensive cytokine and chemokine hyperactivity for IL-1β and IL-1β receptor; TNF-α; C-X-C motif ligands 1, 2, and 3; C-X-C motif ligand 16; regulated on activation, normal T cell expressed and secreted; IL-17 and IL-17R; Fas/Fas ligand; and CD40/CD40L. This cutaneous profile of elevated cytokines and chemokines mirrors that of nonsyndromic PG and many other AIDs. These results demonstrate that the inflammation in PASH syndrome is localized mainly to the skin and further support the hypothesis that possibilities for alternative treatment options are diverse.⁵

Ead et al³ presented a unique perspective focusing on cutaneous biofilm involvement in PASH syndrome. Microbes within these biofilms induce the migration and proliferation of inflammatory cells that consume factors normally utilized for tissue catabolism. These organisms deplete necessary biochemical cofactors used during healing. This lack of nutrients needed for healing not only slows the process but also promotes favorable conditions for the growth of anerobic species. In conjunction, biofilm formation restricts bacterial access to oxygen and nutrients, thus decreasing the bacterial metabolic rate and preventing the effects of antibiotic therapy. These features of biofilm communities contribute to inflammation and possibly the troubling resistance to many therapeutic options for PASH syndrome.

Each component of PASH syndrome has been associated with biofilm formation. As previously described, PG manifests in the skin as painful ulcerations, often with slough. This slough is hypothesized to be a consequence of increased vascular permeability and exudative byproducts that accompany the inflammatory nature of biofilms.³ Acne vulgaris has well-described associations with P acnes. Ead et al³ described P acnes as a component of the biofilm community within the microcomedone of hair follicles. This biofilm allows for antibiotic resistance occasionally seen in the treatment of acne and is potentially the pathogenic factor that both impedes healing and enhances the inflammatory state. Hidradenitis suppurativa has been associated with biofilm formation.³

In further pursuit of PASH syndrome pathophysiology, many experts have sought to uncover the relationship between PASH syndrome and the previously described pyogenic arthritis, PG, and acne (PAPA) syndrome, another entity within the AIDs spectrum (Table). This condition was first recognized in 1997 in a 3-generation family with 10 affected members.¹ It is characterized by PG and acne, similar to PASH; however, PAPA syndrome includes PG arthritis and lacks HS. Pyogenic arthritis manifests as recurrent aseptic inflammation of the joints, mainly the elbows, knees, and ankles. Pyogenic arthritis commonly is the presenting symptom of PAPA syndrome, with onset in childhood.² As patients age, the arthritic symptoms decrease, and skin manifestations become more prominent.

PAPA syndrome has autosomal-dominant inheritance with mutations on chromosome 15 in the proline-serine-threonine phosphatase interacting protein 1 (PSTPIP1) gene.¹ This mutation induces hyperphosphorylation of PSTPIP1, allowing for increased binding affinity to pyrin. Both PSTPIP1 and pyrin are co-expressed as parts of the NLRP3 inflammasome in granulocytes and monocytes.¹ As a result, pyrin is more highly bound and loses its inhibitory effect on the NLRP3 inflammasome pathway. This lack of inhibition allows for uninhibited cleavage of pro–IL-1β to active IL-1β by the inflammasome.¹

Elevated concentrations of IL-1β in patients with PAPA syndrome result in a dysregulation of the innate immune system. IL-1β induces the release of proinflammatory cytokines, namely TNF-α; interferon γ; IL-8; and regulated on activation, normal T cell expressed and secreted (RANTES), all of which activate neutrophils and induce neutrophilic inflammation.² IL-1β not only initiates this entire cascade but also acts as an antiapoptotic signal for neutrophils.² When IL-1β reaches a critical threshold, it induces enough inflammation to cause severe tissue damage, thus causing joint and cutaneous disease in PAPA syndrome. IL-1 inhibitors (anakinra) or TNF-α inhibitors (etanercept, adalimumab, infliximab) have been used many times to successfully treat PAPA syndrome, with TNF-α inhibitors providing the most consistent results.

Another AIDs entity with similarities to both PAPA syndrome and PASH syndrome is pyogenic arthritis, PG, acne, and HS (PA-PASH) syndrome. First identified in 2012 by Bruzzese,⁹ genetic analyses revealed a p.E277D missense mutation in PSTPIP1 in PA-PASH syndrome. Research has suggested that the key molecular feature is neutrophil activation by T_H17 cells and the TNF-α axis.⁹ This syndrome has not been further characterized, and little is known regarding adequate treatment for PA-PASH syndrome.

Although it is similar in phenotype to aspects of PAPA and PA-PASH syndromes, PASH syndrome has distinct genotypic and immunologic abnormalities. Genetic analysis of this condition has shown an increased number of CCTG repeats in proximity to the PSTPIP1 promoter. It is hypothesized that these additional repeats predispose patients to neutrophilic inflammation in a similar manner to a condition described in France, termed aseptic abscess syndrome.^1,5 Other mutations have been identified, including those in IL-1N, PSMB8, MEFV, NOD2, NCSTN, and more.^2,7 However, it has been determined that the majority of these variants have already been filed in the Single Nucleotide Polymorphism Database or in the Registry of Hereditary Auto-inflammatory Disorders Mutations.² The question remains regarding the origin of inflammation seen in PASH syndrome; the potential role of biofilms; and the relationship between PASH, PAPA, and PA-PASH syndromes. Much work remains to be done in refining therapeutic options for PASH syndrome. Continued biochemical research is necessary, as well as collaboration among dermatologists worldwide who find success in treating this condition.

Conclusion

There are genotypic and phenotypic similarities between PASH, PAPA, and PA-PASH syndromes, with various mutations within or near the PSTPIP1 gene; however, their genetic discrepancies seem to play a major role in the pathophysiology of each syndrome. Much work remains to be done in PA-PASH syndrome, which has not yet been well described. Meanwhile, PAPA syndrome has been well characterized with mutations affecting proteins of the NLRP3 inflammasome, resulting in elevated IL-1β and excess neutrophilic inflammation. In PASH syndrome, the importance of increased repeats near the PSTPIP1 promoter is yet to be elucidated. It has been shown that these abnormalities predispose individuals to neutrophilic inflammation, but the mechanism by which they do so is unknown. In addition, consideration of biofilms and their predisposition to inflammation within the pathophysiology of PASH syndrome is a possibility that must be considered when discussing therapeutic options. Based on our case study and previous successes in treating PASH syndrome, it is clear that a multidrug approach is necessary for remission. It is likely that the etiology of PASH syndrome is multifaceted and involves hyperactivity in multiple arms of the innate immune system.

Patients with PASH syndrome have severely impaired quality of life and often experience social withdrawal due to the disfiguring sequelae and limited treatment options available. To improve patient outcomes, it is essential for physicians and scientists to report on successful treatment strategies and advances in immunologic understanding. Improved understanding of PASH syndrome calls for further genetic exploration into the role of additional genomic repeats and how these affect the PSTPIP1 gene and inflammasome activity. As medical advances improve understanding of the pathophysiology of this disease entity, it will likely become clear which mechanisms are most important in disease progression and how clinicians can best optimize treatment.

Pyoderma gangrenosum (PG), acne, and hidradenitis suppurativa (HS)(PASH) syndrome is a recently identified disease process within the spectrum of autoinflammatory diseases (AIDs), which are distinct from autoimmune, infectious, and allergic syndromes and are gaining increasing interest given their complex pathophysiology and therapeutic resistance.¹ Autoinflammatory diseases are defined by a dysregulation of the innate immune system in the absence of typical autoimmune features, including autoantibodies and antigen-specific T lymphocytes.² Mutations affecting proteins of the inflammasome or proteins involved in regulating inflammasome function have been associated with these AIDs.²

Many AIDs have cutaneous involvement, as seen in PASH syndrome. Pyoderma gangrenosum is a neutrophilic dermatosis presenting as skin ulcers with undermined, erythematous, violaceous borders. It can be isolated, syndromic, or associated with inflammatory conditions (eg, inflammatory bowel disease, rheumatologic disorders, hematologic disorders).¹ Acne vulgaris develops because of chronic obstruction of hair follicles as a result of disordered keratinization and abnormal sebaceous stem cell differentiation.²Propionibacterium acnes can reside and replicate within the biofilm community of the hair follicle and activate the inflammasome.^2,3 Hidradenitis suppurativa, a chronic relapsing neutrophilic dermatosis, is a debilitating inflammatory disease of the hair follicles involving apocrine gland–bearing skin (ie, the axillary, inguinal, and anogenital regions).² Onset often occurs between the ages of 20 and 40 years, with a 3-fold higher incidence in women compared to men.³ Patients experience painful, deep-seated nodules that drain into sinus tracts and abscesses. The condition can be isolated or associated with inflammatory conditions, such as inflammatory bowel disease.⁴

PASH syndrome has been described as a polygenic autoinflammatory condition that most commonly presents in young adults, with onset of acne beginning years prior to other manifestations. A study analyzing 5 patients with PASH syndrome reported an average age of 32.2 years at diagnosis with a disease duration of 3 to 7 years.⁵ Pathophysiology of this condition is not well understood, with many hypotheses calling upon dysregulation of the innate immune system, a commonality this syndrome may share with other AIDs. Given its poorly understood pathophysiology, treating PASH syndrome can be especially difficult. We report a novel case of disease remission lasting more than 4 years using adalimumab and cyclosporine. We also discuss prior treatment successes and hypotheses regarding etiologic factors in PASH syndrome.

Case Report

A 36-year-old woman presented for evaluation of open draining ulcerations on the back of 18 months’ duration. She had a 16-year history of scarring cystic acne of the face and HS of the groin. The patient’s family history was remarkable for severe cystic acne in her brother and son as well as HS in her mother and another brother. Her treatment history included isotretinoin, doxycycline, and topical steroids.

Physical examination revealed 2 ulcerations with violaceous borders involving the left upper back (greatest diameter, 5×7 cm)(Figure 1). Evidence of papular and cystic acne with residual scarring was noted on the cheeks. Scarring from HS was noted in the axillae and right groin. A biopsy from the edge of an ulceration on the back demonstrated epidermal spongiosis with acute and chronic inflammation and fibrosis (Figure 2). The clinicopathologic findings were most consistent with PG, and the patient was diagnosed with PASH syndrome, given the constellation of cutaneous lesions.

After treatment with topical and systemic antibiotics for acne and HS for more than 1 year failed, the patient was started on adalimumab. The initial dose was 160 mg subcutaneously, then 80 mg 2 weeks later, then 40 mg weekly thereafter. Doxycycline was continued for treatment of the acne and HS. After 6 weeks of adalimumab, the PG worsened and prednisone was added. She developed tender furuncles on the back, and cultures grew Pseudomonas aeruginosa and methicillin-sensitive Staphylococcus aureus that responded to ciprofloxacin and cephalexin.

Due to progression of PG on adalimumab, switching to an infliximab infusion or anakinra was considered, but these options were not covered by the patient’s health insurance. Three months after the initial presentation, the patient was started on cyclosporine 100 mg 3 times daily (5 mg/kg/d) while adalimumab was continued; the ulcers started to improve within 2.5 weeks. After 3 months (Figure 3), the cyclosporine was reduced to 100 mg twice daily, and adalimumab was continued. She had a slight flare of PG after 8 months of treatment when adalimumab was unavailable to her for 2 months. After 8 months on cyclosporine, the dosage was tapered to 100 mg/d and then completely discontinued after 12 months.

The patient has continued on adalimumab 40 mg weekly with excellent control of the PG (Figure 4), although she did have one HS flare in the left axilla 11 months after the initial treatment. The patient’s cystic acne has intermittently flared and has been managed with spironolactone 100 mg/d for 3 years. After 4 years of management, the patient’s PG and HS remain well controlled on adalimumab.

Comment

Our case represents a major step in refining long-term treatment approaches for PASH syndrome due to the 4-year remission. Prior cases have reported use of anakinra, anakinra-cyclosporine combination, prednisone, azathioprine, topical tacrolimus, etanercept, and dapsone without sustainable success.^1-6 The case studies discussed below have achieved remission via alternative drug combinations.

Staub et al⁴ found greatest success with a combination of infliximab, dapsone, and cyclosporine, and their patient had been in remission for 20 months at time of publication. Their hypothesis proposed that multiple inflammatory signaling pathways are involved in PASH syndrome, and this is why combination therapy is required for remission.⁴ In 2018, Lamiaux et al⁷ demonstrated successful treatment with rifampicin and clindamycin. Their patient had been in remission for 22 months at the time of publication—this time frame included 12 months of combination therapy and 10 months without medication. The authors hypothesized that, because of the autoinflammatory nature of these antibiotics, this pharmacologic combination could eradicate pathogenic bacteria from host microbiota while also inhibiting neutrophil function and synthesis of chemokines and cytokines.⁷

More recently, reports have been published regarding the success of tildrakizumab, an IL-23 antagonist, and ixekizumab, an IL-17 antagonist, in the treatment of PASH syndrome.^6,8 Ixekizumab was used in combination with doxycycline, and remission was achieved in 12 months.⁸ However, tildrakizumab was used alone and achieved greater than 75% improvement in disease manifestations within 2 months.

Marzano et al⁵ conducted protein arrays and enzyme-linked immunosorbent assay to analyze the expression of cytokine, chemokine, and effector molecule profiles in PASH syndrome. It was determined that serum analysis displayed a normal cytokine/chemokine profile, with the only abnormalities being anemia and elevated C-reactive protein. There were no statistically significant differences in serum levels of IL-1β, tumor necrosis factor (TNF) α, or IL-17 between PASH syndrome and healthy controls. However, cutaneous analysis revealed extensive cytokine and chemokine hyperactivity for IL-1β and IL-1β receptor; TNF-α; C-X-C motif ligands 1, 2, and 3; C-X-C motif ligand 16; regulated on activation, normal T cell expressed and secreted; IL-17 and IL-17R; Fas/Fas ligand; and CD40/CD40L. This cutaneous profile of elevated cytokines and chemokines mirrors that of nonsyndromic PG and many other AIDs. These results demonstrate that the inflammation in PASH syndrome is localized mainly to the skin and further support the hypothesis that possibilities for alternative treatment options are diverse.⁵

Ead et al³ presented a unique perspective focusing on cutaneous biofilm involvement in PASH syndrome. Microbes within these biofilms induce the migration and proliferation of inflammatory cells that consume factors normally utilized for tissue catabolism. These organisms deplete necessary biochemical cofactors used during healing. This lack of nutrients needed for healing not only slows the process but also promotes favorable conditions for the growth of anerobic species. In conjunction, biofilm formation restricts bacterial access to oxygen and nutrients, thus decreasing the bacterial metabolic rate and preventing the effects of antibiotic therapy. These features of biofilm communities contribute to inflammation and possibly the troubling resistance to many therapeutic options for PASH syndrome.

Each component of PASH syndrome has been associated with biofilm formation. As previously described, PG manifests in the skin as painful ulcerations, often with slough. This slough is hypothesized to be a consequence of increased vascular permeability and exudative byproducts that accompany the inflammatory nature of biofilms.³ Acne vulgaris has well-described associations with P acnes. Ead et al³ described P acnes as a component of the biofilm community within the microcomedone of hair follicles. This biofilm allows for antibiotic resistance occasionally seen in the treatment of acne and is potentially the pathogenic factor that both impedes healing and enhances the inflammatory state. Hidradenitis suppurativa has been associated with biofilm formation.³

In further pursuit of PASH syndrome pathophysiology, many experts have sought to uncover the relationship between PASH syndrome and the previously described pyogenic arthritis, PG, and acne (PAPA) syndrome, another entity within the AIDs spectrum (Table). This condition was first recognized in 1997 in a 3-generation family with 10 affected members.¹ It is characterized by PG and acne, similar to PASH; however, PAPA syndrome includes PG arthritis and lacks HS. Pyogenic arthritis manifests as recurrent aseptic inflammation of the joints, mainly the elbows, knees, and ankles. Pyogenic arthritis commonly is the presenting symptom of PAPA syndrome, with onset in childhood.² As patients age, the arthritic symptoms decrease, and skin manifestations become more prominent.

PAPA syndrome has autosomal-dominant inheritance with mutations on chromosome 15 in the proline-serine-threonine phosphatase interacting protein 1 (PSTPIP1) gene.¹ This mutation induces hyperphosphorylation of PSTPIP1, allowing for increased binding affinity to pyrin. Both PSTPIP1 and pyrin are co-expressed as parts of the NLRP3 inflammasome in granulocytes and monocytes.¹ As a result, pyrin is more highly bound and loses its inhibitory effect on the NLRP3 inflammasome pathway. This lack of inhibition allows for uninhibited cleavage of pro–IL-1β to active IL-1β by the inflammasome.¹

Elevated concentrations of IL-1β in patients with PAPA syndrome result in a dysregulation of the innate immune system. IL-1β induces the release of proinflammatory cytokines, namely TNF-α; interferon γ; IL-8; and regulated on activation, normal T cell expressed and secreted (RANTES), all of which activate neutrophils and induce neutrophilic inflammation.² IL-1β not only initiates this entire cascade but also acts as an antiapoptotic signal for neutrophils.² When IL-1β reaches a critical threshold, it induces enough inflammation to cause severe tissue damage, thus causing joint and cutaneous disease in PAPA syndrome. IL-1 inhibitors (anakinra) or TNF-α inhibitors (etanercept, adalimumab, infliximab) have been used many times to successfully treat PAPA syndrome, with TNF-α inhibitors providing the most consistent results.

Another AIDs entity with similarities to both PAPA syndrome and PASH syndrome is pyogenic arthritis, PG, acne, and HS (PA-PASH) syndrome. First identified in 2012 by Bruzzese,⁹ genetic analyses revealed a p.E277D missense mutation in PSTPIP1 in PA-PASH syndrome. Research has suggested that the key molecular feature is neutrophil activation by T_H17 cells and the TNF-α axis.⁹ This syndrome has not been further characterized, and little is known regarding adequate treatment for PA-PASH syndrome.

Although it is similar in phenotype to aspects of PAPA and PA-PASH syndromes, PASH syndrome has distinct genotypic and immunologic abnormalities. Genetic analysis of this condition has shown an increased number of CCTG repeats in proximity to the PSTPIP1 promoter. It is hypothesized that these additional repeats predispose patients to neutrophilic inflammation in a similar manner to a condition described in France, termed aseptic abscess syndrome.^1,5 Other mutations have been identified, including those in IL-1N, PSMB8, MEFV, NOD2, NCSTN, and more.^2,7 However, it has been determined that the majority of these variants have already been filed in the Single Nucleotide Polymorphism Database or in the Registry of Hereditary Auto-inflammatory Disorders Mutations.² The question remains regarding the origin of inflammation seen in PASH syndrome; the potential role of biofilms; and the relationship between PASH, PAPA, and PA-PASH syndromes. Much work remains to be done in refining therapeutic options for PASH syndrome. Continued biochemical research is necessary, as well as collaboration among dermatologists worldwide who find success in treating this condition.

Conclusion

There are genotypic and phenotypic similarities between PASH, PAPA, and PA-PASH syndromes, with various mutations within or near the PSTPIP1 gene; however, their genetic discrepancies seem to play a major role in the pathophysiology of each syndrome. Much work remains to be done in PA-PASH syndrome, which has not yet been well described. Meanwhile, PAPA syndrome has been well characterized with mutations affecting proteins of the NLRP3 inflammasome, resulting in elevated IL-1β and excess neutrophilic inflammation. In PASH syndrome, the importance of increased repeats near the PSTPIP1 promoter is yet to be elucidated. It has been shown that these abnormalities predispose individuals to neutrophilic inflammation, but the mechanism by which they do so is unknown. In addition, consideration of biofilms and their predisposition to inflammation within the pathophysiology of PASH syndrome is a possibility that must be considered when discussing therapeutic options. Based on our case study and previous successes in treating PASH syndrome, it is clear that a multidrug approach is necessary for remission. It is likely that the etiology of PASH syndrome is multifaceted and involves hyperactivity in multiple arms of the innate immune system.

Patients with PASH syndrome have severely impaired quality of life and often experience social withdrawal due to the disfiguring sequelae and limited treatment options available. To improve patient outcomes, it is essential for physicians and scientists to report on successful treatment strategies and advances in immunologic understanding. Improved understanding of PASH syndrome calls for further genetic exploration into the role of additional genomic repeats and how these affect the PSTPIP1 gene and inflammasome activity. As medical advances improve understanding of the pathophysiology of this disease entity, it will likely become clear which mechanisms are most important in disease progression and how clinicians can best optimize treatment.

Pyoderma gangrenosum (PG), acne, and hidradenitis suppurativa (HS)(PASH) syndrome is a recently identified disease process within the spectrum of autoinflammatory diseases (AIDs), which are distinct from autoimmune, infectious, and allergic syndromes and are gaining increasing interest given their complex pathophysiology and therapeutic resistance.¹ Autoinflammatory diseases are defined by a dysregulation of the innate immune system in the absence of typical autoimmune features, including autoantibodies and antigen-specific T lymphocytes.² Mutations affecting proteins of the inflammasome or proteins involved in regulating inflammasome function have been associated with these AIDs.²

Many AIDs have cutaneous involvement, as seen in PASH syndrome. Pyoderma gangrenosum is a neutrophilic dermatosis presenting as skin ulcers with undermined, erythematous, violaceous borders. It can be isolated, syndromic, or associated with inflammatory conditions (eg, inflammatory bowel disease, rheumatologic disorders, hematologic disorders).¹ Acne vulgaris develops because of chronic obstruction of hair follicles as a result of disordered keratinization and abnormal sebaceous stem cell differentiation.²Propionibacterium acnes can reside and replicate within the biofilm community of the hair follicle and activate the inflammasome.^2,3 Hidradenitis suppurativa, a chronic relapsing neutrophilic dermatosis, is a debilitating inflammatory disease of the hair follicles involving apocrine gland–bearing skin (ie, the axillary, inguinal, and anogenital regions).² Onset often occurs between the ages of 20 and 40 years, with a 3-fold higher incidence in women compared to men.³ Patients experience painful, deep-seated nodules that drain into sinus tracts and abscesses. The condition can be isolated or associated with inflammatory conditions, such as inflammatory bowel disease.⁴

PASH syndrome has been described as a polygenic autoinflammatory condition that most commonly presents in young adults, with onset of acne beginning years prior to other manifestations. A study analyzing 5 patients with PASH syndrome reported an average age of 32.2 years at diagnosis with a disease duration of 3 to 7 years.⁵ Pathophysiology of this condition is not well understood, with many hypotheses calling upon dysregulation of the innate immune system, a commonality this syndrome may share with other AIDs. Given its poorly understood pathophysiology, treating PASH syndrome can be especially difficult. We report a novel case of disease remission lasting more than 4 years using adalimumab and cyclosporine. We also discuss prior treatment successes and hypotheses regarding etiologic factors in PASH syndrome.

Case Report

A 36-year-old woman presented for evaluation of open draining ulcerations on the back of 18 months’ duration. She had a 16-year history of scarring cystic acne of the face and HS of the groin. The patient’s family history was remarkable for severe cystic acne in her brother and son as well as HS in her mother and another brother. Her treatment history included isotretinoin, doxycycline, and topical steroids.

Physical examination revealed 2 ulcerations with violaceous borders involving the left upper back (greatest diameter, 5×7 cm)(Figure 1). Evidence of papular and cystic acne with residual scarring was noted on the cheeks. Scarring from HS was noted in the axillae and right groin. A biopsy from the edge of an ulceration on the back demonstrated epidermal spongiosis with acute and chronic inflammation and fibrosis (Figure 2). The clinicopathologic findings were most consistent with PG, and the patient was diagnosed with PASH syndrome, given the constellation of cutaneous lesions.

After treatment with topical and systemic antibiotics for acne and HS for more than 1 year failed, the patient was started on adalimumab. The initial dose was 160 mg subcutaneously, then 80 mg 2 weeks later, then 40 mg weekly thereafter. Doxycycline was continued for treatment of the acne and HS. After 6 weeks of adalimumab, the PG worsened and prednisone was added. She developed tender furuncles on the back, and cultures grew Pseudomonas aeruginosa and methicillin-sensitive Staphylococcus aureus that responded to ciprofloxacin and cephalexin.

Due to progression of PG on adalimumab, switching to an infliximab infusion or anakinra was considered, but these options were not covered by the patient’s health insurance. Three months after the initial presentation, the patient was started on cyclosporine 100 mg 3 times daily (5 mg/kg/d) while adalimumab was continued; the ulcers started to improve within 2.5 weeks. After 3 months (Figure 3), the cyclosporine was reduced to 100 mg twice daily, and adalimumab was continued. She had a slight flare of PG after 8 months of treatment when adalimumab was unavailable to her for 2 months. After 8 months on cyclosporine, the dosage was tapered to 100 mg/d and then completely discontinued after 12 months.

The patient has continued on adalimumab 40 mg weekly with excellent control of the PG (Figure 4), although she did have one HS flare in the left axilla 11 months after the initial treatment. The patient’s cystic acne has intermittently flared and has been managed with spironolactone 100 mg/d for 3 years. After 4 years of management, the patient’s PG and HS remain well controlled on adalimumab.

Comment

Our case represents a major step in refining long-term treatment approaches for PASH syndrome due to the 4-year remission. Prior cases have reported use of anakinra, anakinra-cyclosporine combination, prednisone, azathioprine, topical tacrolimus, etanercept, and dapsone without sustainable success.^1-6 The case studies discussed below have achieved remission via alternative drug combinations.

Staub et al⁴ found greatest success with a combination of infliximab, dapsone, and cyclosporine, and their patient had been in remission for 20 months at time of publication. Their hypothesis proposed that multiple inflammatory signaling pathways are involved in PASH syndrome, and this is why combination therapy is required for remission.⁴ In 2018, Lamiaux et al⁷ demonstrated successful treatment with rifampicin and clindamycin. Their patient had been in remission for 22 months at the time of publication—this time frame included 12 months of combination therapy and 10 months without medication. The authors hypothesized that, because of the autoinflammatory nature of these antibiotics, this pharmacologic combination could eradicate pathogenic bacteria from host microbiota while also inhibiting neutrophil function and synthesis of chemokines and cytokines.⁷

More recently, reports have been published regarding the success of tildrakizumab, an IL-23 antagonist, and ixekizumab, an IL-17 antagonist, in the treatment of PASH syndrome.^6,8 Ixekizumab was used in combination with doxycycline, and remission was achieved in 12 months.⁸ However, tildrakizumab was used alone and achieved greater than 75% improvement in disease manifestations within 2 months.

Marzano et al⁵ conducted protein arrays and enzyme-linked immunosorbent assay to analyze the expression of cytokine, chemokine, and effector molecule profiles in PASH syndrome. It was determined that serum analysis displayed a normal cytokine/chemokine profile, with the only abnormalities being anemia and elevated C-reactive protein. There were no statistically significant differences in serum levels of IL-1β, tumor necrosis factor (TNF) α, or IL-17 between PASH syndrome and healthy controls. However, cutaneous analysis revealed extensive cytokine and chemokine hyperactivity for IL-1β and IL-1β receptor; TNF-α; C-X-C motif ligands 1, 2, and 3; C-X-C motif ligand 16; regulated on activation, normal T cell expressed and secreted; IL-17 and IL-17R; Fas/Fas ligand; and CD40/CD40L. This cutaneous profile of elevated cytokines and chemokines mirrors that of nonsyndromic PG and many other AIDs. These results demonstrate that the inflammation in PASH syndrome is localized mainly to the skin and further support the hypothesis that possibilities for alternative treatment options are diverse.⁵

Ead et al³ presented a unique perspective focusing on cutaneous biofilm involvement in PASH syndrome. Microbes within these biofilms induce the migration and proliferation of inflammatory cells that consume factors normally utilized for tissue catabolism. These organisms deplete necessary biochemical cofactors used during healing. This lack of nutrients needed for healing not only slows the process but also promotes favorable conditions for the growth of anerobic species. In conjunction, biofilm formation restricts bacterial access to oxygen and nutrients, thus decreasing the bacterial metabolic rate and preventing the effects of antibiotic therapy. These features of biofilm communities contribute to inflammation and possibly the troubling resistance to many therapeutic options for PASH syndrome.

Each component of PASH syndrome has been associated with biofilm formation. As previously described, PG manifests in the skin as painful ulcerations, often with slough. This slough is hypothesized to be a consequence of increased vascular permeability and exudative byproducts that accompany the inflammatory nature of biofilms.³ Acne vulgaris has well-described associations with P acnes. Ead et al³ described P acnes as a component of the biofilm community within the microcomedone of hair follicles. This biofilm allows for antibiotic resistance occasionally seen in the treatment of acne and is potentially the pathogenic factor that both impedes healing and enhances the inflammatory state. Hidradenitis suppurativa has been associated with biofilm formation.³

In further pursuit of PASH syndrome pathophysiology, many experts have sought to uncover the relationship between PASH syndrome and the previously described pyogenic arthritis, PG, and acne (PAPA) syndrome, another entity within the AIDs spectrum (Table). This condition was first recognized in 1997 in a 3-generation family with 10 affected members.¹ It is characterized by PG and acne, similar to PASH; however, PAPA syndrome includes PG arthritis and lacks HS. Pyogenic arthritis manifests as recurrent aseptic inflammation of the joints, mainly the elbows, knees, and ankles. Pyogenic arthritis commonly is the presenting symptom of PAPA syndrome, with onset in childhood.² As patients age, the arthritic symptoms decrease, and skin manifestations become more prominent.

PAPA syndrome has autosomal-dominant inheritance with mutations on chromosome 15 in the proline-serine-threonine phosphatase interacting protein 1 (PSTPIP1) gene.¹ This mutation induces hyperphosphorylation of PSTPIP1, allowing for increased binding affinity to pyrin. Both PSTPIP1 and pyrin are co-expressed as parts of the NLRP3 inflammasome in granulocytes and monocytes.¹ As a result, pyrin is more highly bound and loses its inhibitory effect on the NLRP3 inflammasome pathway. This lack of inhibition allows for uninhibited cleavage of pro–IL-1β to active IL-1β by the inflammasome.¹

Elevated concentrations of IL-1β in patients with PAPA syndrome result in a dysregulation of the innate immune system. IL-1β induces the release of proinflammatory cytokines, namely TNF-α; interferon γ; IL-8; and regulated on activation, normal T cell expressed and secreted (RANTES), all of which activate neutrophils and induce neutrophilic inflammation.² IL-1β not only initiates this entire cascade but also acts as an antiapoptotic signal for neutrophils.² When IL-1β reaches a critical threshold, it induces enough inflammation to cause severe tissue damage, thus causing joint and cutaneous disease in PAPA syndrome. IL-1 inhibitors (anakinra) or TNF-α inhibitors (etanercept, adalimumab, infliximab) have been used many times to successfully treat PAPA syndrome, with TNF-α inhibitors providing the most consistent results.

Another AIDs entity with similarities to both PAPA syndrome and PASH syndrome is pyogenic arthritis, PG, acne, and HS (PA-PASH) syndrome. First identified in 2012 by Bruzzese,⁹ genetic analyses revealed a p.E277D missense mutation in PSTPIP1 in PA-PASH syndrome. Research has suggested that the key molecular feature is neutrophil activation by T_H17 cells and the TNF-α axis.⁹ This syndrome has not been further characterized, and little is known regarding adequate treatment for PA-PASH syndrome.

Although it is similar in phenotype to aspects of PAPA and PA-PASH syndromes, PASH syndrome has distinct genotypic and immunologic abnormalities. Genetic analysis of this condition has shown an increased number of CCTG repeats in proximity to the PSTPIP1 promoter. It is hypothesized that these additional repeats predispose patients to neutrophilic inflammation in a similar manner to a condition described in France, termed aseptic abscess syndrome.^1,5 Other mutations have been identified, including those in IL-1N, PSMB8, MEFV, NOD2, NCSTN, and more.^2,7 However, it has been determined that the majority of these variants have already been filed in the Single Nucleotide Polymorphism Database or in the Registry of Hereditary Auto-inflammatory Disorders Mutations.² The question remains regarding the origin of inflammation seen in PASH syndrome; the potential role of biofilms; and the relationship between PASH, PAPA, and PA-PASH syndromes. Much work remains to be done in refining therapeutic options for PASH syndrome. Continued biochemical research is necessary, as well as collaboration among dermatologists worldwide who find success in treating this condition.

Conclusion

There are genotypic and phenotypic similarities between PASH, PAPA, and PA-PASH syndromes, with various mutations within or near the PSTPIP1 gene; however, their genetic discrepancies seem to play a major role in the pathophysiology of each syndrome. Much work remains to be done in PA-PASH syndrome, which has not yet been well described. Meanwhile, PAPA syndrome has been well characterized with mutations affecting proteins of the NLRP3 inflammasome, resulting in elevated IL-1β and excess neutrophilic inflammation. In PASH syndrome, the importance of increased repeats near the PSTPIP1 promoter is yet to be elucidated. It has been shown that these abnormalities predispose individuals to neutrophilic inflammation, but the mechanism by which they do so is unknown. In addition, consideration of biofilms and their predisposition to inflammation within the pathophysiology of PASH syndrome is a possibility that must be considered when discussing therapeutic options. Based on our case study and previous successes in treating PASH syndrome, it is clear that a multidrug approach is necessary for remission. It is likely that the etiology of PASH syndrome is multifaceted and involves hyperactivity in multiple arms of the innate immune system.

Patients with PASH syndrome have severely impaired quality of life and often experience social withdrawal due to the disfiguring sequelae and limited treatment options available. To improve patient outcomes, it is essential for physicians and scientists to report on successful treatment strategies and advances in immunologic understanding. Improved understanding of PASH syndrome calls for further genetic exploration into the role of additional genomic repeats and how these affect the PSTPIP1 gene and inflammasome activity. As medical advances improve understanding of the pathophysiology of this disease entity, it will likely become clear which mechanisms are most important in disease progression and how clinicians can best optimize treatment.

Throughout the COVID-19 pandemic, there has been a striking paucity of representations of patients with skin of color (SOC) in the dermatology literature. Was COVID-19 underdiagnosed in this patient population due to a lack of patient-centered resources and inadequate dermatology training; reduced access to care, resulting from social determinants of health and reduced skin-color concordance; or the absence of population-based prevalence studies?

Tan et al¹ reviewed 51 articles describing skin findings secondary to COVID-19. Patients were stratified by country of origin, which yielded an increased prevalence of cutaneous manifestations among Americans and Europeans compared to Asians, but patients were not stratified by race.¹ However, in one case series of 318 predominantly American patients, 89% were White and 0.7% were Black.² This systematic review by Tan et al¹ suggested that skin manifestations of COVID-19 were present in patients with SOC but less frequently than in White patients. However, case series are not a strong proxy for population-level prevalence.

More broadly, patients with SOC are underrepresented in Google image search results, as the medical resource websites (eg, DermNet [https://dermnetnz.org], MedicalNewsToday [www.medicalnewstoday.com], and Healthline [www.healthline.com]) are lacking these images.³ As a result, it is difficult for patients with SOC to recognize diseases presenting in darker skin types. This same tendency may exist for COVID-19 skin manifestations. A systematic review found that articles describing cutaneous manifestations of COVID-19 almost exclusively presented images of lighter skin and completely omitted darker skin.⁴ If images of patients with SOC are absent from online resources, it is increasingly unlikely for these patients to recognize if their skin lesions are associated with COVID-19, which may result in a decrease in the number of patients with SOC presenting with skin lesions secondary to COVID-19, thereby influencing the representation of patients with SOC in case studies.

The lack of representation of SOC in online resources mirrors the paucity of images in dermatology textbooks. According to a search of 7170 images in major dermatology textbooks, most images depicted light or white skin (80.6%), followed by medium or brown skin in 15.5% of images and dark or black skin in only 3.9%.⁵ Physicians rely on online and print resources for making diagnoses; inadequate resources highlight a component of a larger issue: inadequate training of dermatologists in SOC. In a survey of American dermatologists and dermatology residents (N=262), 47% thought that their medical education had not adequately trained them on skin conditions in Black patients.⁶

A lack of adequate training for dermatologists may decrease the rate of correct diagnosis of skin lesions secondary to COVID-19 in patients with SOC. A lack of trust in the health care system and social determinants of health may hinder patients with SOC from seeking medical help. Dermatology is the second least diverse of medical specialties; only 3% of dermatologists are Black.⁷ This is impactful: First, because minority physicians are increasingly likely to provide care for patients of the same race or background, and second, because race-concordant physician visits are associated with greater patient-reported positive affect.⁷ A lack of availability of race-concordant physicians or physicians with perceived cultural competence may deter patients with SOC from seeking help, which may be further prevalent in dermatologic practice.

Barriers at all levels of social determinants of health hinder access to health care. Patients with SOC experience greater housing insecurity, increased reliance on public transportation, more issues with health literacy, and limited English-language fluency.⁸ Combined, these factors equate to decreased access to health care resources and subsequently a lack of inclusion in case studies.

COVID-19 infection disproportionately affects patients with SOC,⁸ but there is a clear lack of representation of SOC in the COVID-19 dermatology literature. It is imperative to investigate factors that may contribute to this inequity. Recognizing skin manifestations can play a role in diagnosing COVID-19; increased awareness of its presentation in darker skin types may help bridge existing racial inequities. It is vital that physicians receive adequate resources and training to be able to recognize cutaneous manifestations of COVID-19 in all skin types. Finally, it is important to recognize that the lack of representation of SOC in the COVID-19 literature represents a larger trend that exists in dermatologic research that warrants further investigation and advocacy for inclusivity.

Throughout the COVID-19 pandemic, there has been a striking paucity of representations of patients with skin of color (SOC) in the dermatology literature. Was COVID-19 underdiagnosed in this patient population due to a lack of patient-centered resources and inadequate dermatology training; reduced access to care, resulting from social determinants of health and reduced skin-color concordance; or the absence of population-based prevalence studies?

Tan et al¹ reviewed 51 articles describing skin findings secondary to COVID-19. Patients were stratified by country of origin, which yielded an increased prevalence of cutaneous manifestations among Americans and Europeans compared to Asians, but patients were not stratified by race.¹ However, in one case series of 318 predominantly American patients, 89% were White and 0.7% were Black.² This systematic review by Tan et al¹ suggested that skin manifestations of COVID-19 were present in patients with SOC but less frequently than in White patients. However, case series are not a strong proxy for population-level prevalence.

More broadly, patients with SOC are underrepresented in Google image search results, as the medical resource websites (eg, DermNet [https://dermnetnz.org], MedicalNewsToday [www.medicalnewstoday.com], and Healthline [www.healthline.com]) are lacking these images.³ As a result, it is difficult for patients with SOC to recognize diseases presenting in darker skin types. This same tendency may exist for COVID-19 skin manifestations. A systematic review found that articles describing cutaneous manifestations of COVID-19 almost exclusively presented images of lighter skin and completely omitted darker skin.⁴ If images of patients with SOC are absent from online resources, it is increasingly unlikely for these patients to recognize if their skin lesions are associated with COVID-19, which may result in a decrease in the number of patients with SOC presenting with skin lesions secondary to COVID-19, thereby influencing the representation of patients with SOC in case studies.

The lack of representation of SOC in online resources mirrors the paucity of images in dermatology textbooks. According to a search of 7170 images in major dermatology textbooks, most images depicted light or white skin (80.6%), followed by medium or brown skin in 15.5% of images and dark or black skin in only 3.9%.⁵ Physicians rely on online and print resources for making diagnoses; inadequate resources highlight a component of a larger issue: inadequate training of dermatologists in SOC. In a survey of American dermatologists and dermatology residents (N=262), 47% thought that their medical education had not adequately trained them on skin conditions in Black patients.⁶

A lack of adequate training for dermatologists may decrease the rate of correct diagnosis of skin lesions secondary to COVID-19 in patients with SOC. A lack of trust in the health care system and social determinants of health may hinder patients with SOC from seeking medical help. Dermatology is the second least diverse of medical specialties; only 3% of dermatologists are Black.⁷ This is impactful: First, because minority physicians are increasingly likely to provide care for patients of the same race or background, and second, because race-concordant physician visits are associated with greater patient-reported positive affect.⁷ A lack of availability of race-concordant physicians or physicians with perceived cultural competence may deter patients with SOC from seeking help, which may be further prevalent in dermatologic practice.

Barriers at all levels of social determinants of health hinder access to health care. Patients with SOC experience greater housing insecurity, increased reliance on public transportation, more issues with health literacy, and limited English-language fluency.⁸ Combined, these factors equate to decreased access to health care resources and subsequently a lack of inclusion in case studies.

COVID-19 infection disproportionately affects patients with SOC,⁸ but there is a clear lack of representation of SOC in the COVID-19 dermatology literature. It is imperative to investigate factors that may contribute to this inequity. Recognizing skin manifestations can play a role in diagnosing COVID-19; increased awareness of its presentation in darker skin types may help bridge existing racial inequities. It is vital that physicians receive adequate resources and training to be able to recognize cutaneous manifestations of COVID-19 in all skin types. Finally, it is important to recognize that the lack of representation of SOC in the COVID-19 literature represents a larger trend that exists in dermatologic research that warrants further investigation and advocacy for inclusivity.

Throughout the COVID-19 pandemic, there has been a striking paucity of representations of patients with skin of color (SOC) in the dermatology literature. Was COVID-19 underdiagnosed in this patient population due to a lack of patient-centered resources and inadequate dermatology training; reduced access to care, resulting from social determinants of health and reduced skin-color concordance; or the absence of population-based prevalence studies?

Tan et al¹ reviewed 51 articles describing skin findings secondary to COVID-19. Patients were stratified by country of origin, which yielded an increased prevalence of cutaneous manifestations among Americans and Europeans compared to Asians, but patients were not stratified by race.¹ However, in one case series of 318 predominantly American patients, 89% were White and 0.7% were Black.² This systematic review by Tan et al¹ suggested that skin manifestations of COVID-19 were present in patients with SOC but less frequently than in White patients. However, case series are not a strong proxy for population-level prevalence.

More broadly, patients with SOC are underrepresented in Google image search results, as the medical resource websites (eg, DermNet [https://dermnetnz.org], MedicalNewsToday [www.medicalnewstoday.com], and Healthline [www.healthline.com]) are lacking these images.³ As a result, it is difficult for patients with SOC to recognize diseases presenting in darker skin types. This same tendency may exist for COVID-19 skin manifestations. A systematic review found that articles describing cutaneous manifestations of COVID-19 almost exclusively presented images of lighter skin and completely omitted darker skin.⁴ If images of patients with SOC are absent from online resources, it is increasingly unlikely for these patients to recognize if their skin lesions are associated with COVID-19, which may result in a decrease in the number of patients with SOC presenting with skin lesions secondary to COVID-19, thereby influencing the representation of patients with SOC in case studies.

The lack of representation of SOC in online resources mirrors the paucity of images in dermatology textbooks. According to a search of 7170 images in major dermatology textbooks, most images depicted light or white skin (80.6%), followed by medium or brown skin in 15.5% of images and dark or black skin in only 3.9%.⁵ Physicians rely on online and print resources for making diagnoses; inadequate resources highlight a component of a larger issue: inadequate training of dermatologists in SOC. In a survey of American dermatologists and dermatology residents (N=262), 47% thought that their medical education had not adequately trained them on skin conditions in Black patients.⁶

A lack of adequate training for dermatologists may decrease the rate of correct diagnosis of skin lesions secondary to COVID-19 in patients with SOC. A lack of trust in the health care system and social determinants of health may hinder patients with SOC from seeking medical help. Dermatology is the second least diverse of medical specialties; only 3% of dermatologists are Black.⁷ This is impactful: First, because minority physicians are increasingly likely to provide care for patients of the same race or background, and second, because race-concordant physician visits are associated with greater patient-reported positive affect.⁷ A lack of availability of race-concordant physicians or physicians with perceived cultural competence may deter patients with SOC from seeking help, which may be further prevalent in dermatologic practice.

Barriers at all levels of social determinants of health hinder access to health care. Patients with SOC experience greater housing insecurity, increased reliance on public transportation, more issues with health literacy, and limited English-language fluency.⁸ Combined, these factors equate to decreased access to health care resources and subsequently a lack of inclusion in case studies.

COVID-19 infection disproportionately affects patients with SOC,⁸ but there is a clear lack of representation of SOC in the COVID-19 dermatology literature. It is imperative to investigate factors that may contribute to this inequity. Recognizing skin manifestations can play a role in diagnosing COVID-19; increased awareness of its presentation in darker skin types may help bridge existing racial inequities. It is vital that physicians receive adequate resources and training to be able to recognize cutaneous manifestations of COVID-19 in all skin types. Finally, it is important to recognize that the lack of representation of SOC in the COVID-19 literature represents a larger trend that exists in dermatologic research that warrants further investigation and advocacy for inclusivity.

THE COMPARISON

A A 23-year-old White woman with malar erythema from acute cutaneous lupus erythematosus. The erythema also can be seen on the nose and eyelids but spares the nasolabial folds.

B A Black woman with malar erythema and hyperpigmentation from acute cutaneous lupus erythematosus. The nasolabial folds are spared.

C A 19-year-old Latina woman with malar erythema from acute cutaneous lupus erythematosus. The erythema also can be seen on the nose, chin, and eyelids but spares the nasolabial folds. Cutaneous erosions are present on the right cheek as part of the lupus flare. Systemic lupus erythematosus (SLE) is a chronic autoimmune condition that affects the kidneys, lungs, brain, and heart, though it is not limited to these organs. Dermatologists and primary care physicians play a critical role in the early identification of SLE, particularly in those with skin of color, as the standardized mortality rate is 2.6-fold higher in patients with SLE compared to the general population.¹ The clinical manifestations of SLE vary.

Photographs courtesy of Richard P. Usatine, MD.

Epidemiology

A meta-analysis of data from the Centers for Disease Control and Prevention National Lupus Registry network including 5417 patients revealed a prevalence of 72.8 cases per 100,000 person-years.² The prevalence was higher in females than males and highest among females identifying as Black. White and Asian/Pacific Islander females had the lowest prevalence. The American Indian (indigenous)/Alaska Native–identifying population had the highest race-specific SLE estimates among both females and males compared to other racial/ethnic groups.²

Key clinical features in people with darker skin tones

The diagnosis of SLE is based on clinical and immunologic criteria from the European League Against Rheumatism/American College of Rheumatology.^3,4 An antinuclear antibody titer of 1:80 or higher at least once is required for the diagnosis of SLE, as long as there is not another more likely diagnosis. If it is present, 22 additive weighted classification criteria are considered; each criterion is assigned points, ranging from 2 to 10. Patients with at least 1 clinical criterion and 10 or more points are classified as having SLE. If more than 1 of the criteria are met in a domain, then the one with the highest numerical value is counted.^3,4 Aringer et al^3,4 outline the criteria and numerical points to make the diagnosis of SLE. The mucocutaneous component of the SLE diagnostic criteria^3,4 includes nonscarring alopecia, oral ulcers, subacute cutaneous or discoid lupus erythematosus,⁵ and acute cutaneous lupus erythematosus, with acute cutaneous lupus erythematosus being the highest-weighted criterion in that domain. The other clinical domains are constitutional, hematologic, neuropsychiatric, serosal, musculoskeletal, renal, antiphosopholipid antibodies, complement proteins, and SLE-specific antibodies.^3,4

The malar (“butterfly”) rash of SLE characteristically includes erythema that spares the nasolabial folds but affects the nasal bridge and cheeks.⁶ The rash occasionally may be pruritic and painful, lasting days to weeks. Photosensitivity occurs, resulting in rashes or even an overall worsening of SLE symptoms. In those with darker skin tones, erythema may appear violaceous or may not be as readily appreciated.⁶

Worth noting

• Patients with skin of color are at an increased risk for postinflammatory hypopigmentation and hyperpigmentation (pigment alteration), hypertrophic scars, and keloids.^7,8

• The mortality rate for those with SLE is high despite early recognition and treatment when compared to the general population.^1,9

Health disparity highlight

Those at greatest risk for death from SLE in the United States are those of African descent, Hispanic individuals, men, and those with low socioeconomic status,⁹ which likely is primarily driven by social determinants of health instead of genetic patterns. Income level, educational attainment, insurance status, and environmental factors¹⁰ have far-reaching effects, negatively impacting quality of life and even mortality.

THE COMPARISON

A A 23-year-old White woman with malar erythema from acute cutaneous lupus erythematosus. The erythema also can be seen on the nose and eyelids but spares the nasolabial folds.

B A Black woman with malar erythema and hyperpigmentation from acute cutaneous lupus erythematosus. The nasolabial folds are spared.

C A 19-year-old Latina woman with malar erythema from acute cutaneous lupus erythematosus. The erythema also can be seen on the nose, chin, and eyelids but spares the nasolabial folds. Cutaneous erosions are present on the right cheek as part of the lupus flare. Systemic lupus erythematosus (SLE) is a chronic autoimmune condition that affects the kidneys, lungs, brain, and heart, though it is not limited to these organs. Dermatologists and primary care physicians play a critical role in the early identification of SLE, particularly in those with skin of color, as the standardized mortality rate is 2.6-fold higher in patients with SLE compared to the general population.¹ The clinical manifestations of SLE vary.

Photographs courtesy of Richard P. Usatine, MD.

Epidemiology

A meta-analysis of data from the Centers for Disease Control and Prevention National Lupus Registry network including 5417 patients revealed a prevalence of 72.8 cases per 100,000 person-years.² The prevalence was higher in females than males and highest among females identifying as Black. White and Asian/Pacific Islander females had the lowest prevalence. The American Indian (indigenous)/Alaska Native–identifying population had the highest race-specific SLE estimates among both females and males compared to other racial/ethnic groups.²

Key clinical features in people with darker skin tones

The diagnosis of SLE is based on clinical and immunologic criteria from the European League Against Rheumatism/American College of Rheumatology.^3,4 An antinuclear antibody titer of 1:80 or higher at least once is required for the diagnosis of SLE, as long as there is not another more likely diagnosis. If it is present, 22 additive weighted classification criteria are considered; each criterion is assigned points, ranging from 2 to 10. Patients with at least 1 clinical criterion and 10 or more points are classified as having SLE. If more than 1 of the criteria are met in a domain, then the one with the highest numerical value is counted.^3,4 Aringer et al^3,4 outline the criteria and numerical points to make the diagnosis of SLE. The mucocutaneous component of the SLE diagnostic criteria^3,4 includes nonscarring alopecia, oral ulcers, subacute cutaneous or discoid lupus erythematosus,⁵ and acute cutaneous lupus erythematosus, with acute cutaneous lupus erythematosus being the highest-weighted criterion in that domain. The other clinical domains are constitutional, hematologic, neuropsychiatric, serosal, musculoskeletal, renal, antiphosopholipid antibodies, complement proteins, and SLE-specific antibodies.^3,4

The malar (“butterfly”) rash of SLE characteristically includes erythema that spares the nasolabial folds but affects the nasal bridge and cheeks.⁶ The rash occasionally may be pruritic and painful, lasting days to weeks. Photosensitivity occurs, resulting in rashes or even an overall worsening of SLE symptoms. In those with darker skin tones, erythema may appear violaceous or may not be as readily appreciated.⁶

Worth noting

• Patients with skin of color are at an increased risk for postinflammatory hypopigmentation and hyperpigmentation (pigment alteration), hypertrophic scars, and keloids.^7,8

• The mortality rate for those with SLE is high despite early recognition and treatment when compared to the general population.^1,9

Health disparity highlight

Those at greatest risk for death from SLE in the United States are those of African descent, Hispanic individuals, men, and those with low socioeconomic status,⁹ which likely is primarily driven by social determinants of health instead of genetic patterns. Income level, educational attainment, insurance status, and environmental factors¹⁰ have far-reaching effects, negatively impacting quality of life and even mortality.

THE COMPARISON

A A 23-year-old White woman with malar erythema from acute cutaneous lupus erythematosus. The erythema also can be seen on the nose and eyelids but spares the nasolabial folds.

B A Black woman with malar erythema and hyperpigmentation from acute cutaneous lupus erythematosus. The nasolabial folds are spared.

C A 19-year-old Latina woman with malar erythema from acute cutaneous lupus erythematosus. The erythema also can be seen on the nose, chin, and eyelids but spares the nasolabial folds. Cutaneous erosions are present on the right cheek as part of the lupus flare. Systemic lupus erythematosus (SLE) is a chronic autoimmune condition that affects the kidneys, lungs, brain, and heart, though it is not limited to these organs. Dermatologists and primary care physicians play a critical role in the early identification of SLE, particularly in those with skin of color, as the standardized mortality rate is 2.6-fold higher in patients with SLE compared to the general population.¹ The clinical manifestations of SLE vary.

Photographs courtesy of Richard P. Usatine, MD.

Epidemiology

A meta-analysis of data from the Centers for Disease Control and Prevention National Lupus Registry network including 5417 patients revealed a prevalence of 72.8 cases per 100,000 person-years.² The prevalence was higher in females than males and highest among females identifying as Black. White and Asian/Pacific Islander females had the lowest prevalence. The American Indian (indigenous)/Alaska Native–identifying population had the highest race-specific SLE estimates among both females and males compared to other racial/ethnic groups.²

Key clinical features in people with darker skin tones

The diagnosis of SLE is based on clinical and immunologic criteria from the European League Against Rheumatism/American College of Rheumatology.^3,4 An antinuclear antibody titer of 1:80 or higher at least once is required for the diagnosis of SLE, as long as there is not another more likely diagnosis. If it is present, 22 additive weighted classification criteria are considered; each criterion is assigned points, ranging from 2 to 10. Patients with at least 1 clinical criterion and 10 or more points are classified as having SLE. If more than 1 of the criteria are met in a domain, then the one with the highest numerical value is counted.^3,4 Aringer et al^3,4 outline the criteria and numerical points to make the diagnosis of SLE. The mucocutaneous component of the SLE diagnostic criteria^3,4 includes nonscarring alopecia, oral ulcers, subacute cutaneous or discoid lupus erythematosus,⁵ and acute cutaneous lupus erythematosus, with acute cutaneous lupus erythematosus being the highest-weighted criterion in that domain. The other clinical domains are constitutional, hematologic, neuropsychiatric, serosal, musculoskeletal, renal, antiphosopholipid antibodies, complement proteins, and SLE-specific antibodies.^3,4

The malar (“butterfly”) rash of SLE characteristically includes erythema that spares the nasolabial folds but affects the nasal bridge and cheeks.⁶ The rash occasionally may be pruritic and painful, lasting days to weeks. Photosensitivity occurs, resulting in rashes or even an overall worsening of SLE symptoms. In those with darker skin tones, erythema may appear violaceous or may not be as readily appreciated.⁶

Worth noting

• Patients with skin of color are at an increased risk for postinflammatory hypopigmentation and hyperpigmentation (pigment alteration), hypertrophic scars, and keloids.^7,8

• The mortality rate for those with SLE is high despite early recognition and treatment when compared to the general population.^1,9

Health disparity highlight

Those at greatest risk for death from SLE in the United States are those of African descent, Hispanic individuals, men, and those with low socioeconomic status,⁹ which likely is primarily driven by social determinants of health instead of genetic patterns. Income level, educational attainment, insurance status, and environmental factors¹⁰ have far-reaching effects, negatively impacting quality of life and even mortality.

To the Editor:

Dermatology is one of the most competitive residencies for matching, with a 57.5% match rate in 2022.¹ Our prior study of research-mentor relationships among matched dermatology applicants corroborated the importance of home programs (HPs) and program connections.² Therefore, our current objective was to compare profiles of matched dermatology applicants without HPs vs those with HPs.

We searched websites of 139 dermatology programs nationwide and found 1736 matched applicants from 2016 to 2020; of them, 323 did not have HPs. We determined program rank by research output using Doximity Residency Navigator (https://www.doximity.com/residency/). Advanced degrees (ADs) of applicants were identified using program websites and LinkedIn. A PubMed search was conducted for number of articles published by each applicant before September 15 of their match year. For applicants without HPs, we identified the senior author on each publication. The senior author publishing with an applicant most often was considered the research mentor. Two-tailed independent t tests and χ² tests were used to determine statistical significance (P<.05).

On average, matched applicants without HPs matched in lower-ranked (74.4) and smaller (12.4) programs compared with matched applicants with HPs (45.3 [P<.0001] and 15.1 [P<.0001], respectively)(eTable). The mean number of publications was similar between matched applicants with HPs and without HPs (5.64 and 4.80, respectively; P=.0525) as well as the percentage with ADs (14.7% and 11.5%, respectively; P=.0953). Overall, 14.8% of matched applicants without HPs matched at their mentors’ institutions.

Data were obtained for matched international applicants as a subset of non-HP applicants. Despite attending medical schools without associated HPs in the United States, international applicants matched at similarly ranked (44.3) and sized (15.0) programs, on average, compared with HP applicants. The mean number of publications was higher for international applicants (11.4) vs domestic applicants (5.33). International applicants more often had ADs (23.8%) and 60.1% of them held doctor of philosophy degrees. Overall, 40.5% of international applicants matched at their mentors’ institutions.

Our study suggests that matched dermatology applicants with and without HPs had similar achievements, on average, for the number of publications and percentage with ADs. However, non-HP applicants matched at lower-ranked programs than HP applicants. Therefore, applicants without HPs should strongly consider cultivating program connections, especially if they desire to match at higher-ranked dermatology programs. To illustrate, the rate of matching at research mentors’ institutions was approximately 3-times higher for international applicants than non-HP applicants overall. Despite the disadvantages of applying as international applicants, they were able to match at substantially higher-ranked dermatology programs than non-HP applicants. International applicants may have a longer time investment—the number of years from obtaining their medical degree or US medical license to matching—giving them time to produce quality research and develop meaningful relationships at an institution. Additionally, our prior study of the top 25 dermatology residencies showed that 26.2% of successful applicants matched at their research mentors’ institutions, with almost half of this subset matching at their HPs, where their mentors also practiced.² Because of the potential benefits of having program connections, applicants without HPs should seek dermatology research mentors, especially via highly beneficial in-person networking opportunities (eg, away rotations, conferences) that had previously been limited during the COVID-19 pandemic.³ Formal mentorship programs giving priority to students without HPs recently have been developed, which only begins to address the inequities in the dermatology residency application process.⁴

Study limitations include lack of resident information on 15 program websites, missed publications due to applicant name changes, not accounting for abstracts and posters, and inability to collect data on unmatched applicants.

We hope that our study alleviates some concerns that applicants without HPs may have regarding applying for dermatology residency and encourages those with a genuine interest in dermatology to pursue the specialty, provided they find a strong research mentor. Residency programs should be cognizant of the unique challenges that non-HP applicants face for matching.

To the Editor:

Dermatology is one of the most competitive residencies for matching, with a 57.5% match rate in 2022.¹ Our prior study of research-mentor relationships among matched dermatology applicants corroborated the importance of home programs (HPs) and program connections.² Therefore, our current objective was to compare profiles of matched dermatology applicants without HPs vs those with HPs.

We searched websites of 139 dermatology programs nationwide and found 1736 matched applicants from 2016 to 2020; of them, 323 did not have HPs. We determined program rank by research output using Doximity Residency Navigator (https://www.doximity.com/residency/). Advanced degrees (ADs) of applicants were identified using program websites and LinkedIn. A PubMed search was conducted for number of articles published by each applicant before September 15 of their match year. For applicants without HPs, we identified the senior author on each publication. The senior author publishing with an applicant most often was considered the research mentor. Two-tailed independent t tests and χ² tests were used to determine statistical significance (P<.05).

On average, matched applicants without HPs matched in lower-ranked (74.4) and smaller (12.4) programs compared with matched applicants with HPs (45.3 [P<.0001] and 15.1 [P<.0001], respectively)(eTable). The mean number of publications was similar between matched applicants with HPs and without HPs (5.64 and 4.80, respectively; P=.0525) as well as the percentage with ADs (14.7% and 11.5%, respectively; P=.0953). Overall, 14.8% of matched applicants without HPs matched at their mentors’ institutions.

Data were obtained for matched international applicants as a subset of non-HP applicants. Despite attending medical schools without associated HPs in the United States, international applicants matched at similarly ranked (44.3) and sized (15.0) programs, on average, compared with HP applicants. The mean number of publications was higher for international applicants (11.4) vs domestic applicants (5.33). International applicants more often had ADs (23.8%) and 60.1% of them held doctor of philosophy degrees. Overall, 40.5% of international applicants matched at their mentors’ institutions.

Our study suggests that matched dermatology applicants with and without HPs had similar achievements, on average, for the number of publications and percentage with ADs. However, non-HP applicants matched at lower-ranked programs than HP applicants. Therefore, applicants without HPs should strongly consider cultivating program connections, especially if they desire to match at higher-ranked dermatology programs. To illustrate, the rate of matching at research mentors’ institutions was approximately 3-times higher for international applicants than non-HP applicants overall. Despite the disadvantages of applying as international applicants, they were able to match at substantially higher-ranked dermatology programs than non-HP applicants. International applicants may have a longer time investment—the number of years from obtaining their medical degree or US medical license to matching—giving them time to produce quality research and develop meaningful relationships at an institution. Additionally, our prior study of the top 25 dermatology residencies showed that 26.2% of successful applicants matched at their research mentors’ institutions, with almost half of this subset matching at their HPs, where their mentors also practiced.² Because of the potential benefits of having program connections, applicants without HPs should seek dermatology research mentors, especially via highly beneficial in-person networking opportunities (eg, away rotations, conferences) that had previously been limited during the COVID-19 pandemic.³ Formal mentorship programs giving priority to students without HPs recently have been developed, which only begins to address the inequities in the dermatology residency application process.⁴

Study limitations include lack of resident information on 15 program websites, missed publications due to applicant name changes, not accounting for abstracts and posters, and inability to collect data on unmatched applicants.

We hope that our study alleviates some concerns that applicants without HPs may have regarding applying for dermatology residency and encourages those with a genuine interest in dermatology to pursue the specialty, provided they find a strong research mentor. Residency programs should be cognizant of the unique challenges that non-HP applicants face for matching.

To the Editor:

Dermatology is one of the most competitive residencies for matching, with a 57.5% match rate in 2022.¹ Our prior study of research-mentor relationships among matched dermatology applicants corroborated the importance of home programs (HPs) and program connections.² Therefore, our current objective was to compare profiles of matched dermatology applicants without HPs vs those with HPs.

We searched websites of 139 dermatology programs nationwide and found 1736 matched applicants from 2016 to 2020; of them, 323 did not have HPs. We determined program rank by research output using Doximity Residency Navigator (https://www.doximity.com/residency/). Advanced degrees (ADs) of applicants were identified using program websites and LinkedIn. A PubMed search was conducted for number of articles published by each applicant before September 15 of their match year. For applicants without HPs, we identified the senior author on each publication. The senior author publishing with an applicant most often was considered the research mentor. Two-tailed independent t tests and χ² tests were used to determine statistical significance (P<.05).

On average, matched applicants without HPs matched in lower-ranked (74.4) and smaller (12.4) programs compared with matched applicants with HPs (45.3 [P<.0001] and 15.1 [P<.0001], respectively)(eTable). The mean number of publications was similar between matched applicants with HPs and without HPs (5.64 and 4.80, respectively; P=.0525) as well as the percentage with ADs (14.7% and 11.5%, respectively; P=.0953). Overall, 14.8% of matched applicants without HPs matched at their mentors’ institutions.

Data were obtained for matched international applicants as a subset of non-HP applicants. Despite attending medical schools without associated HPs in the United States, international applicants matched at similarly ranked (44.3) and sized (15.0) programs, on average, compared with HP applicants. The mean number of publications was higher for international applicants (11.4) vs domestic applicants (5.33). International applicants more often had ADs (23.8%) and 60.1% of them held doctor of philosophy degrees. Overall, 40.5% of international applicants matched at their mentors’ institutions.

Our study suggests that matched dermatology applicants with and without HPs had similar achievements, on average, for the number of publications and percentage with ADs. However, non-HP applicants matched at lower-ranked programs than HP applicants. Therefore, applicants without HPs should strongly consider cultivating program connections, especially if they desire to match at higher-ranked dermatology programs. To illustrate, the rate of matching at research mentors’ institutions was approximately 3-times higher for international applicants than non-HP applicants overall. Despite the disadvantages of applying as international applicants, they were able to match at substantially higher-ranked dermatology programs than non-HP applicants. International applicants may have a longer time investment—the number of years from obtaining their medical degree or US medical license to matching—giving them time to produce quality research and develop meaningful relationships at an institution. Additionally, our prior study of the top 25 dermatology residencies showed that 26.2% of successful applicants matched at their research mentors’ institutions, with almost half of this subset matching at their HPs, where their mentors also practiced.² Because of the potential benefits of having program connections, applicants without HPs should seek dermatology research mentors, especially via highly beneficial in-person networking opportunities (eg, away rotations, conferences) that had previously been limited during the COVID-19 pandemic.³ Formal mentorship programs giving priority to students without HPs recently have been developed, which only begins to address the inequities in the dermatology residency application process.⁴

Study limitations include lack of resident information on 15 program websites, missed publications due to applicant name changes, not accounting for abstracts and posters, and inability to collect data on unmatched applicants.

We hope that our study alleviates some concerns that applicants without HPs may have regarding applying for dermatology residency and encourages those with a genuine interest in dermatology to pursue the specialty, provided they find a strong research mentor. Residency programs should be cognizant of the unique challenges that non-HP applicants face for matching.

Classification

Triatomine bugs (Triatoma) and the wheel bug (Arilus cristatus) are part of the family Reduviidae (order Hemiptera, a name that describes the sucking proboscis on the front of the insect’s head).^1,2 Both arthropods are found in multiple countries and are especially common in warmer areas, including in the United States, where they can be seen from Texas to California.^3,4 Because blood-feeding triatomines need a blood meal to survive while laying eggs and then throughout their 5 developmental nymph stages to undergo molting, they feed on mammals, such as opossums, raccoons, pack rats, and armadillos, whereas wheel bugs mainly prey on soft-bodied insects.^1,4-6

Triatoma bugs seek cutaneous blood vessels using thermosensors in their antennae to locate blood flow under the skin for feeding. After inserting the proboscis, they release nitric oxide and an anticoagulant that allows for continuous blood flow while feeding.⁷ It has been reported that triatomine bugs are not able to bite through clothing, instead seeking exposed skin, particularly near mucous membranes, such as the hands, arms, feet, head, and trunk. The name kissing bug for triatomines was coined because bites near the mouth are common.⁶ The bite typically is painless and occurs mainly at night when the insect is most active. After obtaining a blood meal, triatomine bugs seek shelter and hide in mud and daub structures, cracks, crevices, and furniture.^1,8

Unlike Triatoma species, A cristatus does not require a blood meal for development and survival, leading it to prey on soft-bodied insects. Piercing prey with the proboscis, wheel bugs inject a toxin to digest the contents and suck the digested contents through this apparatus.⁴ Because the wheel bug does not require a blood meal, it typically bites a human only for defense if it feels threatened. Unlike the painless bite of a triatomine bug, the bite of A cristatus is extremely painful; it has been described as the worst arthropod bite—worse than a hornet’s sting. The pain from the bite is caused by the toxin being injected into the skin; possible retention of the proboscis makes the pain worse.^4,9 In addition, when A cristatus is disturbed, it exudes pungent material from a pair of bright orange subrectal glands while stridulating to repulse predators.⁹

Although Triatoma species and A cristatus have separate roles in nature and vastly different impacts on health, they often are mistaken for the same arthropod when seen in nature. Features that members of Reduviidae share include large bodies (relative to their overall length); long thin legs; a narrow head; wings; and a long sucking proboscis on the front of the head.¹⁰

Characteristics that differentiate Triatoma and A cristatus species include size, color, and distinctive markings. Most triatomine bugs are 12- to 36-mm long; are dark brown or black; and have what are called tiger-stripe orange markings on the peripheral two-thirds of the body (Figure 1).¹¹ In contrast, wheel bugs commonly are bigger—measuring longer than 1.25 inches—and gray, with a cogwheel-like structure on the thorax (Figure 2).¹⁰

Dermatologic Presentation and Clinical Symptoms

The area of involved skin on patients presenting with Triatoma or A cristatus bites may resemble other insect bites. Many bites from Triatoma bugs and A cristatus initially present as an erythematous, raised, pruritic papule with a central punctum that is visible because of the involvement of the proboscis. However, other presentations of bites from both arthropods have been reported^4,6,7: grouped vesicles on an erythematous base; indurated, giant, urticarial-type wheels measuring 10 to 15 mm in diameter; and hemorrhagic bullous nodules (Figure 3). Associated lymphangitis or lymphadenitis is typical of the latter 2 variations.⁶ These variations in presentation can be mistaken for other causes of similarly presenting lesions, such as shingles or spider bites, leading to delayed or missed diagnosis.

Patients may present with a single bite or multiple bites due to the feeding pattern of Triatoma bugs; if the host moves or disrupts its feeding, the arthropod takes multiple bites to finish feeding.⁸ In comparison, 4 common variations of wheel bug bites have been reported: (1) a painful bite without complications; (2) a cutaneous horn and papilloma at the site of toxin injection; (3) a necrotic ulcer around the central punctum caused by injected toxin; and (4) an abscess under the central punctum due to secondary infection.⁴

Anaphylaxis—Although the bites of Triatoma and A cristatus present differently, both can cause anaphylaxis. Triatoma is implicated more often than A cristatus as the cause of anaphylaxis.¹² In fact, Triatoma bites are among the more common causes of anaphylaxis from bug bites, with multiple cases of these reactions reported in the literature.^12,13

Symptoms of Triatoma anaphylaxis include acute-onset urticarial rash, flushing, dyspnea, wheezing, nausea, vomiting, and localized edema.² The cause of anaphylaxis is proteins in Triatoma saliva, including 20-kDa procalin, which incites the systemic reaction. Other potential causes of anaphylaxis include serine protease, which has similarities to salivary protein and desmoglein in humans.¹¹

The degree of reaction to a bite depends on the patient's sensitization to antigenic proteins in each insect’s saliva.^4,6 Patients who have a bite from a triatomine bug are at risk for subsequent bites, as household infestation is likely due to the pliability of the insect, allowing it to hide in small spaces unnoticed.⁸ In the case of a bite from Triatoma or A cristatus, sensitization may lead to severe and worsening reactions with subsequent bites, which ultimately can result in life-threatening anaphylaxis.^1,6

Treatment and Prevention

Treatment of Triatoma and A cristatus bites depends on the severity of the patient’s reaction to the bite. A local reaction to a bite from either insect can be treated supportively with local corticosteroids and antihistamines.³ If the patient is sensitized to proteins associated with a bite, standard anaphylaxis treatment such as epinephrine and intravenous antihistamines may be indicated.¹⁴ Secondary infection can be treated with antibiotics; a formed abscess might need to be drained or debrided.¹⁵

There’s No Place Like Home—Because Triatoma bugs have a pliable exoskeleton and can squeeze into small spaces, they commonly infest dwellings where they find multiple attractants: light, heat, carbon dioxide, and lactic acid.⁸ The more household occupants (including pets), the higher the levels of carbon dioxide and lactic acid, thus the greater the attraction. Infestation of a home can lead to the spread of diseases harbored by Triatoma, including Chagas disease, which is caused by the parasite Trypanosoma cruzi.⁵

Preventive measures can be taken to reduce the risk and extent of home infestation by Triatoma bugs, including insecticides, a solid foundation, window screens, air conditioning, sealing of cracks and crevices, outdoor light management, and removal of clutter throughout the house.⁸ Because Triatoma bugs cannot bite through clothing, protective clothing and bug repellent on exposed skin can be employed. Another degree of protection is offered by pest management, especially control of rodents by removing food, water, and nests in areas where triatomine bugs feed off of that population.^8,14

Unlike triatomine bugs, wheel bugs tend not to invade houses; therefore, these preventive measures are unnecessary. If a wheel bug is identified, do not engage the arthropod due to the defensive nature of its attack.^4,9 Such deliberate avoidance should ensure protection from the wheel bug’s painful bite.

Medical Complications

Although triatomine bugs and wheel bugs are in the same taxonomic family, subsequent infection is unique to Triatoma bugs because they need a blood meal to survive. Because Triatoma bugs feed on mammals, they present an increased opportunity for transmitting the causative agents of infection from hosts on which they have fed.¹² The principal parasite transmitted by triatomines is T cruzi, which causes Chagas disease and lives in the gastrointestinal (GI) tract of the insect.⁵ When a triatomine bug seeks out a mucosal surface to bite, including the mouth, it defecates and urinates during or shortly after feeding, leading to contamination of the initial wound or mucosal surfaces. In addition, Triatoma bugs are vectors for transmission of Serratia marcescans, Bartonella henselae, and Mycobacterium leprae.¹⁶

Chagas Disease—This infection has 3 stages: acute, intermediate, and chronic.⁵ The acute stage can present with symptoms of conjunctivitis, fever, lymphadenopathy, hepatosplenomegaly, and anemia. The intermediate stage typically is asymptomatic. The chronic stage usually involves the heart and GI tract and causes cardiac aneurysms, cardiomegaly, megacolon, and megaesophagus. Initial symptoms can be a localized nodule (chagoma) at the inoculation site, fever, fatigue, lymphadenopathy, and hepatosplenomegaly.² Unilateral palpebral edema with associated lymphadenopathy (Romaña sign) also can be seen—not to be confused with bilateral swelling in an acute reaction to an insect bite. Romaña sign is pathognomonic of T cruzi infection; bilateral palpebral swelling is typical of an allergic reaction.¹²

Identification of a triatomine bite is the first step in diagnosing Chagas disease, which can be life-threatening. Among chronic carriers of Chagas disease, 30% develop GI and cardiac symptoms, of which 20% to 30% develop cardiomyopathy, with serious symptoms that present 10 to 20 years after the asymptomatic intermediate phase.²

Chagas disease is endemic to Central and South America but is also seen in North America; 28,000 new cases are reported annually in South America and North America combined. Human migration from endemic areas and from rural to urban areas has promoted the spread of Chagas disease.² However, patients in the United States have a relatively low risk for Chagas disease, largely because of the quality of housing construction and use of insecticides.

Treatment options for Chagas disease include nifurtimox and benznidazole. Without treatment, the host immune response typically controls acute replication of the parasite but will lead to a chronic state, ultimately involving the heart and GI tract.⁵

Classification

Triatomine bugs (Triatoma) and the wheel bug (Arilus cristatus) are part of the family Reduviidae (order Hemiptera, a name that describes the sucking proboscis on the front of the insect’s head).^1,2 Both arthropods are found in multiple countries and are especially common in warmer areas, including in the United States, where they can be seen from Texas to California.^3,4 Because blood-feeding triatomines need a blood meal to survive while laying eggs and then throughout their 5 developmental nymph stages to undergo molting, they feed on mammals, such as opossums, raccoons, pack rats, and armadillos, whereas wheel bugs mainly prey on soft-bodied insects.^1,4-6

Triatoma bugs seek cutaneous blood vessels using thermosensors in their antennae to locate blood flow under the skin for feeding. After inserting the proboscis, they release nitric oxide and an anticoagulant that allows for continuous blood flow while feeding.⁷ It has been reported that triatomine bugs are not able to bite through clothing, instead seeking exposed skin, particularly near mucous membranes, such as the hands, arms, feet, head, and trunk. The name kissing bug for triatomines was coined because bites near the mouth are common.⁶ The bite typically is painless and occurs mainly at night when the insect is most active. After obtaining a blood meal, triatomine bugs seek shelter and hide in mud and daub structures, cracks, crevices, and furniture.^1,8

Unlike Triatoma species, A cristatus does not require a blood meal for development and survival, leading it to prey on soft-bodied insects. Piercing prey with the proboscis, wheel bugs inject a toxin to digest the contents and suck the digested contents through this apparatus.⁴ Because the wheel bug does not require a blood meal, it typically bites a human only for defense if it feels threatened. Unlike the painless bite of a triatomine bug, the bite of A cristatus is extremely painful; it has been described as the worst arthropod bite—worse than a hornet’s sting. The pain from the bite is caused by the toxin being injected into the skin; possible retention of the proboscis makes the pain worse.^4,9 In addition, when A cristatus is disturbed, it exudes pungent material from a pair of bright orange subrectal glands while stridulating to repulse predators.⁹

Although Triatoma species and A cristatus have separate roles in nature and vastly different impacts on health, they often are mistaken for the same arthropod when seen in nature. Features that members of Reduviidae share include large bodies (relative to their overall length); long thin legs; a narrow head; wings; and a long sucking proboscis on the front of the head.¹⁰

Characteristics that differentiate Triatoma and A cristatus species include size, color, and distinctive markings. Most triatomine bugs are 12- to 36-mm long; are dark brown or black; and have what are called tiger-stripe orange markings on the peripheral two-thirds of the body (Figure 1).¹¹ In contrast, wheel bugs commonly are bigger—measuring longer than 1.25 inches—and gray, with a cogwheel-like structure on the thorax (Figure 2).¹⁰

Dermatologic Presentation and Clinical Symptoms

The area of involved skin on patients presenting with Triatoma or A cristatus bites may resemble other insect bites. Many bites from Triatoma bugs and A cristatus initially present as an erythematous, raised, pruritic papule with a central punctum that is visible because of the involvement of the proboscis. However, other presentations of bites from both arthropods have been reported^4,6,7: grouped vesicles on an erythematous base; indurated, giant, urticarial-type wheels measuring 10 to 15 mm in diameter; and hemorrhagic bullous nodules (Figure 3). Associated lymphangitis or lymphadenitis is typical of the latter 2 variations.⁶ These variations in presentation can be mistaken for other causes of similarly presenting lesions, such as shingles or spider bites, leading to delayed or missed diagnosis.

Patients may present with a single bite or multiple bites due to the feeding pattern of Triatoma bugs; if the host moves or disrupts its feeding, the arthropod takes multiple bites to finish feeding.⁸ In comparison, 4 common variations of wheel bug bites have been reported: (1) a painful bite without complications; (2) a cutaneous horn and papilloma at the site of toxin injection; (3) a necrotic ulcer around the central punctum caused by injected toxin; and (4) an abscess under the central punctum due to secondary infection.⁴

Anaphylaxis—Although the bites of Triatoma and A cristatus present differently, both can cause anaphylaxis. Triatoma is implicated more often than A cristatus as the cause of anaphylaxis.¹² In fact, Triatoma bites are among the more common causes of anaphylaxis from bug bites, with multiple cases of these reactions reported in the literature.^12,13

Symptoms of Triatoma anaphylaxis include acute-onset urticarial rash, flushing, dyspnea, wheezing, nausea, vomiting, and localized edema.² The cause of anaphylaxis is proteins in Triatoma saliva, including 20-kDa procalin, which incites the systemic reaction. Other potential causes of anaphylaxis include serine protease, which has similarities to salivary protein and desmoglein in humans.¹¹

The degree of reaction to a bite depends on the patient's sensitization to antigenic proteins in each insect’s saliva.^4,6 Patients who have a bite from a triatomine bug are at risk for subsequent bites, as household infestation is likely due to the pliability of the insect, allowing it to hide in small spaces unnoticed.⁸ In the case of a bite from Triatoma or A cristatus, sensitization may lead to severe and worsening reactions with subsequent bites, which ultimately can result in life-threatening anaphylaxis.^1,6

Treatment and Prevention

Treatment of Triatoma and A cristatus bites depends on the severity of the patient’s reaction to the bite. A local reaction to a bite from either insect can be treated supportively with local corticosteroids and antihistamines.³ If the patient is sensitized to proteins associated with a bite, standard anaphylaxis treatment such as epinephrine and intravenous antihistamines may be indicated.¹⁴ Secondary infection can be treated with antibiotics; a formed abscess might need to be drained or debrided.¹⁵

There’s No Place Like Home—Because Triatoma bugs have a pliable exoskeleton and can squeeze into small spaces, they commonly infest dwellings where they find multiple attractants: light, heat, carbon dioxide, and lactic acid.⁸ The more household occupants (including pets), the higher the levels of carbon dioxide and lactic acid, thus the greater the attraction. Infestation of a home can lead to the spread of diseases harbored by Triatoma, including Chagas disease, which is caused by the parasite Trypanosoma cruzi.⁵

Preventive measures can be taken to reduce the risk and extent of home infestation by Triatoma bugs, including insecticides, a solid foundation, window screens, air conditioning, sealing of cracks and crevices, outdoor light management, and removal of clutter throughout the house.⁸ Because Triatoma bugs cannot bite through clothing, protective clothing and bug repellent on exposed skin can be employed. Another degree of protection is offered by pest management, especially control of rodents by removing food, water, and nests in areas where triatomine bugs feed off of that population.^8,14

Unlike triatomine bugs, wheel bugs tend not to invade houses; therefore, these preventive measures are unnecessary. If a wheel bug is identified, do not engage the arthropod due to the defensive nature of its attack.^4,9 Such deliberate avoidance should ensure protection from the wheel bug’s painful bite.

Medical Complications

Although triatomine bugs and wheel bugs are in the same taxonomic family, subsequent infection is unique to Triatoma bugs because they need a blood meal to survive. Because Triatoma bugs feed on mammals, they present an increased opportunity for transmitting the causative agents of infection from hosts on which they have fed.¹² The principal parasite transmitted by triatomines is T cruzi, which causes Chagas disease and lives in the gastrointestinal (GI) tract of the insect.⁵ When a triatomine bug seeks out a mucosal surface to bite, including the mouth, it defecates and urinates during or shortly after feeding, leading to contamination of the initial wound or mucosal surfaces. In addition, Triatoma bugs are vectors for transmission of Serratia marcescans, Bartonella henselae, and Mycobacterium leprae.¹⁶

Chagas Disease—This infection has 3 stages: acute, intermediate, and chronic.⁵ The acute stage can present with symptoms of conjunctivitis, fever, lymphadenopathy, hepatosplenomegaly, and anemia. The intermediate stage typically is asymptomatic. The chronic stage usually involves the heart and GI tract and causes cardiac aneurysms, cardiomegaly, megacolon, and megaesophagus. Initial symptoms can be a localized nodule (chagoma) at the inoculation site, fever, fatigue, lymphadenopathy, and hepatosplenomegaly.² Unilateral palpebral edema with associated lymphadenopathy (Romaña sign) also can be seen—not to be confused with bilateral swelling in an acute reaction to an insect bite. Romaña sign is pathognomonic of T cruzi infection; bilateral palpebral swelling is typical of an allergic reaction.¹²

Identification of a triatomine bite is the first step in diagnosing Chagas disease, which can be life-threatening. Among chronic carriers of Chagas disease, 30% develop GI and cardiac symptoms, of which 20% to 30% develop cardiomyopathy, with serious symptoms that present 10 to 20 years after the asymptomatic intermediate phase.²

Chagas disease is endemic to Central and South America but is also seen in North America; 28,000 new cases are reported annually in South America and North America combined. Human migration from endemic areas and from rural to urban areas has promoted the spread of Chagas disease.² However, patients in the United States have a relatively low risk for Chagas disease, largely because of the quality of housing construction and use of insecticides.

Treatment options for Chagas disease include nifurtimox and benznidazole. Without treatment, the host immune response typically controls acute replication of the parasite but will lead to a chronic state, ultimately involving the heart and GI tract.⁵

Classification

Triatomine bugs (Triatoma) and the wheel bug (Arilus cristatus) are part of the family Reduviidae (order Hemiptera, a name that describes the sucking proboscis on the front of the insect’s head).^1,2 Both arthropods are found in multiple countries and are especially common in warmer areas, including in the United States, where they can be seen from Texas to California.^3,4 Because blood-feeding triatomines need a blood meal to survive while laying eggs and then throughout their 5 developmental nymph stages to undergo molting, they feed on mammals, such as opossums, raccoons, pack rats, and armadillos, whereas wheel bugs mainly prey on soft-bodied insects.^1,4-6

Triatoma bugs seek cutaneous blood vessels using thermosensors in their antennae to locate blood flow under the skin for feeding. After inserting the proboscis, they release nitric oxide and an anticoagulant that allows for continuous blood flow while feeding.⁷ It has been reported that triatomine bugs are not able to bite through clothing, instead seeking exposed skin, particularly near mucous membranes, such as the hands, arms, feet, head, and trunk. The name kissing bug for triatomines was coined because bites near the mouth are common.⁶ The bite typically is painless and occurs mainly at night when the insect is most active. After obtaining a blood meal, triatomine bugs seek shelter and hide in mud and daub structures, cracks, crevices, and furniture.^1,8

Unlike Triatoma species, A cristatus does not require a blood meal for development and survival, leading it to prey on soft-bodied insects. Piercing prey with the proboscis, wheel bugs inject a toxin to digest the contents and suck the digested contents through this apparatus.⁴ Because the wheel bug does not require a blood meal, it typically bites a human only for defense if it feels threatened. Unlike the painless bite of a triatomine bug, the bite of A cristatus is extremely painful; it has been described as the worst arthropod bite—worse than a hornet’s sting. The pain from the bite is caused by the toxin being injected into the skin; possible retention of the proboscis makes the pain worse.^4,9 In addition, when A cristatus is disturbed, it exudes pungent material from a pair of bright orange subrectal glands while stridulating to repulse predators.⁹

Although Triatoma species and A cristatus have separate roles in nature and vastly different impacts on health, they often are mistaken for the same arthropod when seen in nature. Features that members of Reduviidae share include large bodies (relative to their overall length); long thin legs; a narrow head; wings; and a long sucking proboscis on the front of the head.¹⁰

Characteristics that differentiate Triatoma and A cristatus species include size, color, and distinctive markings. Most triatomine bugs are 12- to 36-mm long; are dark brown or black; and have what are called tiger-stripe orange markings on the peripheral two-thirds of the body (Figure 1).¹¹ In contrast, wheel bugs commonly are bigger—measuring longer than 1.25 inches—and gray, with a cogwheel-like structure on the thorax (Figure 2).¹⁰

Dermatologic Presentation and Clinical Symptoms

The area of involved skin on patients presenting with Triatoma or A cristatus bites may resemble other insect bites. Many bites from Triatoma bugs and A cristatus initially present as an erythematous, raised, pruritic papule with a central punctum that is visible because of the involvement of the proboscis. However, other presentations of bites from both arthropods have been reported^4,6,7: grouped vesicles on an erythematous base; indurated, giant, urticarial-type wheels measuring 10 to 15 mm in diameter; and hemorrhagic bullous nodules (Figure 3). Associated lymphangitis or lymphadenitis is typical of the latter 2 variations.⁶ These variations in presentation can be mistaken for other causes of similarly presenting lesions, such as shingles or spider bites, leading to delayed or missed diagnosis.

Patients may present with a single bite or multiple bites due to the feeding pattern of Triatoma bugs; if the host moves or disrupts its feeding, the arthropod takes multiple bites to finish feeding.⁸ In comparison, 4 common variations of wheel bug bites have been reported: (1) a painful bite without complications; (2) a cutaneous horn and papilloma at the site of toxin injection; (3) a necrotic ulcer around the central punctum caused by injected toxin; and (4) an abscess under the central punctum due to secondary infection.⁴

Anaphylaxis—Although the bites of Triatoma and A cristatus present differently, both can cause anaphylaxis. Triatoma is implicated more often than A cristatus as the cause of anaphylaxis.¹² In fact, Triatoma bites are among the more common causes of anaphylaxis from bug bites, with multiple cases of these reactions reported in the literature.^12,13

Symptoms of Triatoma anaphylaxis include acute-onset urticarial rash, flushing, dyspnea, wheezing, nausea, vomiting, and localized edema.² The cause of anaphylaxis is proteins in Triatoma saliva, including 20-kDa procalin, which incites the systemic reaction. Other potential causes of anaphylaxis include serine protease, which has similarities to salivary protein and desmoglein in humans.¹¹

The degree of reaction to a bite depends on the patient's sensitization to antigenic proteins in each insect’s saliva.^4,6 Patients who have a bite from a triatomine bug are at risk for subsequent bites, as household infestation is likely due to the pliability of the insect, allowing it to hide in small spaces unnoticed.⁸ In the case of a bite from Triatoma or A cristatus, sensitization may lead to severe and worsening reactions with subsequent bites, which ultimately can result in life-threatening anaphylaxis.^1,6

Treatment and Prevention

Treatment of Triatoma and A cristatus bites depends on the severity of the patient’s reaction to the bite. A local reaction to a bite from either insect can be treated supportively with local corticosteroids and antihistamines.³ If the patient is sensitized to proteins associated with a bite, standard anaphylaxis treatment such as epinephrine and intravenous antihistamines may be indicated.¹⁴ Secondary infection can be treated with antibiotics; a formed abscess might need to be drained or debrided.¹⁵

There’s No Place Like Home—Because Triatoma bugs have a pliable exoskeleton and can squeeze into small spaces, they commonly infest dwellings where they find multiple attractants: light, heat, carbon dioxide, and lactic acid.⁸ The more household occupants (including pets), the higher the levels of carbon dioxide and lactic acid, thus the greater the attraction. Infestation of a home can lead to the spread of diseases harbored by Triatoma, including Chagas disease, which is caused by the parasite Trypanosoma cruzi.⁵

Preventive measures can be taken to reduce the risk and extent of home infestation by Triatoma bugs, including insecticides, a solid foundation, window screens, air conditioning, sealing of cracks and crevices, outdoor light management, and removal of clutter throughout the house.⁸ Because Triatoma bugs cannot bite through clothing, protective clothing and bug repellent on exposed skin can be employed. Another degree of protection is offered by pest management, especially control of rodents by removing food, water, and nests in areas where triatomine bugs feed off of that population.^8,14

Unlike triatomine bugs, wheel bugs tend not to invade houses; therefore, these preventive measures are unnecessary. If a wheel bug is identified, do not engage the arthropod due to the defensive nature of its attack.^4,9 Such deliberate avoidance should ensure protection from the wheel bug’s painful bite.

Medical Complications

Although triatomine bugs and wheel bugs are in the same taxonomic family, subsequent infection is unique to Triatoma bugs because they need a blood meal to survive. Because Triatoma bugs feed on mammals, they present an increased opportunity for transmitting the causative agents of infection from hosts on which they have fed.¹² The principal parasite transmitted by triatomines is T cruzi, which causes Chagas disease and lives in the gastrointestinal (GI) tract of the insect.⁵ When a triatomine bug seeks out a mucosal surface to bite, including the mouth, it defecates and urinates during or shortly after feeding, leading to contamination of the initial wound or mucosal surfaces. In addition, Triatoma bugs are vectors for transmission of Serratia marcescans, Bartonella henselae, and Mycobacterium leprae.¹⁶

Chagas Disease—This infection has 3 stages: acute, intermediate, and chronic.⁵ The acute stage can present with symptoms of conjunctivitis, fever, lymphadenopathy, hepatosplenomegaly, and anemia. The intermediate stage typically is asymptomatic. The chronic stage usually involves the heart and GI tract and causes cardiac aneurysms, cardiomegaly, megacolon, and megaesophagus. Initial symptoms can be a localized nodule (chagoma) at the inoculation site, fever, fatigue, lymphadenopathy, and hepatosplenomegaly.² Unilateral palpebral edema with associated lymphadenopathy (Romaña sign) also can be seen—not to be confused with bilateral swelling in an acute reaction to an insect bite. Romaña sign is pathognomonic of T cruzi infection; bilateral palpebral swelling is typical of an allergic reaction.¹²

Identification of a triatomine bite is the first step in diagnosing Chagas disease, which can be life-threatening. Among chronic carriers of Chagas disease, 30% develop GI and cardiac symptoms, of which 20% to 30% develop cardiomyopathy, with serious symptoms that present 10 to 20 years after the asymptomatic intermediate phase.²

Chagas disease is endemic to Central and South America but is also seen in North America; 28,000 new cases are reported annually in South America and North America combined. Human migration from endemic areas and from rural to urban areas has promoted the spread of Chagas disease.² However, patients in the United States have a relatively low risk for Chagas disease, largely because of the quality of housing construction and use of insecticides.

Treatment options for Chagas disease include nifurtimox and benznidazole. Without treatment, the host immune response typically controls acute replication of the parasite but will lead to a chronic state, ultimately involving the heart and GI tract.⁵

When the Current Procedural Terminology (CPT) evaluation and management (E/M) reporting rules changed dramatically in January 2021, “bullet counting” became unnecessary and the coding level became based on either the new medical decision making (MDM) table or time spent on all activities relating to the care of the patient on the day of the encounter. ¹

To make your documentation more likely to pass audits, explicitly link parts of your documentation to CPT MDM descriptors. Part 1 of this series discussed how to approach the “spot check,” a commonly encountered chief concern (CC) within dermatology, with 2 scenarios presented.² The American Medical Association³ and American Academy of Dermatology⁴ have provided education that focuses on how to report a given vignette, but specific examples of documentation with commentary are uncommon. In part 2, we describe how to best code an encounter that includes a “spot check” with other concerns.

Scenario 3: By the Way, Doc

A 34-year-old presents with a new spot on the left cheek that seems to be growing and changing shape rapidly. You examine the patient and discuss treatment options. The documentation reads as follows:

• CC: New spot on left cheek that seems to be growing and changing shape rapidly.
• History: No family history of skin cancer; concerned about scarring, no blood thinner.
• Examination: Irregular tan to brown to black 8-mm macule. No lymphadenopathy.
• Impression: Rule out melanoma (undiagnosed new problem with uncertain prognosis).
• Plan: Discuss risks, benefits, and alternatives, including biopsy (decision regarding minor surgery with identified patient or procedure risk factors) vs a noninvasive gene expression profiling (GEP) melanoma rule-out test. (Based on the decision you and the patient make, you also would document which option was chosen, so a biopsy would include your standard documentation, and if the GEP is chosen, you would simply state that this was chosen and performed.)

As you turn to leave the room, the patient says:“By the way, Doc, can you do anything about these silvery spots on my elbows, knees, and buttocks?” You look at the areas of concern and diagnose the patient with psoriasis.

How would it be best to approach this scenario? It depends on which treatment option the patient chooses.

If you performed a noninvasive GEP melanoma rule-out test, the CPT reporting does not change with the addition of the new problem, and only the codes 99204 (new patient office or other outpatient visit) or 99214 (established patient office or other outpatient visit) would be reported. This would be because, with the original documentation, the number and complexity of problems would be an “undiagnosed new problem with uncertain prognosis,” which would be moderate complexity (column 1, level 4). There are no data that are reviewed or analyzed, which would be straightforward (column 2, level 2). For risk, the discussion of the biopsy as a diagnostic choice should include possible scarring, bleeding, pain, and infection, which would be best described as a decision regarding minor surgery with identified patient or procedure risk factors, given the identified patient concerns, making this of moderate complexity (column 3, level 4).¹

Importantly, even if the procedure is not chosen as the final treatment plan, the discussion regarding the surgery, including the risks, benefits, and alternatives, can still count toward this category in the MDM table. Therefore, in this scenario, documentation would best fit with CPT code 99204 for a new patient or 99214 for an established patient. The addition of the psoriasis diagnosis would not change the level of service but also should include documentation of the psoriasis as medically necessary.

However, if you perform the biopsy, then the documentation above would only allow reporting the biopsy, as the decision to perform a 0- or 10-day global procedure is “bundled” with the procedure if performed on the same date of service. Therefore, with the addition of the psoriasis diagnosis, you would now use a separate E/M code to report the psoriasis. You must append a modifier −25 to the E/M code to certify that you are dealing with a separate and discrete problem with no overlap in physician work.

Clearly you also have an E/M to report. But what level? Is this chronic? Yes, as CPT clearly defines chronic as “[a] problem with an expected duration of at least one year or until the death of the patient.”^1,5

But is this stable progressive or showing side effects of treatment? “‘Stable’ for the purposes of categorizing MDM is defined by the specific treatment goals for an individual patient. A patient who is not at his or her treatment goal is not stable, even if the condition has not changed and there is no short-term threat to life or function,” according to the CPT descriptors. Therefore, in this scenario, the documentation would best fit a chronic illness with exacerbation, progression, or side effects of treatment (column 1, level 4), which is of moderate complexity.¹

But what about column 3, where we look at risks of testing and treatment? This would depend on the type of treatment given. If an over-the-counter product such as a tar gel is recommended, this is a low risk (column 3, level 3), which would mean this lower value determines the E/M code to be 99213 or 99203 depending on whether this is an established or new patient, respectively. If we treat with a prescription medication such as a topical corticosteroid, we are providing prescription drug management (column 3, level 4), which is moderate risk, and we would use codes 99204 or 99214, assuming we document appropriately. Again, including the CPT terminology of “not at treatment goal” in your impression and “prescription drug management” in your plan tells an auditor what you are thinking and doing.^1,5

The Takeaway—Clearly if a GEP is performed, there is a single CPT code used—99204 or 99214. If the biopsy is performed, there would be a biopsy code and an E/M code with a modifier −25 attached to the latter. For the documentation below, a 99204 or 99214 would be the chosen E/M code:

• CC: (1) New spot on left cheek that seems to be growing and changing shape rapidly; (2) Silvery spots on elbows, knees, and buttocks for which patient desires treatment.
• History: No family history of skin cancer; concerned about scarring, no blood thinner. Mom has psoriasis. Tried petroleum jelly on scaly areas but no better.
• Examination: Irregular tan to brown to black 8-mm macule. No lymphadenopathy. Silver scaly erythematous plaques on elbows, knees, sacrum.
• Impression: (1) Rule out melanoma (undiagnosed new problem with uncertain prognosis); (2) Psoriasis (chronic disease not at treatment goal).
• Plan: (1) Discuss risks, benefits, and alternatives, including biopsy (decision regarding minor surgery with identified patient or procedure risk factors) vs a noninvasive GEP melanoma rule-out test. Patient wants biopsy. Consent, biopsy via shave technique. Lidocaine hydrochloride 1% with epinephrine 1 cc, prepare and drape, aluminum chloride for hemostasis, ointment and bandage applied, care instructions provided; (2) Discuss options. Calcipotriene cream daily; triamcinolone ointment 0.1% twice a day (prescription drug management). Review bathing, avoiding trauma to site, no picking.

Scenario 4: Here for a Total-Body Screening Examination

Medicare does not cover skin cancer screenings as a primary CC. Being worried or knowing someone with melanoma are not CCs that are covered. However, “spot of concern,” “changing mole,” or ”new growth” would be. Conversely, if the patient has a history of skin cancer, actinic keratoses, or other premalignant lesions, and/or is immunosuppressed or has a high-risk genetic syndrome, the visit may be covered if these factors are documented in the note.⁶

For the diagnosis, the International Classification of Diseases, Tenth Revision, code Z12.83—“encounter for screening for malignant neoplasm of skin”—is not an appropriate primary billing code. However, D48.5—“neoplasm of behavior of skin”—can be, unless there is a specific diagnosis you are able to make (eg, melanocytic nevus, seborrheic keratosis).⁶

Let’s look at documentation examples:

• CC: 1-year follow-up on basal cell carcinoma (BCC) excision and concern about a new spot on the nose.
• History: Notice new spot on the nose; due for annual follow-up and came early for nose lesion.
• Examination: Left ala with flesh-colored papule dermoscopically banal. Prior left back BCC excision site soft and supple. Total-body examination performed, except perianal and external genitalia, and is unremarkable.
• Impression: Fibrous papule of nose and prior BCC treatment site with no sign of recurrence.
• Plan: Reassure. Annual surveillance in 1 year.

Using what we have previously discussed, this would likely be considered CPT code 99212 (established patient office visit). However, it is important to ensure all concerns and treatment interventions are fully documented. Consider this fuller documentation with bolded additions:

• CC: 1-year follow-up on BCC excision and concern about a new spot on the nose.
• History: Notice new spot on the nose; due for annual follow-up and came early for nose lesion. Also unhappy with generally looking older.
• Examination: Left ala with flesh-colored papule dermoscopically banal. Prior left back BCC excision site soft and supple. Diffuse changes of chronic sun damage. Total-body examination performed, except perianal and external genitalia, and is unremarkable.
• Impression: Fibrous papule of nose and prior BCC treatment site with no sign of recurrence and heliodermatosis/chronic sun damage not at treat-ment goal.
• Plan: Reassure. Annual surveillance in 1 year. Over-the-counter broad-spectrum sun protection factor 30+ sunscreen daily.

This is better but still possibly confusing to an auditor. Consider instead with bolded additions to the changes to the impression:

• CC: 1-year follow-up on BCC excision and concern about a new spot on the nose.
• History: Notice new spot on the nose; due for annual follow-up and came early for nose lesion. Also unhappy with generally looking older.
• Examination: Left ala with flesh-colored papule dermoscopically banal. Prior left back BCC excision site soft and supple. Diffuse changes of chronic sun damage. Total-body examination performed, except perianal and external genitalia, and is unremarkable.
• Impression: Fibrous papule of nose (D22.39)⁷ and prior BCC treatment site with no sign of recurrence (Z85.828: “personal history of other malignant neoplasm of skin) and heliodermatosis/chronic sun damage not at treatment goal (L57.8: “other skin changes due to chronic exposure to nonionizing radiation”).
• Plan: Reassure. Annual surveillance 1 year. Over-the-counter broad-spectrum sun protection factor 30+ sunscreen daily.

We now have chronic heliodermatitis not at treatment goal, which is moderate (column 1, level 4), and the over-the-counter broad-spectrum sun protection factor 30+ sunscreen (column 1, low) would be best coded as CPT code 99213.

Final Thoughts

“Spot check” encounters are common dermatologic visits, both on their own and in combination with other concerns. With the updated E/M guidelines, it is crucial to clarify and streamline your documentation. In particular, utilize language clearly defining the number and complexity of problems, data to be reviewed and/or analyzed, and appropriate risk stratification to ensure appropriate reimbursement and minimize your difficulties with audits.

When the Current Procedural Terminology (CPT) evaluation and management (E/M) reporting rules changed dramatically in January 2021, “bullet counting” became unnecessary and the coding level became based on either the new medical decision making (MDM) table or time spent on all activities relating to the care of the patient on the day of the encounter. ¹

To make your documentation more likely to pass audits, explicitly link parts of your documentation to CPT MDM descriptors. Part 1 of this series discussed how to approach the “spot check,” a commonly encountered chief concern (CC) within dermatology, with 2 scenarios presented.² The American Medical Association³ and American Academy of Dermatology⁴ have provided education that focuses on how to report a given vignette, but specific examples of documentation with commentary are uncommon. In part 2, we describe how to best code an encounter that includes a “spot check” with other concerns.

Scenario 3: By the Way, Doc

A 34-year-old presents with a new spot on the left cheek that seems to be growing and changing shape rapidly. You examine the patient and discuss treatment options. The documentation reads as follows:

• CC: New spot on left cheek that seems to be growing and changing shape rapidly.
• History: No family history of skin cancer; concerned about scarring, no blood thinner.
• Examination: Irregular tan to brown to black 8-mm macule. No lymphadenopathy.
• Impression: Rule out melanoma (undiagnosed new problem with uncertain prognosis).
• Plan: Discuss risks, benefits, and alternatives, including biopsy (decision regarding minor surgery with identified patient or procedure risk factors) vs a noninvasive gene expression profiling (GEP) melanoma rule-out test. (Based on the decision you and the patient make, you also would document which option was chosen, so a biopsy would include your standard documentation, and if the GEP is chosen, you would simply state that this was chosen and performed.)

As you turn to leave the room, the patient says:“By the way, Doc, can you do anything about these silvery spots on my elbows, knees, and buttocks?” You look at the areas of concern and diagnose the patient with psoriasis.

How would it be best to approach this scenario? It depends on which treatment option the patient chooses.

If you performed a noninvasive GEP melanoma rule-out test, the CPT reporting does not change with the addition of the new problem, and only the codes 99204 (new patient office or other outpatient visit) or 99214 (established patient office or other outpatient visit) would be reported. This would be because, with the original documentation, the number and complexity of problems would be an “undiagnosed new problem with uncertain prognosis,” which would be moderate complexity (column 1, level 4). There are no data that are reviewed or analyzed, which would be straightforward (column 2, level 2). For risk, the discussion of the biopsy as a diagnostic choice should include possible scarring, bleeding, pain, and infection, which would be best described as a decision regarding minor surgery with identified patient or procedure risk factors, given the identified patient concerns, making this of moderate complexity (column 3, level 4).¹

Importantly, even if the procedure is not chosen as the final treatment plan, the discussion regarding the surgery, including the risks, benefits, and alternatives, can still count toward this category in the MDM table. Therefore, in this scenario, documentation would best fit with CPT code 99204 for a new patient or 99214 for an established patient. The addition of the psoriasis diagnosis would not change the level of service but also should include documentation of the psoriasis as medically necessary.

However, if you perform the biopsy, then the documentation above would only allow reporting the biopsy, as the decision to perform a 0- or 10-day global procedure is “bundled” with the procedure if performed on the same date of service. Therefore, with the addition of the psoriasis diagnosis, you would now use a separate E/M code to report the psoriasis. You must append a modifier −25 to the E/M code to certify that you are dealing with a separate and discrete problem with no overlap in physician work.

Clearly you also have an E/M to report. But what level? Is this chronic? Yes, as CPT clearly defines chronic as “[a] problem with an expected duration of at least one year or until the death of the patient.”^1,5

But is this stable progressive or showing side effects of treatment? “‘Stable’ for the purposes of categorizing MDM is defined by the specific treatment goals for an individual patient. A patient who is not at his or her treatment goal is not stable, even if the condition has not changed and there is no short-term threat to life or function,” according to the CPT descriptors. Therefore, in this scenario, the documentation would best fit a chronic illness with exacerbation, progression, or side effects of treatment (column 1, level 4), which is of moderate complexity.¹

But what about column 3, where we look at risks of testing and treatment? This would depend on the type of treatment given. If an over-the-counter product such as a tar gel is recommended, this is a low risk (column 3, level 3), which would mean this lower value determines the E/M code to be 99213 or 99203 depending on whether this is an established or new patient, respectively. If we treat with a prescription medication such as a topical corticosteroid, we are providing prescription drug management (column 3, level 4), which is moderate risk, and we would use codes 99204 or 99214, assuming we document appropriately. Again, including the CPT terminology of “not at treatment goal” in your impression and “prescription drug management” in your plan tells an auditor what you are thinking and doing.^1,5

The Takeaway—Clearly if a GEP is performed, there is a single CPT code used—99204 or 99214. If the biopsy is performed, there would be a biopsy code and an E/M code with a modifier −25 attached to the latter. For the documentation below, a 99204 or 99214 would be the chosen E/M code:

• CC: (1) New spot on left cheek that seems to be growing and changing shape rapidly; (2) Silvery spots on elbows, knees, and buttocks for which patient desires treatment.
• History: No family history of skin cancer; concerned about scarring, no blood thinner. Mom has psoriasis. Tried petroleum jelly on scaly areas but no better.
• Examination: Irregular tan to brown to black 8-mm macule. No lymphadenopathy. Silver scaly erythematous plaques on elbows, knees, sacrum.
• Impression: (1) Rule out melanoma (undiagnosed new problem with uncertain prognosis); (2) Psoriasis (chronic disease not at treatment goal).
• Plan: (1) Discuss risks, benefits, and alternatives, including biopsy (decision regarding minor surgery with identified patient or procedure risk factors) vs a noninvasive GEP melanoma rule-out test. Patient wants biopsy. Consent, biopsy via shave technique. Lidocaine hydrochloride 1% with epinephrine 1 cc, prepare and drape, aluminum chloride for hemostasis, ointment and bandage applied, care instructions provided; (2) Discuss options. Calcipotriene cream daily; triamcinolone ointment 0.1% twice a day (prescription drug management). Review bathing, avoiding trauma to site, no picking.

Scenario 4: Here for a Total-Body Screening Examination

Medicare does not cover skin cancer screenings as a primary CC. Being worried or knowing someone with melanoma are not CCs that are covered. However, “spot of concern,” “changing mole,” or ”new growth” would be. Conversely, if the patient has a history of skin cancer, actinic keratoses, or other premalignant lesions, and/or is immunosuppressed or has a high-risk genetic syndrome, the visit may be covered if these factors are documented in the note.⁶

For the diagnosis, the International Classification of Diseases, Tenth Revision, code Z12.83—“encounter for screening for malignant neoplasm of skin”—is not an appropriate primary billing code. However, D48.5—“neoplasm of behavior of skin”—can be, unless there is a specific diagnosis you are able to make (eg, melanocytic nevus, seborrheic keratosis).⁶

Let’s look at documentation examples:

• CC: 1-year follow-up on basal cell carcinoma (BCC) excision and concern about a new spot on the nose.
• History: Notice new spot on the nose; due for annual follow-up and came early for nose lesion.
• Examination: Left ala with flesh-colored papule dermoscopically banal. Prior left back BCC excision site soft and supple. Total-body examination performed, except perianal and external genitalia, and is unremarkable.
• Impression: Fibrous papule of nose and prior BCC treatment site with no sign of recurrence.
• Plan: Reassure. Annual surveillance in 1 year.

Using what we have previously discussed, this would likely be considered CPT code 99212 (established patient office visit). However, it is important to ensure all concerns and treatment interventions are fully documented. Consider this fuller documentation with bolded additions:

• CC: 1-year follow-up on BCC excision and concern about a new spot on the nose.
• History: Notice new spot on the nose; due for annual follow-up and came early for nose lesion. Also unhappy with generally looking older.
• Examination: Left ala with flesh-colored papule dermoscopically banal. Prior left back BCC excision site soft and supple. Diffuse changes of chronic sun damage. Total-body examination performed, except perianal and external genitalia, and is unremarkable.
• Impression: Fibrous papule of nose and prior BCC treatment site with no sign of recurrence and heliodermatosis/chronic sun damage not at treat-ment goal.
• Plan: Reassure. Annual surveillance in 1 year. Over-the-counter broad-spectrum sun protection factor 30+ sunscreen daily.

This is better but still possibly confusing to an auditor. Consider instead with bolded additions to the changes to the impression:

• CC: 1-year follow-up on BCC excision and concern about a new spot on the nose.
• History: Notice new spot on the nose; due for annual follow-up and came early for nose lesion. Also unhappy with generally looking older.
• Examination: Left ala with flesh-colored papule dermoscopically banal. Prior left back BCC excision site soft and supple. Diffuse changes of chronic sun damage. Total-body examination performed, except perianal and external genitalia, and is unremarkable.
• Impression: Fibrous papule of nose (D22.39)⁷ and prior BCC treatment site with no sign of recurrence (Z85.828: “personal history of other malignant neoplasm of skin) and heliodermatosis/chronic sun damage not at treatment goal (L57.8: “other skin changes due to chronic exposure to nonionizing radiation”).
• Plan: Reassure. Annual surveillance 1 year. Over-the-counter broad-spectrum sun protection factor 30+ sunscreen daily.

We now have chronic heliodermatitis not at treatment goal, which is moderate (column 1, level 4), and the over-the-counter broad-spectrum sun protection factor 30+ sunscreen (column 1, low) would be best coded as CPT code 99213.

Final Thoughts

“Spot check” encounters are common dermatologic visits, both on their own and in combination with other concerns. With the updated E/M guidelines, it is crucial to clarify and streamline your documentation. In particular, utilize language clearly defining the number and complexity of problems, data to be reviewed and/or analyzed, and appropriate risk stratification to ensure appropriate reimbursement and minimize your difficulties with audits.

When the Current Procedural Terminology (CPT) evaluation and management (E/M) reporting rules changed dramatically in January 2021, “bullet counting” became unnecessary and the coding level became based on either the new medical decision making (MDM) table or time spent on all activities relating to the care of the patient on the day of the encounter. ¹

To make your documentation more likely to pass audits, explicitly link parts of your documentation to CPT MDM descriptors. Part 1 of this series discussed how to approach the “spot check,” a commonly encountered chief concern (CC) within dermatology, with 2 scenarios presented.² The American Medical Association³ and American Academy of Dermatology⁴ have provided education that focuses on how to report a given vignette, but specific examples of documentation with commentary are uncommon. In part 2, we describe how to best code an encounter that includes a “spot check” with other concerns.

Scenario 3: By the Way, Doc

A 34-year-old presents with a new spot on the left cheek that seems to be growing and changing shape rapidly. You examine the patient and discuss treatment options. The documentation reads as follows:

• CC: New spot on left cheek that seems to be growing and changing shape rapidly.
• History: No family history of skin cancer; concerned about scarring, no blood thinner.
• Examination: Irregular tan to brown to black 8-mm macule. No lymphadenopathy.
• Impression: Rule out melanoma (undiagnosed new problem with uncertain prognosis).
• Plan: Discuss risks, benefits, and alternatives, including biopsy (decision regarding minor surgery with identified patient or procedure risk factors) vs a noninvasive gene expression profiling (GEP) melanoma rule-out test. (Based on the decision you and the patient make, you also would document which option was chosen, so a biopsy would include your standard documentation, and if the GEP is chosen, you would simply state that this was chosen and performed.)

As you turn to leave the room, the patient says:“By the way, Doc, can you do anything about these silvery spots on my elbows, knees, and buttocks?” You look at the areas of concern and diagnose the patient with psoriasis.

How would it be best to approach this scenario? It depends on which treatment option the patient chooses.

If you performed a noninvasive GEP melanoma rule-out test, the CPT reporting does not change with the addition of the new problem, and only the codes 99204 (new patient office or other outpatient visit) or 99214 (established patient office or other outpatient visit) would be reported. This would be because, with the original documentation, the number and complexity of problems would be an “undiagnosed new problem with uncertain prognosis,” which would be moderate complexity (column 1, level 4). There are no data that are reviewed or analyzed, which would be straightforward (column 2, level 2). For risk, the discussion of the biopsy as a diagnostic choice should include possible scarring, bleeding, pain, and infection, which would be best described as a decision regarding minor surgery with identified patient or procedure risk factors, given the identified patient concerns, making this of moderate complexity (column 3, level 4).¹

Importantly, even if the procedure is not chosen as the final treatment plan, the discussion regarding the surgery, including the risks, benefits, and alternatives, can still count toward this category in the MDM table. Therefore, in this scenario, documentation would best fit with CPT code 99204 for a new patient or 99214 for an established patient. The addition of the psoriasis diagnosis would not change the level of service but also should include documentation of the psoriasis as medically necessary.

However, if you perform the biopsy, then the documentation above would only allow reporting the biopsy, as the decision to perform a 0- or 10-day global procedure is “bundled” with the procedure if performed on the same date of service. Therefore, with the addition of the psoriasis diagnosis, you would now use a separate E/M code to report the psoriasis. You must append a modifier −25 to the E/M code to certify that you are dealing with a separate and discrete problem with no overlap in physician work.

Clearly you also have an E/M to report. But what level? Is this chronic? Yes, as CPT clearly defines chronic as “[a] problem with an expected duration of at least one year or until the death of the patient.”^1,5

But is this stable progressive or showing side effects of treatment? “‘Stable’ for the purposes of categorizing MDM is defined by the specific treatment goals for an individual patient. A patient who is not at his or her treatment goal is not stable, even if the condition has not changed and there is no short-term threat to life or function,” according to the CPT descriptors. Therefore, in this scenario, the documentation would best fit a chronic illness with exacerbation, progression, or side effects of treatment (column 1, level 4), which is of moderate complexity.¹

But what about column 3, where we look at risks of testing and treatment? This would depend on the type of treatment given. If an over-the-counter product such as a tar gel is recommended, this is a low risk (column 3, level 3), which would mean this lower value determines the E/M code to be 99213 or 99203 depending on whether this is an established or new patient, respectively. If we treat with a prescription medication such as a topical corticosteroid, we are providing prescription drug management (column 3, level 4), which is moderate risk, and we would use codes 99204 or 99214, assuming we document appropriately. Again, including the CPT terminology of “not at treatment goal” in your impression and “prescription drug management” in your plan tells an auditor what you are thinking and doing.^1,5

The Takeaway—Clearly if a GEP is performed, there is a single CPT code used—99204 or 99214. If the biopsy is performed, there would be a biopsy code and an E/M code with a modifier −25 attached to the latter. For the documentation below, a 99204 or 99214 would be the chosen E/M code:

• CC: (1) New spot on left cheek that seems to be growing and changing shape rapidly; (2) Silvery spots on elbows, knees, and buttocks for which patient desires treatment.
• History: No family history of skin cancer; concerned about scarring, no blood thinner. Mom has psoriasis. Tried petroleum jelly on scaly areas but no better.
• Examination: Irregular tan to brown to black 8-mm macule. No lymphadenopathy. Silver scaly erythematous plaques on elbows, knees, sacrum.
• Impression: (1) Rule out melanoma (undiagnosed new problem with uncertain prognosis); (2) Psoriasis (chronic disease not at treatment goal).
• Plan: (1) Discuss risks, benefits, and alternatives, including biopsy (decision regarding minor surgery with identified patient or procedure risk factors) vs a noninvasive GEP melanoma rule-out test. Patient wants biopsy. Consent, biopsy via shave technique. Lidocaine hydrochloride 1% with epinephrine 1 cc, prepare and drape, aluminum chloride for hemostasis, ointment and bandage applied, care instructions provided; (2) Discuss options. Calcipotriene cream daily; triamcinolone ointment 0.1% twice a day (prescription drug management). Review bathing, avoiding trauma to site, no picking.

Scenario 4: Here for a Total-Body Screening Examination

Medicare does not cover skin cancer screenings as a primary CC. Being worried or knowing someone with melanoma are not CCs that are covered. However, “spot of concern,” “changing mole,” or ”new growth” would be. Conversely, if the patient has a history of skin cancer, actinic keratoses, or other premalignant lesions, and/or is immunosuppressed or has a high-risk genetic syndrome, the visit may be covered if these factors are documented in the note.⁶

For the diagnosis, the International Classification of Diseases, Tenth Revision, code Z12.83—“encounter for screening for malignant neoplasm of skin”—is not an appropriate primary billing code. However, D48.5—“neoplasm of behavior of skin”—can be, unless there is a specific diagnosis you are able to make (eg, melanocytic nevus, seborrheic keratosis).⁶

Let’s look at documentation examples:

• CC: 1-year follow-up on basal cell carcinoma (BCC) excision and concern about a new spot on the nose.
• History: Notice new spot on the nose; due for annual follow-up and came early for nose lesion.
• Examination: Left ala with flesh-colored papule dermoscopically banal. Prior left back BCC excision site soft and supple. Total-body examination performed, except perianal and external genitalia, and is unremarkable.
• Impression: Fibrous papule of nose and prior BCC treatment site with no sign of recurrence.
• Plan: Reassure. Annual surveillance in 1 year.

Using what we have previously discussed, this would likely be considered CPT code 99212 (established patient office visit). However, it is important to ensure all concerns and treatment interventions are fully documented. Consider this fuller documentation with bolded additions:

• CC: 1-year follow-up on BCC excision and concern about a new spot on the nose.
• History: Notice new spot on the nose; due for annual follow-up and came early for nose lesion. Also unhappy with generally looking older.
• Examination: Left ala with flesh-colored papule dermoscopically banal. Prior left back BCC excision site soft and supple. Diffuse changes of chronic sun damage. Total-body examination performed, except perianal and external genitalia, and is unremarkable.
• Impression: Fibrous papule of nose and prior BCC treatment site with no sign of recurrence and heliodermatosis/chronic sun damage not at treat-ment goal.
• Plan: Reassure. Annual surveillance in 1 year. Over-the-counter broad-spectrum sun protection factor 30+ sunscreen daily.

This is better but still possibly confusing to an auditor. Consider instead with bolded additions to the changes to the impression:

• CC: 1-year follow-up on BCC excision and concern about a new spot on the nose.
• History: Notice new spot on the nose; due for annual follow-up and came early for nose lesion. Also unhappy with generally looking older.
• Examination: Left ala with flesh-colored papule dermoscopically banal. Prior left back BCC excision site soft and supple. Diffuse changes of chronic sun damage. Total-body examination performed, except perianal and external genitalia, and is unremarkable.
• Impression: Fibrous papule of nose (D22.39)⁷ and prior BCC treatment site with no sign of recurrence (Z85.828: “personal history of other malignant neoplasm of skin) and heliodermatosis/chronic sun damage not at treatment goal (L57.8: “other skin changes due to chronic exposure to nonionizing radiation”).
• Plan: Reassure. Annual surveillance 1 year. Over-the-counter broad-spectrum sun protection factor 30+ sunscreen daily.

We now have chronic heliodermatitis not at treatment goal, which is moderate (column 1, level 4), and the over-the-counter broad-spectrum sun protection factor 30+ sunscreen (column 1, low) would be best coded as CPT code 99213.

Final Thoughts

“Spot check” encounters are common dermatologic visits, both on their own and in combination with other concerns. With the updated E/M guidelines, it is crucial to clarify and streamline your documentation. In particular, utilize language clearly defining the number and complexity of problems, data to be reviewed and/or analyzed, and appropriate risk stratification to ensure appropriate reimbursement and minimize your difficulties with audits.

The Diagnosis: Dominant Dystrophic Epidermolysis Bullosa

Blisters in a neonate may be caused by infectious, traumatic, autoimmune, or congenital etiologies. Biopsy findings correlated with clinical findings usually can establish a prompt diagnosis when the clinical diagnosis is uncertain. Direct immunofluorescence (DIF) as well as indirect immunofluorescence studies are useful when autoimmune blistering disease or congenital or heritable disorders of skin fragility are in the differential diagnosis. Many genetic abnormalities of skin fragility are associated with marked morbidity and mortality, and prompt diagnosis is essential to provide proper care. Our patient’s parents had no history of skin disorders, and there was no known family history of blistering disease or traumatic birth. A heritable disorder of skin fragility was still a top consideration because of the extensive blistering in the absence of any other symptoms.

Although dystrophic epidermolysis bullosa (DEB) is an uncommon cause of skin fragility in neonates, our patient’s presentation was typical because of the extensive blistering and increased fragility of the skin at pressure points. Dystrophic epidermolysis bullosa has both dominant and recessive presentations that span a spectrum from mild and focal skin blistering to extensive blistering with esophageal involvement.¹ Early diagnosis and treatment can mitigate potential failure to thrive or premature death. Inherited mutations in the type VII collagen gene, COL7A1, are causative.² Dominant DEB may be associated with dental caries, swallowing problems secondary to esophageal scarring, and constipation, as well as dystrophic or absent nails. Immunomapping studies of the skin often reveal type VII collagen cytoplasmic granules in the epidermis and weaker reaction in the roof of the subepidermal separation (quiz image).³ Abnormalities in type VII collagen impact the production of anchoring fibrils. Blister cleavage occurs in the sublamina densa with type VII collagen staining evident on the blister roof (quiz image).⁴ Patients with severe generalized recessive DEB may have barely detectable type VII collagen. In our patient, the cytoplasmic staining and weak staining in the epidermal roof of the separation confirmed the clinical impression of dominant DEB.

Autoimmune blistering disease should be considered in the histologic differential diagnosis, but it usually is associated with obvious disease in the mother. Direct immunofluorescence of pemphigoid gestationis reveals linear deposition of C3 at the basement membrane zone, which also can be associated with IgG (Figure 1). Neonates receiving passive transfer of antibodies may develop annular erythema, vesicles, and even dyshidroticlike changes on the soles.⁵

Suction blisters are subepithelial.^6,7 When they occur in the neonatal period, they often are localized and are thought to be the result of vigorous sucking in utero.⁶ They quickly resolve without treatment and do not reveal abnormalities on DIF. If immunomapping is done for type VII collagen, it will be located at the floor of the suction blister (Figure 2).

Bullous pemphigoid is associated with deposition of linear IgG along the dermoepidermal junction—IgG4 is most common—and/or C3 (Figure 3). Direct immunofluorescence on split-skin biopsy reveals IgG on the epidermal side of the blister in bullous pemphigoid in contrast to epidermolysis bullosa acquisita, where the immune deposits are found on the dermal side of the split.^8,9 Linear IgA bullous disease is associated with IgA deposition (Figure 4).^10,11 Secretory IgA derived from breast milk can be causative.¹¹ Neonatal linear IgA bullous disease is a serious condition associated with marked mucosal involvement that can eventuate in respiratory compromise. Prompt recognition is important; breastfeeding must be stopped and supportive therapy must be provided.

Other types of vesicular or pustular eruptions in the newborn usually are easily diagnosed by their typical clinical presentation without biopsy. Erythema toxicum neonatorum usually presents within 1 to 2 days of birth. It is self-limited and often resembles acne, but it also occurs on the trunk and extremities. Transient neonatal pustular melanosis may be present at birth and predominantly is seen in newborns with skin of color. Lesions easily rupture and usually resolve within 1 to 2 days. Infectious causes of blistering often can be identified on clinical examination and confirmed by culture. Herpes simplex virus infection is associated with characteristic multinucleated giant cells as well as steel grey nuclei evident on routine histologic evaluation. Bullous impetigo reveals superficial acantholysis and will have negative findings on DIF.¹²

When a neonate presents with widespread blistering, both genetic disorders of skin fragility as well as passive transfer of antibodies from maternal autoimmune disease need to be considered. Direct immunofluorescence and indirect immunofluorescence immunomapping findings can be useful in clarifying the diagnosis when heritable disorders of skin fragility or autoimmune blistering diseases are a clinical consideration.

The Diagnosis: Dominant Dystrophic Epidermolysis Bullosa

Blisters in a neonate may be caused by infectious, traumatic, autoimmune, or congenital etiologies. Biopsy findings correlated with clinical findings usually can establish a prompt diagnosis when the clinical diagnosis is uncertain. Direct immunofluorescence (DIF) as well as indirect immunofluorescence studies are useful when autoimmune blistering disease or congenital or heritable disorders of skin fragility are in the differential diagnosis. Many genetic abnormalities of skin fragility are associated with marked morbidity and mortality, and prompt diagnosis is essential to provide proper care. Our patient’s parents had no history of skin disorders, and there was no known family history of blistering disease or traumatic birth. A heritable disorder of skin fragility was still a top consideration because of the extensive blistering in the absence of any other symptoms.

Although dystrophic epidermolysis bullosa (DEB) is an uncommon cause of skin fragility in neonates, our patient’s presentation was typical because of the extensive blistering and increased fragility of the skin at pressure points. Dystrophic epidermolysis bullosa has both dominant and recessive presentations that span a spectrum from mild and focal skin blistering to extensive blistering with esophageal involvement.¹ Early diagnosis and treatment can mitigate potential failure to thrive or premature death. Inherited mutations in the type VII collagen gene, COL7A1, are causative.² Dominant DEB may be associated with dental caries, swallowing problems secondary to esophageal scarring, and constipation, as well as dystrophic or absent nails. Immunomapping studies of the skin often reveal type VII collagen cytoplasmic granules in the epidermis and weaker reaction in the roof of the subepidermal separation (quiz image).³ Abnormalities in type VII collagen impact the production of anchoring fibrils. Blister cleavage occurs in the sublamina densa with type VII collagen staining evident on the blister roof (quiz image).⁴ Patients with severe generalized recessive DEB may have barely detectable type VII collagen. In our patient, the cytoplasmic staining and weak staining in the epidermal roof of the separation confirmed the clinical impression of dominant DEB.

Autoimmune blistering disease should be considered in the histologic differential diagnosis, but it usually is associated with obvious disease in the mother. Direct immunofluorescence of pemphigoid gestationis reveals linear deposition of C3 at the basement membrane zone, which also can be associated with IgG (Figure 1). Neonates receiving passive transfer of antibodies may develop annular erythema, vesicles, and even dyshidroticlike changes on the soles.⁵

Suction blisters are subepithelial.^6,7 When they occur in the neonatal period, they often are localized and are thought to be the result of vigorous sucking in utero.⁶ They quickly resolve without treatment and do not reveal abnormalities on DIF. If immunomapping is done for type VII collagen, it will be located at the floor of the suction blister (Figure 2).

Bullous pemphigoid is associated with deposition of linear IgG along the dermoepidermal junction—IgG4 is most common—and/or C3 (Figure 3). Direct immunofluorescence on split-skin biopsy reveals IgG on the epidermal side of the blister in bullous pemphigoid in contrast to epidermolysis bullosa acquisita, where the immune deposits are found on the dermal side of the split.^8,9 Linear IgA bullous disease is associated with IgA deposition (Figure 4).^10,11 Secretory IgA derived from breast milk can be causative.¹¹ Neonatal linear IgA bullous disease is a serious condition associated with marked mucosal involvement that can eventuate in respiratory compromise. Prompt recognition is important; breastfeeding must be stopped and supportive therapy must be provided.

Other types of vesicular or pustular eruptions in the newborn usually are easily diagnosed by their typical clinical presentation without biopsy. Erythema toxicum neonatorum usually presents within 1 to 2 days of birth. It is self-limited and often resembles acne, but it also occurs on the trunk and extremities. Transient neonatal pustular melanosis may be present at birth and predominantly is seen in newborns with skin of color. Lesions easily rupture and usually resolve within 1 to 2 days. Infectious causes of blistering often can be identified on clinical examination and confirmed by culture. Herpes simplex virus infection is associated with characteristic multinucleated giant cells as well as steel grey nuclei evident on routine histologic evaluation. Bullous impetigo reveals superficial acantholysis and will have negative findings on DIF.¹²

When a neonate presents with widespread blistering, both genetic disorders of skin fragility as well as passive transfer of antibodies from maternal autoimmune disease need to be considered. Direct immunofluorescence and indirect immunofluorescence immunomapping findings can be useful in clarifying the diagnosis when heritable disorders of skin fragility or autoimmune blistering diseases are a clinical consideration.

The Diagnosis: Dominant Dystrophic Epidermolysis Bullosa

Blisters in a neonate may be caused by infectious, traumatic, autoimmune, or congenital etiologies. Biopsy findings correlated with clinical findings usually can establish a prompt diagnosis when the clinical diagnosis is uncertain. Direct immunofluorescence (DIF) as well as indirect immunofluorescence studies are useful when autoimmune blistering disease or congenital or heritable disorders of skin fragility are in the differential diagnosis. Many genetic abnormalities of skin fragility are associated with marked morbidity and mortality, and prompt diagnosis is essential to provide proper care. Our patient’s parents had no history of skin disorders, and there was no known family history of blistering disease or traumatic birth. A heritable disorder of skin fragility was still a top consideration because of the extensive blistering in the absence of any other symptoms.

Although dystrophic epidermolysis bullosa (DEB) is an uncommon cause of skin fragility in neonates, our patient’s presentation was typical because of the extensive blistering and increased fragility of the skin at pressure points. Dystrophic epidermolysis bullosa has both dominant and recessive presentations that span a spectrum from mild and focal skin blistering to extensive blistering with esophageal involvement.¹ Early diagnosis and treatment can mitigate potential failure to thrive or premature death. Inherited mutations in the type VII collagen gene, COL7A1, are causative.² Dominant DEB may be associated with dental caries, swallowing problems secondary to esophageal scarring, and constipation, as well as dystrophic or absent nails. Immunomapping studies of the skin often reveal type VII collagen cytoplasmic granules in the epidermis and weaker reaction in the roof of the subepidermal separation (quiz image).³ Abnormalities in type VII collagen impact the production of anchoring fibrils. Blister cleavage occurs in the sublamina densa with type VII collagen staining evident on the blister roof (quiz image).⁴ Patients with severe generalized recessive DEB may have barely detectable type VII collagen. In our patient, the cytoplasmic staining and weak staining in the epidermal roof of the separation confirmed the clinical impression of dominant DEB.

Autoimmune blistering disease should be considered in the histologic differential diagnosis, but it usually is associated with obvious disease in the mother. Direct immunofluorescence of pemphigoid gestationis reveals linear deposition of C3 at the basement membrane zone, which also can be associated with IgG (Figure 1). Neonates receiving passive transfer of antibodies may develop annular erythema, vesicles, and even dyshidroticlike changes on the soles.⁵

Suction blisters are subepithelial.^6,7 When they occur in the neonatal period, they often are localized and are thought to be the result of vigorous sucking in utero.⁶ They quickly resolve without treatment and do not reveal abnormalities on DIF. If immunomapping is done for type VII collagen, it will be located at the floor of the suction blister (Figure 2).

Bullous pemphigoid is associated with deposition of linear IgG along the dermoepidermal junction—IgG4 is most common—and/or C3 (Figure 3). Direct immunofluorescence on split-skin biopsy reveals IgG on the epidermal side of the blister in bullous pemphigoid in contrast to epidermolysis bullosa acquisita, where the immune deposits are found on the dermal side of the split.^8,9 Linear IgA bullous disease is associated with IgA deposition (Figure 4).^10,11 Secretory IgA derived from breast milk can be causative.¹¹ Neonatal linear IgA bullous disease is a serious condition associated with marked mucosal involvement that can eventuate in respiratory compromise. Prompt recognition is important; breastfeeding must be stopped and supportive therapy must be provided.

Other types of vesicular or pustular eruptions in the newborn usually are easily diagnosed by their typical clinical presentation without biopsy. Erythema toxicum neonatorum usually presents within 1 to 2 days of birth. It is self-limited and often resembles acne, but it also occurs on the trunk and extremities. Transient neonatal pustular melanosis may be present at birth and predominantly is seen in newborns with skin of color. Lesions easily rupture and usually resolve within 1 to 2 days. Infectious causes of blistering often can be identified on clinical examination and confirmed by culture. Herpes simplex virus infection is associated with characteristic multinucleated giant cells as well as steel grey nuclei evident on routine histologic evaluation. Bullous impetigo reveals superficial acantholysis and will have negative findings on DIF.¹²

When a neonate presents with widespread blistering, both genetic disorders of skin fragility as well as passive transfer of antibodies from maternal autoimmune disease need to be considered. Direct immunofluorescence and indirect immunofluorescence immunomapping findings can be useful in clarifying the diagnosis when heritable disorders of skin fragility or autoimmune blistering diseases are a clinical consideration.

Medical students often perform away rotations (also called visiting electives) to gain exposure to educational experiences in a particular specialty, learn about a program, and show interest in a certain program. Away rotations also allow applicants to meet and form relationships with mentors and faculty outside of their home institution. For residency programs, away rotations provide an opportunity for a holistic review of applicants by allowing program directors to get to know potential residency applicants and assess their performance in the clinical environment and among the program’s team. In a National Resident Matching Program survey, program directors (n=17) reported that prior knowledge of an applicant is an important factor in selecting applicants to interview (82.4%) and rank (58.8%).¹

In this article, we discuss the importance of away rotations in dermatology and provide an overview of the Organization of Program Director Associations (OPDA) and Association of Professors of Dermatology (APD) guidelines for away rotations.

Importance of the Away Rotation in the Match

According to the Association of American Medical Colleges, 86.7% of dermatology applicants (N=345) completed one or more away rotations (mean, 2.7) in 2020.² Winterton et al³ reported that 47% of dermatology applicants (N=45) matched at a program where they completed an away rotation. Prior to the COVID-19 pandemic, the number of applicants matching to their home program was reported as 26.7% (N=641), which jumped to 40.3% (N=231) in the 2020-2021 cycle.⁴ Given that the majority of dermatology applicants reportedly match either at their home program or at programs where they completed an away rotation, the benefits of away rotations are high, particularly in a competitive specialty such as dermatology and particularly for applicants without a dermatology program at their home institution. However, it must be acknowledged that correlation does not necessarily mean causation, as away rotations have not necessarily been shown to increase applicants’ chances of matching for the most competitive specialties.⁵

OPDA Guidelines for Away Rotations

In 2021, the Coalition of Physician Accountability’s Undergraduate Medical Education-Graduate Medical Education Review Committee recommended creating a workgroup to explore the function and value of away rotations for medical students, programs, and institutions, with a particular focus on issues of equity (eg, accessibility, assessment, opportunity) for underrepresented in medicine students and those with financial disadvantages.⁶ The OPDA workgroup evaluated the advantages and disadvantages of away rotations across specialties. The disadvantages included that away rotations may decrease resources to students at their own institution, particularly if faculty time and energy are funneled/dedicated to away rotators instead of internal rotators, and may impart bias into the recruitment process. Additionally, there is a consideration of equity given the considerable cost and time commitment of travel and housing for students at another institution. In 2022, the estimated cost of an away rotation in dermatology ranged from $1390 to $5500 per rotation.⁷ Visiting scholarships may be available at some institutions but typically are reserved for underrepresented in medicine students.⁸ Virtual rotations offered at some programs offset the cost-prohibitiveness of an in-person away rotation; however, they are not universally offered and may be limited in allowing for meaningful interactions between students and program faculty and residents.

The OPDA away rotation workgroup recommended that (1) each specialty publish guidelines regarding the necessity and number of recommended away rotations; (2) specialties publish explicit language regarding the use of program preference signals to programs where students rotated; (3) programs be transparent about the purpose and value of an away rotation, including explicitly stating whether a formal interview is guaranteed; and (4) the Association of American Medical Colleges create a repository of these specialty-specific recommendations.⁹

APD Guidelines for Away Rotations

In response to the OPDA recommendations, the APD Residency Program Directors Section developed dermatology-specific guidelines for away rotations and established guidelines in other specialties.¹⁰ The APD recommends completing up to 2 away rotations, or 3 for those without a home program, if desired. This number was chosen in acknowledgment of the importance of external program experiences, along with the recognition of the financial and time restrictions associated with away rotations as well as the limited number of spots for rotating students. Away rotations are not mandatory. The APD guidelines explain the purpose and value of an away rotation while also noting that these rotations do not necessarily guarantee a formal interview and recommending that programs be transparent about their policies on interview invitations, which may vary.¹⁰

Final Thoughts

Publishing specialty-specific guidelines on away rotations is one step toward streamlining the process as well as increasing transparency on the importance of these external program experiences in the application process and residency match. Ideally, away rotations provide a valuable educational experience in which students and program directors get to know each other in a mutually beneficial manner; however, away rotations are not required for securing an interview or matching at a program, and there also are recognized disadvantages to away rotations, particularly with regard to equity, that we must continue to weigh as a specialty. The APD will continue its collaborative work to evaluate our application processes to support a sustainable and equitable system.

Medical students often perform away rotations (also called visiting electives) to gain exposure to educational experiences in a particular specialty, learn about a program, and show interest in a certain program. Away rotations also allow applicants to meet and form relationships with mentors and faculty outside of their home institution. For residency programs, away rotations provide an opportunity for a holistic review of applicants by allowing program directors to get to know potential residency applicants and assess their performance in the clinical environment and among the program’s team. In a National Resident Matching Program survey, program directors (n=17) reported that prior knowledge of an applicant is an important factor in selecting applicants to interview (82.4%) and rank (58.8%).¹

In this article, we discuss the importance of away rotations in dermatology and provide an overview of the Organization of Program Director Associations (OPDA) and Association of Professors of Dermatology (APD) guidelines for away rotations.

Importance of the Away Rotation in the Match

According to the Association of American Medical Colleges, 86.7% of dermatology applicants (N=345) completed one or more away rotations (mean, 2.7) in 2020.² Winterton et al³ reported that 47% of dermatology applicants (N=45) matched at a program where they completed an away rotation. Prior to the COVID-19 pandemic, the number of applicants matching to their home program was reported as 26.7% (N=641), which jumped to 40.3% (N=231) in the 2020-2021 cycle.⁴ Given that the majority of dermatology applicants reportedly match either at their home program or at programs where they completed an away rotation, the benefits of away rotations are high, particularly in a competitive specialty such as dermatology and particularly for applicants without a dermatology program at their home institution. However, it must be acknowledged that correlation does not necessarily mean causation, as away rotations have not necessarily been shown to increase applicants’ chances of matching for the most competitive specialties.⁵

OPDA Guidelines for Away Rotations

In 2021, the Coalition of Physician Accountability’s Undergraduate Medical Education-Graduate Medical Education Review Committee recommended creating a workgroup to explore the function and value of away rotations for medical students, programs, and institutions, with a particular focus on issues of equity (eg, accessibility, assessment, opportunity) for underrepresented in medicine students and those with financial disadvantages.⁶ The OPDA workgroup evaluated the advantages and disadvantages of away rotations across specialties. The disadvantages included that away rotations may decrease resources to students at their own institution, particularly if faculty time and energy are funneled/dedicated to away rotators instead of internal rotators, and may impart bias into the recruitment process. Additionally, there is a consideration of equity given the considerable cost and time commitment of travel and housing for students at another institution. In 2022, the estimated cost of an away rotation in dermatology ranged from $1390 to $5500 per rotation.⁷ Visiting scholarships may be available at some institutions but typically are reserved for underrepresented in medicine students.⁸ Virtual rotations offered at some programs offset the cost-prohibitiveness of an in-person away rotation; however, they are not universally offered and may be limited in allowing for meaningful interactions between students and program faculty and residents.

The OPDA away rotation workgroup recommended that (1) each specialty publish guidelines regarding the necessity and number of recommended away rotations; (2) specialties publish explicit language regarding the use of program preference signals to programs where students rotated; (3) programs be transparent about the purpose and value of an away rotation, including explicitly stating whether a formal interview is guaranteed; and (4) the Association of American Medical Colleges create a repository of these specialty-specific recommendations.⁹

APD Guidelines for Away Rotations

In response to the OPDA recommendations, the APD Residency Program Directors Section developed dermatology-specific guidelines for away rotations and established guidelines in other specialties.¹⁰ The APD recommends completing up to 2 away rotations, or 3 for those without a home program, if desired. This number was chosen in acknowledgment of the importance of external program experiences, along with the recognition of the financial and time restrictions associated with away rotations as well as the limited number of spots for rotating students. Away rotations are not mandatory. The APD guidelines explain the purpose and value of an away rotation while also noting that these rotations do not necessarily guarantee a formal interview and recommending that programs be transparent about their policies on interview invitations, which may vary.¹⁰

Final Thoughts

Publishing specialty-specific guidelines on away rotations is one step toward streamlining the process as well as increasing transparency on the importance of these external program experiences in the application process and residency match. Ideally, away rotations provide a valuable educational experience in which students and program directors get to know each other in a mutually beneficial manner; however, away rotations are not required for securing an interview or matching at a program, and there also are recognized disadvantages to away rotations, particularly with regard to equity, that we must continue to weigh as a specialty. The APD will continue its collaborative work to evaluate our application processes to support a sustainable and equitable system.

Medical students often perform away rotations (also called visiting electives) to gain exposure to educational experiences in a particular specialty, learn about a program, and show interest in a certain program. Away rotations also allow applicants to meet and form relationships with mentors and faculty outside of their home institution. For residency programs, away rotations provide an opportunity for a holistic review of applicants by allowing program directors to get to know potential residency applicants and assess their performance in the clinical environment and among the program’s team. In a National Resident Matching Program survey, program directors (n=17) reported that prior knowledge of an applicant is an important factor in selecting applicants to interview (82.4%) and rank (58.8%).¹

In this article, we discuss the importance of away rotations in dermatology and provide an overview of the Organization of Program Director Associations (OPDA) and Association of Professors of Dermatology (APD) guidelines for away rotations.

Importance of the Away Rotation in the Match

According to the Association of American Medical Colleges, 86.7% of dermatology applicants (N=345) completed one or more away rotations (mean, 2.7) in 2020.² Winterton et al³ reported that 47% of dermatology applicants (N=45) matched at a program where they completed an away rotation. Prior to the COVID-19 pandemic, the number of applicants matching to their home program was reported as 26.7% (N=641), which jumped to 40.3% (N=231) in the 2020-2021 cycle.⁴ Given that the majority of dermatology applicants reportedly match either at their home program or at programs where they completed an away rotation, the benefits of away rotations are high, particularly in a competitive specialty such as dermatology and particularly for applicants without a dermatology program at their home institution. However, it must be acknowledged that correlation does not necessarily mean causation, as away rotations have not necessarily been shown to increase applicants’ chances of matching for the most competitive specialties.⁵

OPDA Guidelines for Away Rotations

In 2021, the Coalition of Physician Accountability’s Undergraduate Medical Education-Graduate Medical Education Review Committee recommended creating a workgroup to explore the function and value of away rotations for medical students, programs, and institutions, with a particular focus on issues of equity (eg, accessibility, assessment, opportunity) for underrepresented in medicine students and those with financial disadvantages.⁶ The OPDA workgroup evaluated the advantages and disadvantages of away rotations across specialties. The disadvantages included that away rotations may decrease resources to students at their own institution, particularly if faculty time and energy are funneled/dedicated to away rotators instead of internal rotators, and may impart bias into the recruitment process. Additionally, there is a consideration of equity given the considerable cost and time commitment of travel and housing for students at another institution. In 2022, the estimated cost of an away rotation in dermatology ranged from $1390 to $5500 per rotation.⁷ Visiting scholarships may be available at some institutions but typically are reserved for underrepresented in medicine students.⁸ Virtual rotations offered at some programs offset the cost-prohibitiveness of an in-person away rotation; however, they are not universally offered and may be limited in allowing for meaningful interactions between students and program faculty and residents.

The OPDA away rotation workgroup recommended that (1) each specialty publish guidelines regarding the necessity and number of recommended away rotations; (2) specialties publish explicit language regarding the use of program preference signals to programs where students rotated; (3) programs be transparent about the purpose and value of an away rotation, including explicitly stating whether a formal interview is guaranteed; and (4) the Association of American Medical Colleges create a repository of these specialty-specific recommendations.⁹

APD Guidelines for Away Rotations

In response to the OPDA recommendations, the APD Residency Program Directors Section developed dermatology-specific guidelines for away rotations and established guidelines in other specialties.¹⁰ The APD recommends completing up to 2 away rotations, or 3 for those without a home program, if desired. This number was chosen in acknowledgment of the importance of external program experiences, along with the recognition of the financial and time restrictions associated with away rotations as well as the limited number of spots for rotating students. Away rotations are not mandatory. The APD guidelines explain the purpose and value of an away rotation while also noting that these rotations do not necessarily guarantee a formal interview and recommending that programs be transparent about their policies on interview invitations, which may vary.¹⁰

Final Thoughts

Publishing specialty-specific guidelines on away rotations is one step toward streamlining the process as well as increasing transparency on the importance of these external program experiences in the application process and residency match. Ideally, away rotations provide a valuable educational experience in which students and program directors get to know each other in a mutually beneficial manner; however, away rotations are not required for securing an interview or matching at a program, and there also are recognized disadvantages to away rotations, particularly with regard to equity, that we must continue to weigh as a specialty. The APD will continue its collaborative work to evaluate our application processes to support a sustainable and equitable system.

Nearly all dermatologists are aware that psoriatic arthritis (PsA) is one of the most prevalent comorbidities associated with psoriasis, yet we may lack the insight regarding how to utilize this information. After all, we specialize in the skin, not the joints, right?

When I graduated from residency in 2014, I began staffing our psoriasis clinic, where we care for the toughest, most complicated psoriasis patients, many of them struggling with both severe recalcitrant psoriasis as well as debilitating PsA. In 2016, we partnered with rheumatology to open a multidisciplinary psoriasis and PsA clinic, and I quickly began to appreciate how much PsA was being overlooked simply because patients with psoriasis were not being asked about their joints.

To start, let’s look at several facts:

1. One quarter of patients with psoriasis also have PsA.¹
2. Skin disease most commonly develops before PsA.¹
3. Fifteen percent of PsA cases go undiagnosed, which dramatically increases the risk for deformed joints, erosions, osteolysis, sacroiliitis, and arthritis mutilans² and also increases the cost of health care.³
4. Everyone is crazy busy—rheumatology wait lists often are months long.

Given that dermatologists are the ones who already are seeing the majority of patients who develop PsA, we play a key role in screening for this debilitating comorbidity and starting therapy for patients with both psoriasis and PsA. We, too, are crazy busy; therefore, we need to make this process quick and efficient but also reliable. Fortunately, the Psoriasis Epidemiology Screening Tool (PEST) is effective, fast, and very easy. With only 5 questions and a sensitivity and specificity of around 70%,⁴ this short and simple questionnaire can be incorporated into an intake form or rooming note or can just be asked during the visit. The questions include whether the patient currently has or has had a swollen joint, nail pits, heel pain, and/or dactylitis, as well as if they have been told by a physician that they have arthritis. A score of 3 or higher is considered positive and a referral to rheumatology should be considered. At the bare minimum, I highly encourage all dermatologists to incorporate the PEST screening tool into their practice.

During the physical examination itself, be sure to look at the patient’s nails and also look for joint swelling and redness, especially in the hands. When palpating a swollen joint, the presence of inflammatory arthritis will feel spongy or boggy, while the osteophytes associated with osteoarthritis will feel hard. Radiography of the affected joint may be helpful, but keep in mind that bone changes are latter sequelae of PsA, and negative radiographs do not rule out PsA.

If you highly suspect PsA after using the PEST screening tool and palpating any swollen joints, then a rheumatology referral certainly is warranted. Medication that covers both psoriasis and PsA also can be initiated. Although methotrexate often is used for joints, higher doses (ie, >15 mg/wk) usually are needed. A 2019 Cochrane review found that low-dose methotrexate (ie, ≤15 mg/wk) may be only slightly more effective then placebo⁵—certainly not a ringing endorsement for its use in PsA. Additionally, quality data demonstrating methotrexate’s efficacy for enthesitis or axial spondyloarthritis is lacking, and methotrexate has not demonstrated an ability to slow the radiographic progression of joints. In contrast, the anti–tumor necrosis factor agents, including adalimumab, infliximab, etanercept, and certolizumab, as well as ustekinumab and the anti–IL-17 biologics secukinumab and ixekizumab have demonstrated efficacy in American College of Rheumatology (ACR) scores, enthesitis, dactylitis, and prevention of radiographic progression of joints.^6,7 Although brodalumab, an anti–IL-17 receptor inhibitor, demonstrated improvement in ACR scores, enthesitis, and dactylitis, data on its effects on radiographic progression of joints were inconclusive given the phase III trial’s premature ending due to suicidal ideation and behavior in participants.⁸ Several of the anti–IL-23 agents also may help PsA, with trials demonstrating improvements in ACR scores, enthesitis, and dactylitis; however, only guselkumab 100 mg every 4 weeks decreased radiographic progression of joints.⁹ Additionally, with the age of the Janus kinase (JAK) inhibitor upon us, there are several JAK/TYK2 inhibitors that are approved by the US Food and Drug Administration for psoriasis (deucravacitinib) as well as for PsA (tofacitinib, upadacitinib), and there are more JAK inhibitors in the pipeline. These medications are effective; however, I do encourage caution and careful consideration in selecting the appropriate patient, as data demonstrated an increased risk for major adverse cardiovascular events and cancer in older (>50 years) rheumatoid arthritis patients who had at least 1 cardiovascular risk factor and were treated with tofacitinib.¹⁰ Although several other trials have not demonstrated this increased risk, further data are needed to determine risk for both pan-JAK inhibitors as well as selective JAK inhibitors and TYK2 inhibitors. Additionally, given psoriasis already is closely linked with many cardiovascular risk factors including heart disease, obesity, hypertension, hyperlipidemia, and diabetes mellitus,¹¹ it will be important to have long-term safety information for JAK inhibitors in the psoriasis and PsA population.

Dermatologists are in a pivotal position to identify patients affected by PsA and start an appropriate systemic medication. We can help make an enormous impact on our patients’ lives as well as help decrease the economic impact of untreated disease. Let’s join the effort to save the joints!

Nearly all dermatologists are aware that psoriatic arthritis (PsA) is one of the most prevalent comorbidities associated with psoriasis, yet we may lack the insight regarding how to utilize this information. After all, we specialize in the skin, not the joints, right?

When I graduated from residency in 2014, I began staffing our psoriasis clinic, where we care for the toughest, most complicated psoriasis patients, many of them struggling with both severe recalcitrant psoriasis as well as debilitating PsA. In 2016, we partnered with rheumatology to open a multidisciplinary psoriasis and PsA clinic, and I quickly began to appreciate how much PsA was being overlooked simply because patients with psoriasis were not being asked about their joints.

To start, let’s look at several facts:

1. One quarter of patients with psoriasis also have PsA.¹
2. Skin disease most commonly develops before PsA.¹
3. Fifteen percent of PsA cases go undiagnosed, which dramatically increases the risk for deformed joints, erosions, osteolysis, sacroiliitis, and arthritis mutilans² and also increases the cost of health care.³
4. Everyone is crazy busy—rheumatology wait lists often are months long.

Given that dermatologists are the ones who already are seeing the majority of patients who develop PsA, we play a key role in screening for this debilitating comorbidity and starting therapy for patients with both psoriasis and PsA. We, too, are crazy busy; therefore, we need to make this process quick and efficient but also reliable. Fortunately, the Psoriasis Epidemiology Screening Tool (PEST) is effective, fast, and very easy. With only 5 questions and a sensitivity and specificity of around 70%,⁴ this short and simple questionnaire can be incorporated into an intake form or rooming note or can just be asked during the visit. The questions include whether the patient currently has or has had a swollen joint, nail pits, heel pain, and/or dactylitis, as well as if they have been told by a physician that they have arthritis. A score of 3 or higher is considered positive and a referral to rheumatology should be considered. At the bare minimum, I highly encourage all dermatologists to incorporate the PEST screening tool into their practice.

During the physical examination itself, be sure to look at the patient’s nails and also look for joint swelling and redness, especially in the hands. When palpating a swollen joint, the presence of inflammatory arthritis will feel spongy or boggy, while the osteophytes associated with osteoarthritis will feel hard. Radiography of the affected joint may be helpful, but keep in mind that bone changes are latter sequelae of PsA, and negative radiographs do not rule out PsA.

If you highly suspect PsA after using the PEST screening tool and palpating any swollen joints, then a rheumatology referral certainly is warranted. Medication that covers both psoriasis and PsA also can be initiated. Although methotrexate often is used for joints, higher doses (ie, >15 mg/wk) usually are needed. A 2019 Cochrane review found that low-dose methotrexate (ie, ≤15 mg/wk) may be only slightly more effective then placebo⁵—certainly not a ringing endorsement for its use in PsA. Additionally, quality data demonstrating methotrexate’s efficacy for enthesitis or axial spondyloarthritis is lacking, and methotrexate has not demonstrated an ability to slow the radiographic progression of joints. In contrast, the anti–tumor necrosis factor agents, including adalimumab, infliximab, etanercept, and certolizumab, as well as ustekinumab and the anti–IL-17 biologics secukinumab and ixekizumab have demonstrated efficacy in American College of Rheumatology (ACR) scores, enthesitis, dactylitis, and prevention of radiographic progression of joints.^6,7 Although brodalumab, an anti–IL-17 receptor inhibitor, demonstrated improvement in ACR scores, enthesitis, and dactylitis, data on its effects on radiographic progression of joints were inconclusive given the phase III trial’s premature ending due to suicidal ideation and behavior in participants.⁸ Several of the anti–IL-23 agents also may help PsA, with trials demonstrating improvements in ACR scores, enthesitis, and dactylitis; however, only guselkumab 100 mg every 4 weeks decreased radiographic progression of joints.⁹ Additionally, with the age of the Janus kinase (JAK) inhibitor upon us, there are several JAK/TYK2 inhibitors that are approved by the US Food and Drug Administration for psoriasis (deucravacitinib) as well as for PsA (tofacitinib, upadacitinib), and there are more JAK inhibitors in the pipeline. These medications are effective; however, I do encourage caution and careful consideration in selecting the appropriate patient, as data demonstrated an increased risk for major adverse cardiovascular events and cancer in older (>50 years) rheumatoid arthritis patients who had at least 1 cardiovascular risk factor and were treated with tofacitinib.¹⁰ Although several other trials have not demonstrated this increased risk, further data are needed to determine risk for both pan-JAK inhibitors as well as selective JAK inhibitors and TYK2 inhibitors. Additionally, given psoriasis already is closely linked with many cardiovascular risk factors including heart disease, obesity, hypertension, hyperlipidemia, and diabetes mellitus,¹¹ it will be important to have long-term safety information for JAK inhibitors in the psoriasis and PsA population.

Dermatologists are in a pivotal position to identify patients affected by PsA and start an appropriate systemic medication. We can help make an enormous impact on our patients’ lives as well as help decrease the economic impact of untreated disease. Let’s join the effort to save the joints!

Nearly all dermatologists are aware that psoriatic arthritis (PsA) is one of the most prevalent comorbidities associated with psoriasis, yet we may lack the insight regarding how to utilize this information. After all, we specialize in the skin, not the joints, right?

When I graduated from residency in 2014, I began staffing our psoriasis clinic, where we care for the toughest, most complicated psoriasis patients, many of them struggling with both severe recalcitrant psoriasis as well as debilitating PsA. In 2016, we partnered with rheumatology to open a multidisciplinary psoriasis and PsA clinic, and I quickly began to appreciate how much PsA was being overlooked simply because patients with psoriasis were not being asked about their joints.

To start, let’s look at several facts:

1. One quarter of patients with psoriasis also have PsA.¹
2. Skin disease most commonly develops before PsA.¹
3. Fifteen percent of PsA cases go undiagnosed, which dramatically increases the risk for deformed joints, erosions, osteolysis, sacroiliitis, and arthritis mutilans² and also increases the cost of health care.³
4. Everyone is crazy busy—rheumatology wait lists often are months long.

Given that dermatologists are the ones who already are seeing the majority of patients who develop PsA, we play a key role in screening for this debilitating comorbidity and starting therapy for patients with both psoriasis and PsA. We, too, are crazy busy; therefore, we need to make this process quick and efficient but also reliable. Fortunately, the Psoriasis Epidemiology Screening Tool (PEST) is effective, fast, and very easy. With only 5 questions and a sensitivity and specificity of around 70%,⁴ this short and simple questionnaire can be incorporated into an intake form or rooming note or can just be asked during the visit. The questions include whether the patient currently has or has had a swollen joint, nail pits, heel pain, and/or dactylitis, as well as if they have been told by a physician that they have arthritis. A score of 3 or higher is considered positive and a referral to rheumatology should be considered. At the bare minimum, I highly encourage all dermatologists to incorporate the PEST screening tool into their practice.

During the physical examination itself, be sure to look at the patient’s nails and also look for joint swelling and redness, especially in the hands. When palpating a swollen joint, the presence of inflammatory arthritis will feel spongy or boggy, while the osteophytes associated with osteoarthritis will feel hard. Radiography of the affected joint may be helpful, but keep in mind that bone changes are latter sequelae of PsA, and negative radiographs do not rule out PsA.

If you highly suspect PsA after using the PEST screening tool and palpating any swollen joints, then a rheumatology referral certainly is warranted. Medication that covers both psoriasis and PsA also can be initiated. Although methotrexate often is used for joints, higher doses (ie, >15 mg/wk) usually are needed. A 2019 Cochrane review found that low-dose methotrexate (ie, ≤15 mg/wk) may be only slightly more effective then placebo⁵—certainly not a ringing endorsement for its use in PsA. Additionally, quality data demonstrating methotrexate’s efficacy for enthesitis or axial spondyloarthritis is lacking, and methotrexate has not demonstrated an ability to slow the radiographic progression of joints. In contrast, the anti–tumor necrosis factor agents, including adalimumab, infliximab, etanercept, and certolizumab, as well as ustekinumab and the anti–IL-17 biologics secukinumab and ixekizumab have demonstrated efficacy in American College of Rheumatology (ACR) scores, enthesitis, dactylitis, and prevention of radiographic progression of joints.^6,7 Although brodalumab, an anti–IL-17 receptor inhibitor, demonstrated improvement in ACR scores, enthesitis, and dactylitis, data on its effects on radiographic progression of joints were inconclusive given the phase III trial’s premature ending due to suicidal ideation and behavior in participants.⁸ Several of the anti–IL-23 agents also may help PsA, with trials demonstrating improvements in ACR scores, enthesitis, and dactylitis; however, only guselkumab 100 mg every 4 weeks decreased radiographic progression of joints.⁹ Additionally, with the age of the Janus kinase (JAK) inhibitor upon us, there are several JAK/TYK2 inhibitors that are approved by the US Food and Drug Administration for psoriasis (deucravacitinib) as well as for PsA (tofacitinib, upadacitinib), and there are more JAK inhibitors in the pipeline. These medications are effective; however, I do encourage caution and careful consideration in selecting the appropriate patient, as data demonstrated an increased risk for major adverse cardiovascular events and cancer in older (>50 years) rheumatoid arthritis patients who had at least 1 cardiovascular risk factor and were treated with tofacitinib.¹⁰ Although several other trials have not demonstrated this increased risk, further data are needed to determine risk for both pan-JAK inhibitors as well as selective JAK inhibitors and TYK2 inhibitors. Additionally, given psoriasis already is closely linked with many cardiovascular risk factors including heart disease, obesity, hypertension, hyperlipidemia, and diabetes mellitus,¹¹ it will be important to have long-term safety information for JAK inhibitors in the psoriasis and PsA population.

Dermatologists are in a pivotal position to identify patients affected by PsA and start an appropriate systemic medication. We can help make an enormous impact on our patients’ lives as well as help decrease the economic impact of untreated disease. Let’s join the effort to save the joints!