Cutis

To the Editor:

Chronic cutaneous lupus erythematosus (CCLE) is an inflammatory condition with myriad cutaneous manifestations. Most forms of CCLE have the potential to progress to systemic lupus erythematosus (SLE).¹

Blaschkolinear lupus erythematosus (BLE) is an exceedingly rare subtype of cutaneous lupus erythematosus that usually manifests during childhood as linear plaques along the lines of Blaschko.^2,3 Under normal conditions, Blaschko lines are not noticeable; they correspond to the direction of ectodermal cell migration during cutaneous embryogenesis.^4,5 The embryonic cells travel ventrolaterally, forming a V-shaped pattern on the back, an S-shaped pattern on the trunk, and an hourglass-shaped pattern on the face with several perpendicular intersections near the mouth and nose.⁶ During their migration, the cells are susceptible to somatic mutations and clonal expansion, resulting in a monoclonal population of genetically heterogenous cells. This phenomenon is known as somatic mosaicism and may lead to an increased susceptibility to an array of congenital and inflammatory dermatoses, such as cutaneous lupus erythematosus.⁴ Blaschkolinear entities tend to manifest in a unilateral distribution following exposure to a certain environmental trigger, such as trauma, viral illness, or UV radiation, although a trigger is not always present.⁷ We report a case of BLE manifesting on the head and neck in an adult patient.

A 46-year-old man presented with a pruritic rash of 3 months’ duration on the right cheek that extended inferiorly to the right upper chest. He had a medical history of well-controlled psoriasis, and he denied any antecedent trauma, fevers, chills, arthralgia, or night sweats. There had been no improvement with mometasone ointment 0.1% applied daily for 2 months as prescribed by his primary care provider. Physical examination revealed indurated, red-brown, atrophic plaques in a blaschkolinear distribution around the nose, right upper jaw, right side of the neck, and right upper chest (Figure, A).

To the Editor:

Chronic cutaneous lupus erythematosus (CCLE) is an inflammatory condition with myriad cutaneous manifestations. Most forms of CCLE have the potential to progress to systemic lupus erythematosus (SLE).¹

Blaschkolinear lupus erythematosus (BLE) is an exceedingly rare subtype of cutaneous lupus erythematosus that usually manifests during childhood as linear plaques along the lines of Blaschko.^2,3 Under normal conditions, Blaschko lines are not noticeable; they correspond to the direction of ectodermal cell migration during cutaneous embryogenesis.^4,5 The embryonic cells travel ventrolaterally, forming a V-shaped pattern on the back, an S-shaped pattern on the trunk, and an hourglass-shaped pattern on the face with several perpendicular intersections near the mouth and nose.⁶ During their migration, the cells are susceptible to somatic mutations and clonal expansion, resulting in a monoclonal population of genetically heterogenous cells. This phenomenon is known as somatic mosaicism and may lead to an increased susceptibility to an array of congenital and inflammatory dermatoses, such as cutaneous lupus erythematosus.⁴ Blaschkolinear entities tend to manifest in a unilateral distribution following exposure to a certain environmental trigger, such as trauma, viral illness, or UV radiation, although a trigger is not always present.⁷ We report a case of BLE manifesting on the head and neck in an adult patient.

A 46-year-old man presented with a pruritic rash of 3 months’ duration on the right cheek that extended inferiorly to the right upper chest. He had a medical history of well-controlled psoriasis, and he denied any antecedent trauma, fevers, chills, arthralgia, or night sweats. There had been no improvement with mometasone ointment 0.1% applied daily for 2 months as prescribed by his primary care provider. Physical examination revealed indurated, red-brown, atrophic plaques in a blaschkolinear distribution around the nose, right upper jaw, right side of the neck, and right upper chest (Figure, A).

To the Editor:

Chronic cutaneous lupus erythematosus (CCLE) is an inflammatory condition with myriad cutaneous manifestations. Most forms of CCLE have the potential to progress to systemic lupus erythematosus (SLE).¹

Blaschkolinear lupus erythematosus (BLE) is an exceedingly rare subtype of cutaneous lupus erythematosus that usually manifests during childhood as linear plaques along the lines of Blaschko.^2,3 Under normal conditions, Blaschko lines are not noticeable; they correspond to the direction of ectodermal cell migration during cutaneous embryogenesis.^4,5 The embryonic cells travel ventrolaterally, forming a V-shaped pattern on the back, an S-shaped pattern on the trunk, and an hourglass-shaped pattern on the face with several perpendicular intersections near the mouth and nose.⁶ During their migration, the cells are susceptible to somatic mutations and clonal expansion, resulting in a monoclonal population of genetically heterogenous cells. This phenomenon is known as somatic mosaicism and may lead to an increased susceptibility to an array of congenital and inflammatory dermatoses, such as cutaneous lupus erythematosus.⁴ Blaschkolinear entities tend to manifest in a unilateral distribution following exposure to a certain environmental trigger, such as trauma, viral illness, or UV radiation, although a trigger is not always present.⁷ We report a case of BLE manifesting on the head and neck in an adult patient.

A 46-year-old man presented with a pruritic rash of 3 months’ duration on the right cheek that extended inferiorly to the right upper chest. He had a medical history of well-controlled psoriasis, and he denied any antecedent trauma, fevers, chills, arthralgia, or night sweats. There had been no improvement with mometasone ointment 0.1% applied daily for 2 months as prescribed by his primary care provider. Physical examination revealed indurated, red-brown, atrophic plaques in a blaschkolinear distribution around the nose, right upper jaw, right side of the neck, and right upper chest (Figure, A).

The Diagnosis: Pityriasis Lichenoides et Varioliformis Acuta

Sectioned punch biopsies were performed on the patient’s right arm. Histopathology showed acanthosis and parakeratosis in the epidermis, with vacuolar degeneration and dyskeratosis in the basal layer. Dermal changes included extravasated red blood cells in the papillary dermis as well as perivascular lymphocytic infiltrates in both the papillary and reticular dermis (Figure). Direct immunofluorescence of a perilesional biopsy using anti–human IgG, IgM, IgA, C3, and fibrin conjugates showed no findings of immune deposition. Biopsy results were consistent with pityriasis lichenoides et varioliformis acuta (PLEVA), and the patient was treated with a 5-day course of oral azithromycin, triamcinolone ointment 0.1% twice daily, and phototherapy with narrowband UVB ³ times weekly. Rapid improvement was noted at 2-month follow-up.

Pityriasis lichenoides et varioliformis acuta is a form of pityriasis lichenoides, a group of inflammatory dermatoses that are characterized clinically by successive crops of morphologically diverse lesions. Epidemiologic studies have shown a slight male predominance. It primarily affects children and young adults, with peak ages of 8 and 32 years in pediatric and adult populations, respectively.¹

The pathogenesis of PLEVA remains unclear. An abnormal immune response to Toxoplasma, Epstein-Barr virus, HIV, and other pathogens has been suggested based on serologic evidence of concurrent disease activity with the onset of lesions as well as cutaneous improvement in some patients after treatment of the infection.¹ A T-cell lymphoproliferative etiology also has been considered based on histopathologic similarities between PLEVA and lymphomatoid papulosis (LyP) as well as findings of clonality in T-cell receptor gene rearrangement in many patients.^1,2 Some clinicians consider LyP and PLEVA as separate entities on one disease spectrum.

Eruptions of PLEVA tend to favor the trunk and proximal extremities. Lesions may begin as macules measuring 2 to 3 mm in diameter that quickly evolve into papules with fine scale that remains attached centrally. Ulcerations with hemorrhagic crusts also may be noted as the lesions progress in stage. The rash may persist for weeks to years, and overlapping crops of macules and papules at varying stages of development may be seen in the same patient.¹

Histopathologic findings of PLEVA include spongiosis, dyskeratosis, parakeratosis, and focal keratinocyte necrosis within the epidermis, as well as vacuolar degeneration of the basal layer. Lymphocyte and erythrocyte extravasation may extend into the epidermis. Dermal findings may include edema and wedge-shaped perivascular lymphocytic infiltrates extending into the reticular dermis.¹

Important differential diagnoses to consider include LyP, mycosis fungoides (MF), pemphigus foliaceus, and varicella. Lymphomatoid papulosis is a benign CD30+ lymphoproliferative disorder that is characterized by an indolent course of recurrent, often self-resolving papules that occur most frequently on the trunk, arms, and legs of older patients. There are several histologic subtypes of LyP, but the most common (type A) may manifest with wedge-shaped perivascular lymphocytic infiltrates in the dermis, similar to PLEVA. T-cell receptor gene rearrangement studies characteristically reveal clonality in LyP, and clonality has been reported in PLEVA. However, LyP demonstrates a higher cytologic grade and lacks the characteristic parakeratotic scale and superficial dermal microhemorrhage of PLEVA.³

Mycosis fungoides is a malignant lymphoproliferative disorder that is characterized by an indolent clinical course of persistent patches, plaques, or tumors of various sizes that often manifest in non–sun-exposed areas of the skin. Early stages of MF are difficult to detect histologically, but biopsies may show atypical lymphocytes with hyperchromatic, irregularly contoured nuclei arranged along the basal layer of the epidermis. Epidermal aggregates of atypical lymphocytes (also known as Pautrier microabscesses) are considered highly specific for MF. T-cell receptor and immunopathologic studies also are important adjuncts in the diagnosis of MF.⁴

Pemphigus foliaceus is an autoimmune blistering disease caused by antibodies directed against desmoglein 1, which is found in the granular layer of the epidermis. It manifests with a subtle onset of scattered crusted lesions in the seborrheic areas, such as the scalp, face, chest, and upper back. Histopathologic findings of early blisters may include acantholysis and dyskeratosis in the stratum granulosum as well as vacuolization of the granular layer. The blisters may coalesce into superficial bullae containing fibrin and neutrophils. Immunofluorescence studies that demonstrate intraepidermal C3 and IgG deposition are key to the diagnosis of pemphigus.⁵

Varicella (also known as chickenpox) manifests with crops of vesicles on an erythematous base in a centripetal distribution favoring the trunk and proximal extremities. It often is preceded by prodromal fever, malaise, and myalgia. Histopathologic evaluation of varicella is uncommon but may reveal acantholysis, multinucleation, and nuclear margination of keratinocytes. Viral culture or nucleic acid amplification testing of lesions can be used to verify the diagnosis.⁶

Most cases of PLEVA resolve without intervention.7 Treatment is directed at speeding recovery, providing symptomatic relief, and limiting permanent sequelae. Topical steroids often are used to alleviate inflammation and pruritus. Systemic antibiotics such as doxycycline, minocycline, and erythromycin have been used for their anti-inflammatory properties. Phototherapy of various wavelengths, including broadband and narrowband UVB as well as psoralen plus UVA, have led to improvements in affected patients. Refractory disease may warrant consideration of therapy with methotrexate, acitretin, dapsone, or cyclosporine.⁷

There have been rare reports of PLEVA evolving into its potentially lethal variant, febrile ulceronecrotic Mucha-Habermann disease, which is differentiated by the presence of systemic manifestations, including high fever, sore throat, diarrhea, central nervous system symptoms, abdominal pain, interstitial pneumonitis, splenomegaly, arthritis, sepsis, megaloblastic anemia, or conjunctival ulcers. The orogenital mucosa may be affected. Cutaneous lesions may rapidly progress to large, generalized, coalescent ulcers with necrotic crusts and vasculitic features on biopsy.8 Malignant transformation of PLEVA into LyP or MF rarely may occur and warrants continued follow-up of unresolved lesions.⁹

The Diagnosis: Pityriasis Lichenoides et Varioliformis Acuta

Sectioned punch biopsies were performed on the patient’s right arm. Histopathology showed acanthosis and parakeratosis in the epidermis, with vacuolar degeneration and dyskeratosis in the basal layer. Dermal changes included extravasated red blood cells in the papillary dermis as well as perivascular lymphocytic infiltrates in both the papillary and reticular dermis (Figure). Direct immunofluorescence of a perilesional biopsy using anti–human IgG, IgM, IgA, C3, and fibrin conjugates showed no findings of immune deposition. Biopsy results were consistent with pityriasis lichenoides et varioliformis acuta (PLEVA), and the patient was treated with a 5-day course of oral azithromycin, triamcinolone ointment 0.1% twice daily, and phototherapy with narrowband UVB ³ times weekly. Rapid improvement was noted at 2-month follow-up.

Pityriasis lichenoides et varioliformis acuta is a form of pityriasis lichenoides, a group of inflammatory dermatoses that are characterized clinically by successive crops of morphologically diverse lesions. Epidemiologic studies have shown a slight male predominance. It primarily affects children and young adults, with peak ages of 8 and 32 years in pediatric and adult populations, respectively.¹

The pathogenesis of PLEVA remains unclear. An abnormal immune response to Toxoplasma, Epstein-Barr virus, HIV, and other pathogens has been suggested based on serologic evidence of concurrent disease activity with the onset of lesions as well as cutaneous improvement in some patients after treatment of the infection.¹ A T-cell lymphoproliferative etiology also has been considered based on histopathologic similarities between PLEVA and lymphomatoid papulosis (LyP) as well as findings of clonality in T-cell receptor gene rearrangement in many patients.^1,2 Some clinicians consider LyP and PLEVA as separate entities on one disease spectrum.

Eruptions of PLEVA tend to favor the trunk and proximal extremities. Lesions may begin as macules measuring 2 to 3 mm in diameter that quickly evolve into papules with fine scale that remains attached centrally. Ulcerations with hemorrhagic crusts also may be noted as the lesions progress in stage. The rash may persist for weeks to years, and overlapping crops of macules and papules at varying stages of development may be seen in the same patient.¹

Histopathologic findings of PLEVA include spongiosis, dyskeratosis, parakeratosis, and focal keratinocyte necrosis within the epidermis, as well as vacuolar degeneration of the basal layer. Lymphocyte and erythrocyte extravasation may extend into the epidermis. Dermal findings may include edema and wedge-shaped perivascular lymphocytic infiltrates extending into the reticular dermis.¹

Important differential diagnoses to consider include LyP, mycosis fungoides (MF), pemphigus foliaceus, and varicella. Lymphomatoid papulosis is a benign CD30+ lymphoproliferative disorder that is characterized by an indolent course of recurrent, often self-resolving papules that occur most frequently on the trunk, arms, and legs of older patients. There are several histologic subtypes of LyP, but the most common (type A) may manifest with wedge-shaped perivascular lymphocytic infiltrates in the dermis, similar to PLEVA. T-cell receptor gene rearrangement studies characteristically reveal clonality in LyP, and clonality has been reported in PLEVA. However, LyP demonstrates a higher cytologic grade and lacks the characteristic parakeratotic scale and superficial dermal microhemorrhage of PLEVA.³

Mycosis fungoides is a malignant lymphoproliferative disorder that is characterized by an indolent clinical course of persistent patches, plaques, or tumors of various sizes that often manifest in non–sun-exposed areas of the skin. Early stages of MF are difficult to detect histologically, but biopsies may show atypical lymphocytes with hyperchromatic, irregularly contoured nuclei arranged along the basal layer of the epidermis. Epidermal aggregates of atypical lymphocytes (also known as Pautrier microabscesses) are considered highly specific for MF. T-cell receptor and immunopathologic studies also are important adjuncts in the diagnosis of MF.⁴

Pemphigus foliaceus is an autoimmune blistering disease caused by antibodies directed against desmoglein 1, which is found in the granular layer of the epidermis. It manifests with a subtle onset of scattered crusted lesions in the seborrheic areas, such as the scalp, face, chest, and upper back. Histopathologic findings of early blisters may include acantholysis and dyskeratosis in the stratum granulosum as well as vacuolization of the granular layer. The blisters may coalesce into superficial bullae containing fibrin and neutrophils. Immunofluorescence studies that demonstrate intraepidermal C3 and IgG deposition are key to the diagnosis of pemphigus.⁵

Varicella (also known as chickenpox) manifests with crops of vesicles on an erythematous base in a centripetal distribution favoring the trunk and proximal extremities. It often is preceded by prodromal fever, malaise, and myalgia. Histopathologic evaluation of varicella is uncommon but may reveal acantholysis, multinucleation, and nuclear margination of keratinocytes. Viral culture or nucleic acid amplification testing of lesions can be used to verify the diagnosis.⁶

Most cases of PLEVA resolve without intervention.7 Treatment is directed at speeding recovery, providing symptomatic relief, and limiting permanent sequelae. Topical steroids often are used to alleviate inflammation and pruritus. Systemic antibiotics such as doxycycline, minocycline, and erythromycin have been used for their anti-inflammatory properties. Phototherapy of various wavelengths, including broadband and narrowband UVB as well as psoralen plus UVA, have led to improvements in affected patients. Refractory disease may warrant consideration of therapy with methotrexate, acitretin, dapsone, or cyclosporine.⁷

There have been rare reports of PLEVA evolving into its potentially lethal variant, febrile ulceronecrotic Mucha-Habermann disease, which is differentiated by the presence of systemic manifestations, including high fever, sore throat, diarrhea, central nervous system symptoms, abdominal pain, interstitial pneumonitis, splenomegaly, arthritis, sepsis, megaloblastic anemia, or conjunctival ulcers. The orogenital mucosa may be affected. Cutaneous lesions may rapidly progress to large, generalized, coalescent ulcers with necrotic crusts and vasculitic features on biopsy.8 Malignant transformation of PLEVA into LyP or MF rarely may occur and warrants continued follow-up of unresolved lesions.⁹

The Diagnosis: Pityriasis Lichenoides et Varioliformis Acuta

Sectioned punch biopsies were performed on the patient’s right arm. Histopathology showed acanthosis and parakeratosis in the epidermis, with vacuolar degeneration and dyskeratosis in the basal layer. Dermal changes included extravasated red blood cells in the papillary dermis as well as perivascular lymphocytic infiltrates in both the papillary and reticular dermis (Figure). Direct immunofluorescence of a perilesional biopsy using anti–human IgG, IgM, IgA, C3, and fibrin conjugates showed no findings of immune deposition. Biopsy results were consistent with pityriasis lichenoides et varioliformis acuta (PLEVA), and the patient was treated with a 5-day course of oral azithromycin, triamcinolone ointment 0.1% twice daily, and phototherapy with narrowband UVB ³ times weekly. Rapid improvement was noted at 2-month follow-up.

Pityriasis lichenoides et varioliformis acuta is a form of pityriasis lichenoides, a group of inflammatory dermatoses that are characterized clinically by successive crops of morphologically diverse lesions. Epidemiologic studies have shown a slight male predominance. It primarily affects children and young adults, with peak ages of 8 and 32 years in pediatric and adult populations, respectively.¹

The pathogenesis of PLEVA remains unclear. An abnormal immune response to Toxoplasma, Epstein-Barr virus, HIV, and other pathogens has been suggested based on serologic evidence of concurrent disease activity with the onset of lesions as well as cutaneous improvement in some patients after treatment of the infection.¹ A T-cell lymphoproliferative etiology also has been considered based on histopathologic similarities between PLEVA and lymphomatoid papulosis (LyP) as well as findings of clonality in T-cell receptor gene rearrangement in many patients.^1,2 Some clinicians consider LyP and PLEVA as separate entities on one disease spectrum.

Eruptions of PLEVA tend to favor the trunk and proximal extremities. Lesions may begin as macules measuring 2 to 3 mm in diameter that quickly evolve into papules with fine scale that remains attached centrally. Ulcerations with hemorrhagic crusts also may be noted as the lesions progress in stage. The rash may persist for weeks to years, and overlapping crops of macules and papules at varying stages of development may be seen in the same patient.¹

Histopathologic findings of PLEVA include spongiosis, dyskeratosis, parakeratosis, and focal keratinocyte necrosis within the epidermis, as well as vacuolar degeneration of the basal layer. Lymphocyte and erythrocyte extravasation may extend into the epidermis. Dermal findings may include edema and wedge-shaped perivascular lymphocytic infiltrates extending into the reticular dermis.¹

Important differential diagnoses to consider include LyP, mycosis fungoides (MF), pemphigus foliaceus, and varicella. Lymphomatoid papulosis is a benign CD30+ lymphoproliferative disorder that is characterized by an indolent course of recurrent, often self-resolving papules that occur most frequently on the trunk, arms, and legs of older patients. There are several histologic subtypes of LyP, but the most common (type A) may manifest with wedge-shaped perivascular lymphocytic infiltrates in the dermis, similar to PLEVA. T-cell receptor gene rearrangement studies characteristically reveal clonality in LyP, and clonality has been reported in PLEVA. However, LyP demonstrates a higher cytologic grade and lacks the characteristic parakeratotic scale and superficial dermal microhemorrhage of PLEVA.³

Mycosis fungoides is a malignant lymphoproliferative disorder that is characterized by an indolent clinical course of persistent patches, plaques, or tumors of various sizes that often manifest in non–sun-exposed areas of the skin. Early stages of MF are difficult to detect histologically, but biopsies may show atypical lymphocytes with hyperchromatic, irregularly contoured nuclei arranged along the basal layer of the epidermis. Epidermal aggregates of atypical lymphocytes (also known as Pautrier microabscesses) are considered highly specific for MF. T-cell receptor and immunopathologic studies also are important adjuncts in the diagnosis of MF.⁴

Pemphigus foliaceus is an autoimmune blistering disease caused by antibodies directed against desmoglein 1, which is found in the granular layer of the epidermis. It manifests with a subtle onset of scattered crusted lesions in the seborrheic areas, such as the scalp, face, chest, and upper back. Histopathologic findings of early blisters may include acantholysis and dyskeratosis in the stratum granulosum as well as vacuolization of the granular layer. The blisters may coalesce into superficial bullae containing fibrin and neutrophils. Immunofluorescence studies that demonstrate intraepidermal C3 and IgG deposition are key to the diagnosis of pemphigus.⁵

Varicella (also known as chickenpox) manifests with crops of vesicles on an erythematous base in a centripetal distribution favoring the trunk and proximal extremities. It often is preceded by prodromal fever, malaise, and myalgia. Histopathologic evaluation of varicella is uncommon but may reveal acantholysis, multinucleation, and nuclear margination of keratinocytes. Viral culture or nucleic acid amplification testing of lesions can be used to verify the diagnosis.⁶

Most cases of PLEVA resolve without intervention.7 Treatment is directed at speeding recovery, providing symptomatic relief, and limiting permanent sequelae. Topical steroids often are used to alleviate inflammation and pruritus. Systemic antibiotics such as doxycycline, minocycline, and erythromycin have been used for their anti-inflammatory properties. Phototherapy of various wavelengths, including broadband and narrowband UVB as well as psoralen plus UVA, have led to improvements in affected patients. Refractory disease may warrant consideration of therapy with methotrexate, acitretin, dapsone, or cyclosporine.⁷

There have been rare reports of PLEVA evolving into its potentially lethal variant, febrile ulceronecrotic Mucha-Habermann disease, which is differentiated by the presence of systemic manifestations, including high fever, sore throat, diarrhea, central nervous system symptoms, abdominal pain, interstitial pneumonitis, splenomegaly, arthritis, sepsis, megaloblastic anemia, or conjunctival ulcers. The orogenital mucosa may be affected. Cutaneous lesions may rapidly progress to large, generalized, coalescent ulcers with necrotic crusts and vasculitic features on biopsy.8 Malignant transformation of PLEVA into LyP or MF rarely may occur and warrants continued follow-up of unresolved lesions.⁹

The Cutis Editorial Board is now accepting applications for the 2025 Resident Corner column. The Editorial Board will select 2 to 3 residents to serve as the Resident Corner columnists for 1 year. Articles are posted online only at www.mdedge.com/dermatology but will be referenced in Index Medicus. All applicants must be current residents and will be in residency throughout 2025.

For consideration, send your curriculum vitae along with a brief (not to exceed 500 words) statement of why you enjoy Cutis and what you can offer your fellow residents in contributing a monthly column.

A signed letter of recommendation from the Director of the dermatology residency program also should be supplied.

All materials should be submitted via email to Alicia Sonners ([email protected]) by November 1. The residents who are selected to write the column for the upcoming year will be notified by November 15.

We look forward to continuing to educate dermatology residents on topics that are most important to them!

The Cutis Editorial Board is now accepting applications for the 2025 Resident Corner column. The Editorial Board will select 2 to 3 residents to serve as the Resident Corner columnists for 1 year. Articles are posted online only at www.mdedge.com/dermatology but will be referenced in Index Medicus. All applicants must be current residents and will be in residency throughout 2025.

For consideration, send your curriculum vitae along with a brief (not to exceed 500 words) statement of why you enjoy Cutis and what you can offer your fellow residents in contributing a monthly column.

A signed letter of recommendation from the Director of the dermatology residency program also should be supplied.

All materials should be submitted via email to Alicia Sonners ([email protected]) by November 1. The residents who are selected to write the column for the upcoming year will be notified by November 15.

We look forward to continuing to educate dermatology residents on topics that are most important to them!

The Cutis Editorial Board is now accepting applications for the 2025 Resident Corner column. The Editorial Board will select 2 to 3 residents to serve as the Resident Corner columnists for 1 year. Articles are posted online only at www.mdedge.com/dermatology but will be referenced in Index Medicus. All applicants must be current residents and will be in residency throughout 2025.

For consideration, send your curriculum vitae along with a brief (not to exceed 500 words) statement of why you enjoy Cutis and what you can offer your fellow residents in contributing a monthly column.

A signed letter of recommendation from the Director of the dermatology residency program also should be supplied.

All materials should be submitted via email to Alicia Sonners ([email protected]) by November 1. The residents who are selected to write the column for the upcoming year will be notified by November 15.

We look forward to continuing to educate dermatology residents on topics that are most important to them!

To the Editor:
Crusted scabies (formerly known as Norwegian scabies) is a rare and highly contagious variant of scabies, in which the skin is infested with thousands to millions of Sarcoptes scabiei var hominis mites. We present a case of skin changes that were misdiagnosed as atopic dermatitis, seborrhea, xerosis, and drug eruption on initial presentation, which prompted treatment with a corticosteroid that inadvertently caused progression to crusted scabies.

A 79-year-old woman who uses a wheelchair presented to the clinic with skin changes that consisted of diffuse, severely pruritic, erythematous plaques on the head, neck, trunk, face, and extremities of 2 years’ duration. She had a medical history of hyperlipidemia, hypertension, and hyperglycemia, as well as a stroke that required hospitalization 2 years prior to the onset of the skin changes. She had no history of allergies.

Prior clinical diagnoses by primary care and dermatology included xerosis, atopic dermatitis, seborrhea, and drug eruption. She was treated with a mid-potency topical corticosteroid (triamcinolone acetonide cream 0.1%) twice daily and prednisone 40 mg once daily for 2- to 4-week courses over an 8-month period without reduction in symptoms.

Physical examination at the current presentation revealed golden, crusted, fine, powdery but slightly sticky flakes that spread diffusely across the entire body and came off in crumbles with a simple touch. These widespread crusts were easily visible on clothing. There was underlying diffuse erythema beneath the flaking skin on the trunk and proximal extremities. The scale and shedding skin laid in piles on the patient’s lap and resembled brown sugar (Figure 1). The patient also reported decreased hand function and dexterity due to the yellowbrown, thick, crusty plaques that had developed on both the palmar and dorsal sides of the hands (Figure 2). Erythematous plaques on the scalp, forehead, and inner ears resembled seborrhea (Figure 3). Pruritus severity was rated by the patient as 10 of 10, and she scratched her skin the entire time she was in the clinic. The patient was emotional and stated that she had not been able to sleep due to the discomfort. We suspected scabies, and the patient was reassured to learn that it could be confirmed with a simple skin scrape test.

The crusted lesions on the patient's hands were scraped with a #15-blade scalpel, and a routine potassium hydroxide mount was performed. The skin scrapings were placed on a slide with a drop of 10% potassium hydroxide and observed under low-power (×10) and high-power (×40) microscopy, which revealed thousands of mites and eggs (along with previously hatched eggs) (Figure 4) and quickly confirmed a diagnosis of crusted scabies.an extremely contagious form of scabies seen in older patients with compromised immune systems, malnutrition, or disabilities. The patient was prescribed oral ivermectin (3 mg dosed at 200 μg/kg of body weight) and topical permethrin 5%, neither of which she took, as she died of a COVID-19 infection complication 3 days after this diagnostic clinic visit.

Classic and crusted scabies are both caused by infestation of the Sarcoptes scabiei var hominis mite. Classic scabies is a result of an infestation of a small number of mites (commonly 5–15 mites), while crusted scabies is due to hyperinfestation by as many as millions of mites, the latter often requiring more aggressive treatment. The mites are first transmitted to humans by either skin-toskin contact or fomites on bedding and clothing. The scabies mite undergoes 4 life cycle stages: egg, larvae, nymph, and adult. Once female mites are transmitted, they burrow under the skin and lay 2 to 3 eggs per day. The eggs hatch within 3 to 4 days, after which the larvae migrate to the skin surface. The larval stage lasts for 3 to 4 days, during which the larvae burrow into the stratum corneum to create molting pouches, until they molt into slightly larger nymphs. Nymphs can be found in hair follicles or molting pouches until they further molt within 3 to 4 days into adults, which are round, saclike mites. The adult male and female mites then mate, leaving the female fertile for the rest of her 1- to 2-month lifespan. Impregnated female mites traverse the skin surface in search of a burrow site, using the pulvilli on the anterior aspect of 2 legs to hold onto the skin. Once burrowed, the female mite continues to lay eggs for the rest of her life, with approximately 10% of her eggs resulting in adult mites. Male mites feed in shallow pits of the skin until they find a female burrow site for mating.¹ This continuous life cycle of the scabies mite gives rise to highly transmissible, pruritic skin excoriations, as demonstrated in our patient.

The skin has a relatively late inflammatory and adaptive immune response to scabies, typically occurring 4 to 6 weeks after the initial infestation.² This delayed inflammatory response and onset of symptoms may be due to the scabies mite’s ability to alter aspects of the host’s immune response, which differs in classic vs crusted scabies. In classic scabies, there is a predominance of CD4+ T cells in the dermis and minimal CD8+ T cells. The opposite is true in crusted scabies— there is an overwhelming infiltration of CD8+ T cells and minimal CD4+ T cells.³ The CD8+ T-cell predominance in crusted scabies is hypothesized to be the cause of keratinocyte apoptosis, resulting in epidermal hyperproliferation. Keratinocyte apoptosis also secretes cytokines, which may lead to the immunologic targeting of healthy skin cells. The damage of healthy dermal cells contributes to the inability of the skin’s immune system to mount an effective response, allowing the parasite to grow uncontrollably in patients with crusted scabies.⁴

This ineffective immune response is further exacerbated by corticosteroids, which are commonly prescribed for pruritus experienced by patients with scabies infestations. The mechanism of action of corticosteroids is the production of anti-inflammatory, antimitotic, and immunosuppressive effects.⁵ Because the integumentary immune system is imbalanced during crusted scabies infestation, the immunosuppressive mechanism of oral and topical corticosteroids further reduces the cellular immune response to scabies. The flourishing of the scabies mites along with keratinocyte apoptosis⁴ results in the development of hyperkeratotic skin crusting, most frequently on the palms, soles, arms, and legs. Risk factors for crusted scabies include immunosuppression, hospitalization, crowded living conditions, and poor hygiene, though no known risk factors were documented in up to 42% (33/78) of patients with crusted scabies in one study.⁶

Patients with crusted scabies typically present with generalized, poorly defined, erythematous, fissured plaques covered by scaling and crusts. Plaques on bony prominences such as finger articulations and elbows may have a thick verrucous aspect.¹ Skin flaking that resembles brown sugar—a mixture of white sugar and molasses—is a clue to the diagnosis of crusted scabies. Brown sugar has a slightly sandy and sticky texture that ranges in color from very light brown to very dark brown. When present, flakes always appears slightly lighter than the patient’s skin tone. Although skin burrows are pathognomonic and clinically recognizable features of scabies, these burrows can be disguised by lesions, such as the hyperkeratotic plaques seen in our patient. The lesions may or may not be associated with pruritus, which may occur only at night, and bacterial superinfection has been reported in severe cases of crusted scabies,⁷ as scratching can cause sores, which may lead to infection. In severe cases, the constant scratching could lead to sepsis if the infection enters the bloodstream.⁸ Another symptom of scabies is a rash that causes small bumps that tend to form in a line, resembling small bites, hives, or pimples, and scaly plaques can lead to misdiagnosis as atopic dermatitis.

Treatment often is delayed due to misdiagnosis, as seen in our patient. Common misdiagnoses include atopic dermatitis, pityriasis rosea, systemic lupus erythematosus, bullous pemphigoid, lichen planus, pediculosis corporis, seborrheic scalp dermatitis, and adverse drug reactions.⁹ Patients with extensive infestations of crusted scabies should be treated with a 4-week course of permethrin cream 5% daily for 1 week, then twice per week until resolved, and oral ivermectin 200 μg/kg dosed 1 week apart for up to 4 weeks, if needed.¹ Topical permethrin works by producing a selective neurotoxic effect on invertebrates such as scabies mites, which disrupts the function of voltage-gated sodium channels, thereby paralyzing the adult mites to halt the spread of infestation. However, treatment with topical medications can be difficult due to the thick crusts that have formed, which make it more challenging for the skin to properly absorb the treatment. Additionally, surgical debridement as an adjunct procedure has been done to improve the effectiveness of topical medications by removing all the mites in skin.¹⁰ On the other hand, the mechanism in which ivermectin treats scabies infestations is poorly understood. Current research suggests that ivermectin works by causing persistent opening of pH-gated chloride channels in scabies mites.¹¹ There is emerging concern for drug resistance to these scabicides,¹² revealing a need for further research of treatment options.

Patients with crusted scabies can have an extremely large number of mites (up to 2 million), making them more infectious than patients with classic scabies.¹³ As a result, it is imperative to reduce environmental transmission and risk for reinfection with mites during treatment. Because crusted scabies is transmitted by prolonged skinto- skin contact or by contact with personal items of an infected person (eg, bedding, clothing), treatment guidelines require all clothing, bedding, and towels of a patient with scabies to be machine-washed and dried with hot water and hot dryer cycles. If an item cannot be washed, it should be stored in a sealed plastic bag for 1 week, as scabies mites cannot survive more than 2 to 3 days away from their host of human skin.¹³ Treatment of close contacts of patients with scabies is recommended, as well as for those in endemic areas or closed communities, such as nursing homes or jails.

To the Editor:
Crusted scabies (formerly known as Norwegian scabies) is a rare and highly contagious variant of scabies, in which the skin is infested with thousands to millions of Sarcoptes scabiei var hominis mites. We present a case of skin changes that were misdiagnosed as atopic dermatitis, seborrhea, xerosis, and drug eruption on initial presentation, which prompted treatment with a corticosteroid that inadvertently caused progression to crusted scabies.

A 79-year-old woman who uses a wheelchair presented to the clinic with skin changes that consisted of diffuse, severely pruritic, erythematous plaques on the head, neck, trunk, face, and extremities of 2 years’ duration. She had a medical history of hyperlipidemia, hypertension, and hyperglycemia, as well as a stroke that required hospitalization 2 years prior to the onset of the skin changes. She had no history of allergies.

Prior clinical diagnoses by primary care and dermatology included xerosis, atopic dermatitis, seborrhea, and drug eruption. She was treated with a mid-potency topical corticosteroid (triamcinolone acetonide cream 0.1%) twice daily and prednisone 40 mg once daily for 2- to 4-week courses over an 8-month period without reduction in symptoms.

Physical examination at the current presentation revealed golden, crusted, fine, powdery but slightly sticky flakes that spread diffusely across the entire body and came off in crumbles with a simple touch. These widespread crusts were easily visible on clothing. There was underlying diffuse erythema beneath the flaking skin on the trunk and proximal extremities. The scale and shedding skin laid in piles on the patient’s lap and resembled brown sugar (Figure 1). The patient also reported decreased hand function and dexterity due to the yellowbrown, thick, crusty plaques that had developed on both the palmar and dorsal sides of the hands (Figure 2). Erythematous plaques on the scalp, forehead, and inner ears resembled seborrhea (Figure 3). Pruritus severity was rated by the patient as 10 of 10, and she scratched her skin the entire time she was in the clinic. The patient was emotional and stated that she had not been able to sleep due to the discomfort. We suspected scabies, and the patient was reassured to learn that it could be confirmed with a simple skin scrape test.

The crusted lesions on the patient's hands were scraped with a #15-blade scalpel, and a routine potassium hydroxide mount was performed. The skin scrapings were placed on a slide with a drop of 10% potassium hydroxide and observed under low-power (×10) and high-power (×40) microscopy, which revealed thousands of mites and eggs (along with previously hatched eggs) (Figure 4) and quickly confirmed a diagnosis of crusted scabies.an extremely contagious form of scabies seen in older patients with compromised immune systems, malnutrition, or disabilities. The patient was prescribed oral ivermectin (3 mg dosed at 200 μg/kg of body weight) and topical permethrin 5%, neither of which she took, as she died of a COVID-19 infection complication 3 days after this diagnostic clinic visit.

Classic and crusted scabies are both caused by infestation of the Sarcoptes scabiei var hominis mite. Classic scabies is a result of an infestation of a small number of mites (commonly 5–15 mites), while crusted scabies is due to hyperinfestation by as many as millions of mites, the latter often requiring more aggressive treatment. The mites are first transmitted to humans by either skin-toskin contact or fomites on bedding and clothing. The scabies mite undergoes 4 life cycle stages: egg, larvae, nymph, and adult. Once female mites are transmitted, they burrow under the skin and lay 2 to 3 eggs per day. The eggs hatch within 3 to 4 days, after which the larvae migrate to the skin surface. The larval stage lasts for 3 to 4 days, during which the larvae burrow into the stratum corneum to create molting pouches, until they molt into slightly larger nymphs. Nymphs can be found in hair follicles or molting pouches until they further molt within 3 to 4 days into adults, which are round, saclike mites. The adult male and female mites then mate, leaving the female fertile for the rest of her 1- to 2-month lifespan. Impregnated female mites traverse the skin surface in search of a burrow site, using the pulvilli on the anterior aspect of 2 legs to hold onto the skin. Once burrowed, the female mite continues to lay eggs for the rest of her life, with approximately 10% of her eggs resulting in adult mites. Male mites feed in shallow pits of the skin until they find a female burrow site for mating.¹ This continuous life cycle of the scabies mite gives rise to highly transmissible, pruritic skin excoriations, as demonstrated in our patient.

The skin has a relatively late inflammatory and adaptive immune response to scabies, typically occurring 4 to 6 weeks after the initial infestation.² This delayed inflammatory response and onset of symptoms may be due to the scabies mite’s ability to alter aspects of the host’s immune response, which differs in classic vs crusted scabies. In classic scabies, there is a predominance of CD4+ T cells in the dermis and minimal CD8+ T cells. The opposite is true in crusted scabies— there is an overwhelming infiltration of CD8+ T cells and minimal CD4+ T cells.³ The CD8+ T-cell predominance in crusted scabies is hypothesized to be the cause of keratinocyte apoptosis, resulting in epidermal hyperproliferation. Keratinocyte apoptosis also secretes cytokines, which may lead to the immunologic targeting of healthy skin cells. The damage of healthy dermal cells contributes to the inability of the skin’s immune system to mount an effective response, allowing the parasite to grow uncontrollably in patients with crusted scabies.⁴

This ineffective immune response is further exacerbated by corticosteroids, which are commonly prescribed for pruritus experienced by patients with scabies infestations. The mechanism of action of corticosteroids is the production of anti-inflammatory, antimitotic, and immunosuppressive effects.⁵ Because the integumentary immune system is imbalanced during crusted scabies infestation, the immunosuppressive mechanism of oral and topical corticosteroids further reduces the cellular immune response to scabies. The flourishing of the scabies mites along with keratinocyte apoptosis⁴ results in the development of hyperkeratotic skin crusting, most frequently on the palms, soles, arms, and legs. Risk factors for crusted scabies include immunosuppression, hospitalization, crowded living conditions, and poor hygiene, though no known risk factors were documented in up to 42% (33/78) of patients with crusted scabies in one study.⁶

Patients with crusted scabies typically present with generalized, poorly defined, erythematous, fissured plaques covered by scaling and crusts. Plaques on bony prominences such as finger articulations and elbows may have a thick verrucous aspect.¹ Skin flaking that resembles brown sugar—a mixture of white sugar and molasses—is a clue to the diagnosis of crusted scabies. Brown sugar has a slightly sandy and sticky texture that ranges in color from very light brown to very dark brown. When present, flakes always appears slightly lighter than the patient’s skin tone. Although skin burrows are pathognomonic and clinically recognizable features of scabies, these burrows can be disguised by lesions, such as the hyperkeratotic plaques seen in our patient. The lesions may or may not be associated with pruritus, which may occur only at night, and bacterial superinfection has been reported in severe cases of crusted scabies,⁷ as scratching can cause sores, which may lead to infection. In severe cases, the constant scratching could lead to sepsis if the infection enters the bloodstream.⁸ Another symptom of scabies is a rash that causes small bumps that tend to form in a line, resembling small bites, hives, or pimples, and scaly plaques can lead to misdiagnosis as atopic dermatitis.

Treatment often is delayed due to misdiagnosis, as seen in our patient. Common misdiagnoses include atopic dermatitis, pityriasis rosea, systemic lupus erythematosus, bullous pemphigoid, lichen planus, pediculosis corporis, seborrheic scalp dermatitis, and adverse drug reactions.⁹ Patients with extensive infestations of crusted scabies should be treated with a 4-week course of permethrin cream 5% daily for 1 week, then twice per week until resolved, and oral ivermectin 200 μg/kg dosed 1 week apart for up to 4 weeks, if needed.¹ Topical permethrin works by producing a selective neurotoxic effect on invertebrates such as scabies mites, which disrupts the function of voltage-gated sodium channels, thereby paralyzing the adult mites to halt the spread of infestation. However, treatment with topical medications can be difficult due to the thick crusts that have formed, which make it more challenging for the skin to properly absorb the treatment. Additionally, surgical debridement as an adjunct procedure has been done to improve the effectiveness of topical medications by removing all the mites in skin.¹⁰ On the other hand, the mechanism in which ivermectin treats scabies infestations is poorly understood. Current research suggests that ivermectin works by causing persistent opening of pH-gated chloride channels in scabies mites.¹¹ There is emerging concern for drug resistance to these scabicides,¹² revealing a need for further research of treatment options.

Patients with crusted scabies can have an extremely large number of mites (up to 2 million), making them more infectious than patients with classic scabies.¹³ As a result, it is imperative to reduce environmental transmission and risk for reinfection with mites during treatment. Because crusted scabies is transmitted by prolonged skinto- skin contact or by contact with personal items of an infected person (eg, bedding, clothing), treatment guidelines require all clothing, bedding, and towels of a patient with scabies to be machine-washed and dried with hot water and hot dryer cycles. If an item cannot be washed, it should be stored in a sealed plastic bag for 1 week, as scabies mites cannot survive more than 2 to 3 days away from their host of human skin.¹³ Treatment of close contacts of patients with scabies is recommended, as well as for those in endemic areas or closed communities, such as nursing homes or jails.

To the Editor:
Crusted scabies (formerly known as Norwegian scabies) is a rare and highly contagious variant of scabies, in which the skin is infested with thousands to millions of Sarcoptes scabiei var hominis mites. We present a case of skin changes that were misdiagnosed as atopic dermatitis, seborrhea, xerosis, and drug eruption on initial presentation, which prompted treatment with a corticosteroid that inadvertently caused progression to crusted scabies.

A 79-year-old woman who uses a wheelchair presented to the clinic with skin changes that consisted of diffuse, severely pruritic, erythematous plaques on the head, neck, trunk, face, and extremities of 2 years’ duration. She had a medical history of hyperlipidemia, hypertension, and hyperglycemia, as well as a stroke that required hospitalization 2 years prior to the onset of the skin changes. She had no history of allergies.

Prior clinical diagnoses by primary care and dermatology included xerosis, atopic dermatitis, seborrhea, and drug eruption. She was treated with a mid-potency topical corticosteroid (triamcinolone acetonide cream 0.1%) twice daily and prednisone 40 mg once daily for 2- to 4-week courses over an 8-month period without reduction in symptoms.

Physical examination at the current presentation revealed golden, crusted, fine, powdery but slightly sticky flakes that spread diffusely across the entire body and came off in crumbles with a simple touch. These widespread crusts were easily visible on clothing. There was underlying diffuse erythema beneath the flaking skin on the trunk and proximal extremities. The scale and shedding skin laid in piles on the patient’s lap and resembled brown sugar (Figure 1). The patient also reported decreased hand function and dexterity due to the yellowbrown, thick, crusty plaques that had developed on both the palmar and dorsal sides of the hands (Figure 2). Erythematous plaques on the scalp, forehead, and inner ears resembled seborrhea (Figure 3). Pruritus severity was rated by the patient as 10 of 10, and she scratched her skin the entire time she was in the clinic. The patient was emotional and stated that she had not been able to sleep due to the discomfort. We suspected scabies, and the patient was reassured to learn that it could be confirmed with a simple skin scrape test.

The crusted lesions on the patient's hands were scraped with a #15-blade scalpel, and a routine potassium hydroxide mount was performed. The skin scrapings were placed on a slide with a drop of 10% potassium hydroxide and observed under low-power (×10) and high-power (×40) microscopy, which revealed thousands of mites and eggs (along with previously hatched eggs) (Figure 4) and quickly confirmed a diagnosis of crusted scabies.an extremely contagious form of scabies seen in older patients with compromised immune systems, malnutrition, or disabilities. The patient was prescribed oral ivermectin (3 mg dosed at 200 μg/kg of body weight) and topical permethrin 5%, neither of which she took, as she died of a COVID-19 infection complication 3 days after this diagnostic clinic visit.

Classic and crusted scabies are both caused by infestation of the Sarcoptes scabiei var hominis mite. Classic scabies is a result of an infestation of a small number of mites (commonly 5–15 mites), while crusted scabies is due to hyperinfestation by as many as millions of mites, the latter often requiring more aggressive treatment. The mites are first transmitted to humans by either skin-toskin contact or fomites on bedding and clothing. The scabies mite undergoes 4 life cycle stages: egg, larvae, nymph, and adult. Once female mites are transmitted, they burrow under the skin and lay 2 to 3 eggs per day. The eggs hatch within 3 to 4 days, after which the larvae migrate to the skin surface. The larval stage lasts for 3 to 4 days, during which the larvae burrow into the stratum corneum to create molting pouches, until they molt into slightly larger nymphs. Nymphs can be found in hair follicles or molting pouches until they further molt within 3 to 4 days into adults, which are round, saclike mites. The adult male and female mites then mate, leaving the female fertile for the rest of her 1- to 2-month lifespan. Impregnated female mites traverse the skin surface in search of a burrow site, using the pulvilli on the anterior aspect of 2 legs to hold onto the skin. Once burrowed, the female mite continues to lay eggs for the rest of her life, with approximately 10% of her eggs resulting in adult mites. Male mites feed in shallow pits of the skin until they find a female burrow site for mating.¹ This continuous life cycle of the scabies mite gives rise to highly transmissible, pruritic skin excoriations, as demonstrated in our patient.

The skin has a relatively late inflammatory and adaptive immune response to scabies, typically occurring 4 to 6 weeks after the initial infestation.² This delayed inflammatory response and onset of symptoms may be due to the scabies mite’s ability to alter aspects of the host’s immune response, which differs in classic vs crusted scabies. In classic scabies, there is a predominance of CD4+ T cells in the dermis and minimal CD8+ T cells. The opposite is true in crusted scabies— there is an overwhelming infiltration of CD8+ T cells and minimal CD4+ T cells.³ The CD8+ T-cell predominance in crusted scabies is hypothesized to be the cause of keratinocyte apoptosis, resulting in epidermal hyperproliferation. Keratinocyte apoptosis also secretes cytokines, which may lead to the immunologic targeting of healthy skin cells. The damage of healthy dermal cells contributes to the inability of the skin’s immune system to mount an effective response, allowing the parasite to grow uncontrollably in patients with crusted scabies.⁴

This ineffective immune response is further exacerbated by corticosteroids, which are commonly prescribed for pruritus experienced by patients with scabies infestations. The mechanism of action of corticosteroids is the production of anti-inflammatory, antimitotic, and immunosuppressive effects.⁵ Because the integumentary immune system is imbalanced during crusted scabies infestation, the immunosuppressive mechanism of oral and topical corticosteroids further reduces the cellular immune response to scabies. The flourishing of the scabies mites along with keratinocyte apoptosis⁴ results in the development of hyperkeratotic skin crusting, most frequently on the palms, soles, arms, and legs. Risk factors for crusted scabies include immunosuppression, hospitalization, crowded living conditions, and poor hygiene, though no known risk factors were documented in up to 42% (33/78) of patients with crusted scabies in one study.⁶

Patients with crusted scabies typically present with generalized, poorly defined, erythematous, fissured plaques covered by scaling and crusts. Plaques on bony prominences such as finger articulations and elbows may have a thick verrucous aspect.¹ Skin flaking that resembles brown sugar—a mixture of white sugar and molasses—is a clue to the diagnosis of crusted scabies. Brown sugar has a slightly sandy and sticky texture that ranges in color from very light brown to very dark brown. When present, flakes always appears slightly lighter than the patient’s skin tone. Although skin burrows are pathognomonic and clinically recognizable features of scabies, these burrows can be disguised by lesions, such as the hyperkeratotic plaques seen in our patient. The lesions may or may not be associated with pruritus, which may occur only at night, and bacterial superinfection has been reported in severe cases of crusted scabies,⁷ as scratching can cause sores, which may lead to infection. In severe cases, the constant scratching could lead to sepsis if the infection enters the bloodstream.⁸ Another symptom of scabies is a rash that causes small bumps that tend to form in a line, resembling small bites, hives, or pimples, and scaly plaques can lead to misdiagnosis as atopic dermatitis.

Treatment often is delayed due to misdiagnosis, as seen in our patient. Common misdiagnoses include atopic dermatitis, pityriasis rosea, systemic lupus erythematosus, bullous pemphigoid, lichen planus, pediculosis corporis, seborrheic scalp dermatitis, and adverse drug reactions.⁹ Patients with extensive infestations of crusted scabies should be treated with a 4-week course of permethrin cream 5% daily for 1 week, then twice per week until resolved, and oral ivermectin 200 μg/kg dosed 1 week apart for up to 4 weeks, if needed.¹ Topical permethrin works by producing a selective neurotoxic effect on invertebrates such as scabies mites, which disrupts the function of voltage-gated sodium channels, thereby paralyzing the adult mites to halt the spread of infestation. However, treatment with topical medications can be difficult due to the thick crusts that have formed, which make it more challenging for the skin to properly absorb the treatment. Additionally, surgical debridement as an adjunct procedure has been done to improve the effectiveness of topical medications by removing all the mites in skin.¹⁰ On the other hand, the mechanism in which ivermectin treats scabies infestations is poorly understood. Current research suggests that ivermectin works by causing persistent opening of pH-gated chloride channels in scabies mites.¹¹ There is emerging concern for drug resistance to these scabicides,¹² revealing a need for further research of treatment options.

Patients with crusted scabies can have an extremely large number of mites (up to 2 million), making them more infectious than patients with classic scabies.¹³ As a result, it is imperative to reduce environmental transmission and risk for reinfection with mites during treatment. Because crusted scabies is transmitted by prolonged skinto- skin contact or by contact with personal items of an infected person (eg, bedding, clothing), treatment guidelines require all clothing, bedding, and towels of a patient with scabies to be machine-washed and dried with hot water and hot dryer cycles. If an item cannot be washed, it should be stored in a sealed plastic bag for 1 week, as scabies mites cannot survive more than 2 to 3 days away from their host of human skin.¹³ Treatment of close contacts of patients with scabies is recommended, as well as for those in endemic areas or closed communities, such as nursing homes or jails.

Melasma (also known as chloasma faciei) is a common chronic skin disorder that results in well-demarcated, hyperpigmented, tan to dark patches that mostly appear in sun-exposed areas such as the face and neck and sometimes the arms. The exact prevalence or incidence is not known but is estimated to be 1% to 50% overall depending on the ethnic population and geographic location.^1,2 Melasma predominantly affects women, but research has shown that approximately 10% to 20% of men are affected by this condition.^3,4 Although melasma can affect patients of all skin types, it primarily affects those with darker skin tones.⁵ The groups most often affected are women of Black, Hispanic, Middle Eastern, and Southeast Asian ethnicity. Although the pathogenesis is complex and not fully understood, multiple pathways and etiologies have been theorized to cause melasma. Potential causes include exposure to UV radiation, oral contraceptives, hormonal changes, medications, thyroid dysfunction, genetics, and pregnancy.^6,7 Cytokines and growth factors, including adipokine and angiopoietin, synthesized by sebaceous glands play a role in the pathogenic mechanism of melasma. Cytokines and growth factors are hypothesized to modulate the function of melanocytes.⁸ Both melanocytes and sebocytes are controlled by α–melanocyte-stimulating hormone. Therefore, overexpression of α–melanocyte-stimulating hormone will result in overproduction of these 2 cell types, resulting in melasma. Melasma can be classified into 4 subtypes using Wood lamp examination: epidermal, dermal, mixed, or indeterminate.³ Furthermore, melasma is divided into subgroups based on the location: malar region, mandibular region, and centrofacial patch pattern.^9,10 The involvement of sebaceous glands in the pathogenesis of melasma may explain the predilection for the centrofacial region, which is the most common pattern.

The severity of melasma can be assessed using the melasma area and severity index (MASI), which is calculated by subjective assessment of 3 main factors: (1) facial area of involvement; (2) darkness of affected region; and (3) homogeneity, with the extent of melasma indicated by a score ranging from 0 to 48.¹¹ The modified MASI (mMASI) subsequently was introduced to assist with assessing the severity of melasma and creating distinct ranges for mild, moderate, and severe cases, ranging from 0 (mild) to 24 (severe).¹² Both indices are used in research to assess the improvement of melasma with treatment.

Patients with melasma report a decrease in quality of life, increased emotional stress, and lower self-esteem due to cosmesis.¹³ Treatment of melasma can be highly challenging and often is complicated by relapsing. Historically, the treatment of melasma has included the use of chemical lightening agents. Additional treatment options include the use of lasers and complex chemical peels,^9,10 but these interventions may result in adverse outcomes for individuals with darker skin tones. The current gold-standard treatment is topical hydroquinone and broad-spectrum sunscreen. Although hydroquinone is effective in the treatment of melasma, relapse is common. The goal of melasma management is not only to treat acute hyperpigmentation but also to prevent relapse. Other therapies that currently are being explored for the clinically sustained treatment of melasma include tranexamic acid (TXA)(trans-4-[aminomethyl]cyclohexanecarboxylic acid),^9,10 an antifibrinolytic agent routinely used to prevent blood loss during surgery and in the management of menorrhagia. It is a synthetic derivative of lysine and serves as a potent plasmin inhibitor by blocking the lysine-binding sites of plasminogen molecules, thus preventing the conversion of plasminogen to plasmin. It also prevents fibrinolysis and blood loss.

In addition to its hemostatic properties, TXA has been found to have hypopigmentation properties.^14,15 Plasminogen also can be found in human epidermal basal cells and human keratinocytes, and it is postulated that TXA’s interaction with these cells explains its hypopigmentation properties. Both UV radiation and hormones activate plasminogen into plasmin, resulting in the activation of tyrosinase and melanogenesis.^14,15 Tranexamic acid is postulated to inhibit the keratinocyte-plasminogen pathway, thus leading to the inhibition of UV-induced and hormone-induced pigmentation. Also, TXA serves as a competitive inhibitor for tyrosinase due to its structural similarity to tyrosine.¹⁵ The combination of these 2 mechanisms contributes to the skin-lightening effects of TXA, making it a potential treatment for melasma.

Furthermore, the use of microneedling is being explored as a treatment option for melasma. Microneedling creates microscopic punctures in the skin using tiny needles, resulting in a wound-healing response and skin resurfacing. The microneedling technique is utilized to create small holes in the skin, with needle depths that can be adjusted from 0.5 to 3.5 mm to target different layers of the dermis and allow for discreet application of TXA.¹⁶ We sought to look at the current literature on the use and effectiveness of microneedling in combination with TXA to treat melasma and prevent relapse.

Methods

A systematic review was performed of PubMed articles indexed for MEDLINE and Embase in November 2021 to compile available articles that studied TXA and microneedling as a treatment for melasma. The PubMed search terms were (melasma) AND (microneedling* OR ‘tranexamic acid’ OR TXA or TA). The Embase search terms were (cholasma OR melasma) AND (tranexamic acid OR TXA) AND (microneedling)(Figure). The search was then limited to ”randomized controlled trial” and ”clinical trial” in English-language journals. Duplicates were excluded. After thorough evaluation, articles that discussed the use of TXA in combination with treatment options other than microneedling also were excluded.

Results

The literature search yielded a total of 12 articles that assessed the effectiveness of TXA and microneedling for the treatment of melasma (Table).^17-28 Several articles concluded that TXA was equally effective at reducing melasma lesions when compared with the standard treatment of hydroquinone. Some of the reviewed articles also demonstrated the effectiveness of microneedling in improving melasma lesions as a stand-alone treatment. These studies highlighted the enhanced efficacy of the combined treatment of TXA and microneedling compared with their individual uses.^17-28

Comment

Melasma is a common chronic hyperpigmentation disorder, making its treatment clinically challenging. Many patients experience symptom relapses, and limited effective treatment options make achieving complete clearance difficult, underscoring the need for improved therapeutic approaches. Recently, researchers have explored alternative treatments to address the challenges of melasma management. Tranexamic acid is an antifibrinolytic used to prevent blood loss and has emerged as a potential treatment for melasma. Similarly, microneedling—a technique in which multiple punctures are made in the skin to activate and stimulate wound healing and skin rejuvenation—shows promise for melasma.

Oral TXA for Melasma—Oral TXA has been shown to reduce melasma lesions. Del Rosario et al¹⁷ recruited 44 women (39 of whom completed the study) with moderate to severe melasma and randomized them into 2 groups: oral TXA and placebo. This study demonstrated a 49% reduction in the mMASI score in all participants taking oral TXA (250 mg twice daily [BID]) compared with an 18% reduction in the control group (placebo capsule BID) after 3 months of treatment. In patients with moderate and severe melasma, 45% and 51% mMASI score reductions were reported in the treatment group, respectively, vs 16% and 19% score reductions in placebo group, respectively. These researchers concluded that oral TXA may be effective at treating moderate to severe melasma. Although patients with severe melasma had a better response to treatment, their improvement was not sustained compared with patients with moderate melasma after a 3-month posttreatment follow-up.¹⁷

Microneedling Plus TXA for Melasma—Microneedling alone has been shown to be effective for melasma. El Attar et al¹⁸ conducted a split-face study of microneedling (1.5-mm depth) plus topical TXA (0.5 mL)(right side of the face[treatment arm]) compared with microneedling (1.5-mm depth) plus topical vitamin C (0.5 mL)(left side of the face [control group]) in 20 women with melasma. The sessions were repeated every 2 weeks for a total of 6 sessions. Although researchers found no statistically significant differences between the 2 treatment sides, microneedling plus TXA showed a slight advantage over microneedling plus vitamin C in dermoscopic examination. Both sides showed improvement in pigmented lesions, but vitamin C–treated lesions did not show an improvement in vascularity vs TXA.¹⁸

Saleh et al¹⁹ further showed that combination treatment with microneedling and TXA may improve clinical outcomes better than microneedling alone. Their study demonstrated a reduction in MASI score that was significantly higher in the combination treatment group compared with the microneedling alone group (P=.001). There was a significant reduction in melanoma antigen recognized by T cells 1 (MART-1)–positive cells in the combination treatment group compared with the microneedling alone group (P=.001). Lastly, combined therapy improved melasma patches better than microneedling alone.¹⁹

Xu et al²⁰ conducted a split-face study (N=28) exploring the effectiveness of transdermal application of topical TXA using a microarray pen with microneedles (vibration at 3000×/min) plus topical TXA on one side of the face, while the other side received only topical TXA as a control. After 12 weeks of treatment, combination therapy with microneedling and TXA decreased brown spot scores, lowered melanin index (MI) values, improved blinded physician assessment, and improved patient satisfaction vs TXA therapy alone.²⁰

Kaur et al²¹ conducted a split-face, randomized, controlled trial of microneedling (1-mm depth) with TXA solution 10% vs microneedling (1-mm depth) with distilled water alone for 8 weeks (N=40). They graded participant responses to treatment using reductions in mMASI scores¹² at every 2 weeks of follow-up (no response, minimal or poor response=0%–25%; partial or fair response=26%–50%; good response=51%–75%; and excellent response=>75%). They reported an overall reduction in mMASI scores for both the treatment side and the control side in all participants, showing a 65.92% improvement in mean mMASI scores on the treatment side vs 20.75% improvement on the control side at week 8. Both sides showed statistically significant reductions in mean mMASI scores (P<.05). Clinically, 40% (16/40) of participants showed an excellent response to combined treatment compared with 0% (0/40) to microneedling alone. Overall, patient satisfaction was similar across both groups. This study demonstrated that microneedling alone improves melasma, but a combination of microneedling plus TXA showed a better clinical reduction in melasma. However, the researchers did not follow up with participants posttreatment, so it remains unclear if the improved clinical outcomes were sustained long-term.²¹

Ebrahim et al²² reported that the combination of 0.5 mL TXA (4 mg/mL) and microneedling (0.25- to 1-mm depth) was effective for melasma. Although there was improvement within microneedling and TXA, the study also showed that intradermal injection of TXA was significant in reducing mean mMASI scores and improving melasma (P<.001). The reduction in mMASI scores for the group receiving intradermal injections of TXA (left side; 74.8% reduction in mean mMASI score) vs the group receiving microneedling application of TXA (right side; 73.6% reduction in mean mMASI score) was not statistically significant. These findings suggest that the mode of TXA application may not be critical in determining clinical responses to TXA treatment. Although there was no reported statistically significant difference in clinical outcomes between the 2 treatments, patient satisfaction was higher on the microneedling side. Only 8 of 50 participants (16%) experienced recurrence 3 months posttreatment.²²

Saki et al²³ compared the efficacy of topical hydroquinone (2%) to intradermal TXA injections in treating melasma. They found intradermal TXA injections to be a clinically effective mode of treatment.²³

Sharma et al²⁴ explored the efficacy and safety of oral TXA by randomly assigning 100 Indian patients (20 of whom withdrew before study completion) with melasma into 2 groups: group A received TXA 250 mg twice daily, and group B received intradermal microinjections of TXA (4 mg/mL) every 4 weeks. The MASI scores were assessed at 4-week intervals for a total of 12 weeks. There was a decrease in MASI scores in both groups, and there was no statistically significant difference in mean percentage reduction in MASI scores between the 2 routes of drug administration, further suggesting the effectiveness of TXA independent of administration route. Two patients in group A relapsed at 24 weeks, and there were no relapses in group B, which may suggest a minimal superiority of TXA plus microneedling at providing more sustainable results compared with oral TXA alone. A notable limitation of this study was a high dropout rate as well as lack of long-term follow-up with participants, limiting the generalizability of the conclusions.²⁴

Cassiano et al²⁵ assigned 64 women with melasma to 1 of 3 treatment groups or a control group to compare the effectiveness of microneedling (M group: 1.5 mm; 2 sessions), oral TXA (T group: 250 mg/d twice daily for 60 days), and a combination of microneedling (2 sessions) and oral TXA (MT group: 250 mg/d twice daily for 60 days)with placebo for clinically reducing melasma lesions. The intervention period was 60 days followed by a 60-day maintenance phase for a total study period of 120 days. The researchers evaluated mMASI scores, quality of life, and difference in colorimetric luminosity. All treatment groups showed a reduction in mMASI scores at both 30 days and 60 days, indicating improved melasma severity. The MT and T groups had more significant improvement at 30 days compared with the control group (P<.03), suggesting that microneedling plus TXA and TXA alone promote faster improvement in melasma lesions. By 60 days, the M, T, and MT groups outperformed the control group, with no significant differences between the M, T, and MT groups. However, at the 120-day maintenance follow-up, the T group did not maintain its improvement compared with the control group. The M and MT groups showed no significance difference in effectiveness at 120 days, suggesting that microneedling may promote less frequent relapse and sustained remission compared to TXA alone.²⁵

Hydroquinone for Melasma—Additional studies on the use of TXA treatments show that TXA may be an equally effective alternative to the standard use of hydroquinone treatment. Shamsi Meymandi et al²⁶ did not find a statistically significant difference in treatment with TXA plus microneedling vs the standard regimen of hydroquinone. More importantly, patient and physician satisfaction assessments were similar between the 2 groups. Compared to hydroquinone, nightly treatment is not necessary with microneedling and TXA.²⁶

Xing et al²⁷ supported these conclusions with their study. They compared 3 study arms for a duration of 12 weeks: group A received topical 1.8% liposomal TXA BID, group B received stamp-mode electric microneedling with 5% TXA weekly, and group C applied 2% ­hydroquinone cream nightly. The study concluded that all 3 groups showed a significant reduction in mean MI by the end of the study, but a better MI improvement was observed in groups B and C (both P<.001) compared with group A (P<.01).²⁷

Zaky et al²⁸ showed that both hydroquinone and combination treatment of TXA plus microneedling are effective at improving melasma lesions. Further studies are needed to definitively conclude if combination treatment is more efficacious than hydroquinone; if the combination is more effective, it provides a treatment option for patients with melasma who may not be good candidates for hydroquinone treatment.

Study Limitations—One limitation in all the studies evaluated is the sample size. Because they all had small sample sizes, it is difficult to definitively conclude that the combination TXA and microneedling is an effective and appropriate treatment for patients with melasma. Furthermore, the quality of these studies was mostly dependent on subjectivity of the mMASI scores. Future large randomized controlled trials with a diverse participant population are needed to assess the effectiveness of TXA and microneedling in melasma treatment.

Another limitation is that many of the studies did not follow the patients longitudinally, which did not allow for an evaluation of whether patients had a relapse of melasma. Due to the chronic nature of melasma and frequent disease recurrence, future longitudinal studies are needed to monitor for disease recurrence.

Conclusion

Tranexamic acid and microneedling are potential treatment options for patients with melasma, and combination therapy appears more effective than either TXA or microneedling alone at providing sustained improvement of melasma lesions. Combination therapy appears safe and well tolerated, but its effect on reducing long-term disease recurrence is yet to be established.

Melasma (also known as chloasma faciei) is a common chronic skin disorder that results in well-demarcated, hyperpigmented, tan to dark patches that mostly appear in sun-exposed areas such as the face and neck and sometimes the arms. The exact prevalence or incidence is not known but is estimated to be 1% to 50% overall depending on the ethnic population and geographic location.^1,2 Melasma predominantly affects women, but research has shown that approximately 10% to 20% of men are affected by this condition.^3,4 Although melasma can affect patients of all skin types, it primarily affects those with darker skin tones.⁵ The groups most often affected are women of Black, Hispanic, Middle Eastern, and Southeast Asian ethnicity. Although the pathogenesis is complex and not fully understood, multiple pathways and etiologies have been theorized to cause melasma. Potential causes include exposure to UV radiation, oral contraceptives, hormonal changes, medications, thyroid dysfunction, genetics, and pregnancy.^6,7 Cytokines and growth factors, including adipokine and angiopoietin, synthesized by sebaceous glands play a role in the pathogenic mechanism of melasma. Cytokines and growth factors are hypothesized to modulate the function of melanocytes.⁸ Both melanocytes and sebocytes are controlled by α–melanocyte-stimulating hormone. Therefore, overexpression of α–melanocyte-stimulating hormone will result in overproduction of these 2 cell types, resulting in melasma. Melasma can be classified into 4 subtypes using Wood lamp examination: epidermal, dermal, mixed, or indeterminate.³ Furthermore, melasma is divided into subgroups based on the location: malar region, mandibular region, and centrofacial patch pattern.^9,10 The involvement of sebaceous glands in the pathogenesis of melasma may explain the predilection for the centrofacial region, which is the most common pattern.

The severity of melasma can be assessed using the melasma area and severity index (MASI), which is calculated by subjective assessment of 3 main factors: (1) facial area of involvement; (2) darkness of affected region; and (3) homogeneity, with the extent of melasma indicated by a score ranging from 0 to 48.¹¹ The modified MASI (mMASI) subsequently was introduced to assist with assessing the severity of melasma and creating distinct ranges for mild, moderate, and severe cases, ranging from 0 (mild) to 24 (severe).¹² Both indices are used in research to assess the improvement of melasma with treatment.

Patients with melasma report a decrease in quality of life, increased emotional stress, and lower self-esteem due to cosmesis.¹³ Treatment of melasma can be highly challenging and often is complicated by relapsing. Historically, the treatment of melasma has included the use of chemical lightening agents. Additional treatment options include the use of lasers and complex chemical peels,^9,10 but these interventions may result in adverse outcomes for individuals with darker skin tones. The current gold-standard treatment is topical hydroquinone and broad-spectrum sunscreen. Although hydroquinone is effective in the treatment of melasma, relapse is common. The goal of melasma management is not only to treat acute hyperpigmentation but also to prevent relapse. Other therapies that currently are being explored for the clinically sustained treatment of melasma include tranexamic acid (TXA)(trans-4-[aminomethyl]cyclohexanecarboxylic acid),^9,10 an antifibrinolytic agent routinely used to prevent blood loss during surgery and in the management of menorrhagia. It is a synthetic derivative of lysine and serves as a potent plasmin inhibitor by blocking the lysine-binding sites of plasminogen molecules, thus preventing the conversion of plasminogen to plasmin. It also prevents fibrinolysis and blood loss.

In addition to its hemostatic properties, TXA has been found to have hypopigmentation properties.^14,15 Plasminogen also can be found in human epidermal basal cells and human keratinocytes, and it is postulated that TXA’s interaction with these cells explains its hypopigmentation properties. Both UV radiation and hormones activate plasminogen into plasmin, resulting in the activation of tyrosinase and melanogenesis.^14,15 Tranexamic acid is postulated to inhibit the keratinocyte-plasminogen pathway, thus leading to the inhibition of UV-induced and hormone-induced pigmentation. Also, TXA serves as a competitive inhibitor for tyrosinase due to its structural similarity to tyrosine.¹⁵ The combination of these 2 mechanisms contributes to the skin-lightening effects of TXA, making it a potential treatment for melasma.

Furthermore, the use of microneedling is being explored as a treatment option for melasma. Microneedling creates microscopic punctures in the skin using tiny needles, resulting in a wound-healing response and skin resurfacing. The microneedling technique is utilized to create small holes in the skin, with needle depths that can be adjusted from 0.5 to 3.5 mm to target different layers of the dermis and allow for discreet application of TXA.¹⁶ We sought to look at the current literature on the use and effectiveness of microneedling in combination with TXA to treat melasma and prevent relapse.

Methods

A systematic review was performed of PubMed articles indexed for MEDLINE and Embase in November 2021 to compile available articles that studied TXA and microneedling as a treatment for melasma. The PubMed search terms were (melasma) AND (microneedling* OR ‘tranexamic acid’ OR TXA or TA). The Embase search terms were (cholasma OR melasma) AND (tranexamic acid OR TXA) AND (microneedling)(Figure). The search was then limited to ”randomized controlled trial” and ”clinical trial” in English-language journals. Duplicates were excluded. After thorough evaluation, articles that discussed the use of TXA in combination with treatment options other than microneedling also were excluded.

Results

The literature search yielded a total of 12 articles that assessed the effectiveness of TXA and microneedling for the treatment of melasma (Table).^17-28 Several articles concluded that TXA was equally effective at reducing melasma lesions when compared with the standard treatment of hydroquinone. Some of the reviewed articles also demonstrated the effectiveness of microneedling in improving melasma lesions as a stand-alone treatment. These studies highlighted the enhanced efficacy of the combined treatment of TXA and microneedling compared with their individual uses.^17-28

Comment

Melasma is a common chronic hyperpigmentation disorder, making its treatment clinically challenging. Many patients experience symptom relapses, and limited effective treatment options make achieving complete clearance difficult, underscoring the need for improved therapeutic approaches. Recently, researchers have explored alternative treatments to address the challenges of melasma management. Tranexamic acid is an antifibrinolytic used to prevent blood loss and has emerged as a potential treatment for melasma. Similarly, microneedling—a technique in which multiple punctures are made in the skin to activate and stimulate wound healing and skin rejuvenation—shows promise for melasma.

Oral TXA for Melasma—Oral TXA has been shown to reduce melasma lesions. Del Rosario et al¹⁷ recruited 44 women (39 of whom completed the study) with moderate to severe melasma and randomized them into 2 groups: oral TXA and placebo. This study demonstrated a 49% reduction in the mMASI score in all participants taking oral TXA (250 mg twice daily [BID]) compared with an 18% reduction in the control group (placebo capsule BID) after 3 months of treatment. In patients with moderate and severe melasma, 45% and 51% mMASI score reductions were reported in the treatment group, respectively, vs 16% and 19% score reductions in placebo group, respectively. These researchers concluded that oral TXA may be effective at treating moderate to severe melasma. Although patients with severe melasma had a better response to treatment, their improvement was not sustained compared with patients with moderate melasma after a 3-month posttreatment follow-up.¹⁷

Microneedling Plus TXA for Melasma—Microneedling alone has been shown to be effective for melasma. El Attar et al¹⁸ conducted a split-face study of microneedling (1.5-mm depth) plus topical TXA (0.5 mL)(right side of the face[treatment arm]) compared with microneedling (1.5-mm depth) plus topical vitamin C (0.5 mL)(left side of the face [control group]) in 20 women with melasma. The sessions were repeated every 2 weeks for a total of 6 sessions. Although researchers found no statistically significant differences between the 2 treatment sides, microneedling plus TXA showed a slight advantage over microneedling plus vitamin C in dermoscopic examination. Both sides showed improvement in pigmented lesions, but vitamin C–treated lesions did not show an improvement in vascularity vs TXA.¹⁸

Saleh et al¹⁹ further showed that combination treatment with microneedling and TXA may improve clinical outcomes better than microneedling alone. Their study demonstrated a reduction in MASI score that was significantly higher in the combination treatment group compared with the microneedling alone group (P=.001). There was a significant reduction in melanoma antigen recognized by T cells 1 (MART-1)–positive cells in the combination treatment group compared with the microneedling alone group (P=.001). Lastly, combined therapy improved melasma patches better than microneedling alone.¹⁹

Xu et al²⁰ conducted a split-face study (N=28) exploring the effectiveness of transdermal application of topical TXA using a microarray pen with microneedles (vibration at 3000×/min) plus topical TXA on one side of the face, while the other side received only topical TXA as a control. After 12 weeks of treatment, combination therapy with microneedling and TXA decreased brown spot scores, lowered melanin index (MI) values, improved blinded physician assessment, and improved patient satisfaction vs TXA therapy alone.²⁰

Kaur et al²¹ conducted a split-face, randomized, controlled trial of microneedling (1-mm depth) with TXA solution 10% vs microneedling (1-mm depth) with distilled water alone for 8 weeks (N=40). They graded participant responses to treatment using reductions in mMASI scores¹² at every 2 weeks of follow-up (no response, minimal or poor response=0%–25%; partial or fair response=26%–50%; good response=51%–75%; and excellent response=>75%). They reported an overall reduction in mMASI scores for both the treatment side and the control side in all participants, showing a 65.92% improvement in mean mMASI scores on the treatment side vs 20.75% improvement on the control side at week 8. Both sides showed statistically significant reductions in mean mMASI scores (P<.05). Clinically, 40% (16/40) of participants showed an excellent response to combined treatment compared with 0% (0/40) to microneedling alone. Overall, patient satisfaction was similar across both groups. This study demonstrated that microneedling alone improves melasma, but a combination of microneedling plus TXA showed a better clinical reduction in melasma. However, the researchers did not follow up with participants posttreatment, so it remains unclear if the improved clinical outcomes were sustained long-term.²¹

Ebrahim et al²² reported that the combination of 0.5 mL TXA (4 mg/mL) and microneedling (0.25- to 1-mm depth) was effective for melasma. Although there was improvement within microneedling and TXA, the study also showed that intradermal injection of TXA was significant in reducing mean mMASI scores and improving melasma (P<.001). The reduction in mMASI scores for the group receiving intradermal injections of TXA (left side; 74.8% reduction in mean mMASI score) vs the group receiving microneedling application of TXA (right side; 73.6% reduction in mean mMASI score) was not statistically significant. These findings suggest that the mode of TXA application may not be critical in determining clinical responses to TXA treatment. Although there was no reported statistically significant difference in clinical outcomes between the 2 treatments, patient satisfaction was higher on the microneedling side. Only 8 of 50 participants (16%) experienced recurrence 3 months posttreatment.²²

Saki et al²³ compared the efficacy of topical hydroquinone (2%) to intradermal TXA injections in treating melasma. They found intradermal TXA injections to be a clinically effective mode of treatment.²³

Sharma et al²⁴ explored the efficacy and safety of oral TXA by randomly assigning 100 Indian patients (20 of whom withdrew before study completion) with melasma into 2 groups: group A received TXA 250 mg twice daily, and group B received intradermal microinjections of TXA (4 mg/mL) every 4 weeks. The MASI scores were assessed at 4-week intervals for a total of 12 weeks. There was a decrease in MASI scores in both groups, and there was no statistically significant difference in mean percentage reduction in MASI scores between the 2 routes of drug administration, further suggesting the effectiveness of TXA independent of administration route. Two patients in group A relapsed at 24 weeks, and there were no relapses in group B, which may suggest a minimal superiority of TXA plus microneedling at providing more sustainable results compared with oral TXA alone. A notable limitation of this study was a high dropout rate as well as lack of long-term follow-up with participants, limiting the generalizability of the conclusions.²⁴

Cassiano et al²⁵ assigned 64 women with melasma to 1 of 3 treatment groups or a control group to compare the effectiveness of microneedling (M group: 1.5 mm; 2 sessions), oral TXA (T group: 250 mg/d twice daily for 60 days), and a combination of microneedling (2 sessions) and oral TXA (MT group: 250 mg/d twice daily for 60 days)with placebo for clinically reducing melasma lesions. The intervention period was 60 days followed by a 60-day maintenance phase for a total study period of 120 days. The researchers evaluated mMASI scores, quality of life, and difference in colorimetric luminosity. All treatment groups showed a reduction in mMASI scores at both 30 days and 60 days, indicating improved melasma severity. The MT and T groups had more significant improvement at 30 days compared with the control group (P<.03), suggesting that microneedling plus TXA and TXA alone promote faster improvement in melasma lesions. By 60 days, the M, T, and MT groups outperformed the control group, with no significant differences between the M, T, and MT groups. However, at the 120-day maintenance follow-up, the T group did not maintain its improvement compared with the control group. The M and MT groups showed no significance difference in effectiveness at 120 days, suggesting that microneedling may promote less frequent relapse and sustained remission compared to TXA alone.²⁵

Hydroquinone for Melasma—Additional studies on the use of TXA treatments show that TXA may be an equally effective alternative to the standard use of hydroquinone treatment. Shamsi Meymandi et al²⁶ did not find a statistically significant difference in treatment with TXA plus microneedling vs the standard regimen of hydroquinone. More importantly, patient and physician satisfaction assessments were similar between the 2 groups. Compared to hydroquinone, nightly treatment is not necessary with microneedling and TXA.²⁶

Xing et al²⁷ supported these conclusions with their study. They compared 3 study arms for a duration of 12 weeks: group A received topical 1.8% liposomal TXA BID, group B received stamp-mode electric microneedling with 5% TXA weekly, and group C applied 2% ­hydroquinone cream nightly. The study concluded that all 3 groups showed a significant reduction in mean MI by the end of the study, but a better MI improvement was observed in groups B and C (both P<.001) compared with group A (P<.01).²⁷

Zaky et al²⁸ showed that both hydroquinone and combination treatment of TXA plus microneedling are effective at improving melasma lesions. Further studies are needed to definitively conclude if combination treatment is more efficacious than hydroquinone; if the combination is more effective, it provides a treatment option for patients with melasma who may not be good candidates for hydroquinone treatment.

Study Limitations—One limitation in all the studies evaluated is the sample size. Because they all had small sample sizes, it is difficult to definitively conclude that the combination TXA and microneedling is an effective and appropriate treatment for patients with melasma. Furthermore, the quality of these studies was mostly dependent on subjectivity of the mMASI scores. Future large randomized controlled trials with a diverse participant population are needed to assess the effectiveness of TXA and microneedling in melasma treatment.

Another limitation is that many of the studies did not follow the patients longitudinally, which did not allow for an evaluation of whether patients had a relapse of melasma. Due to the chronic nature of melasma and frequent disease recurrence, future longitudinal studies are needed to monitor for disease recurrence.

Conclusion

Tranexamic acid and microneedling are potential treatment options for patients with melasma, and combination therapy appears more effective than either TXA or microneedling alone at providing sustained improvement of melasma lesions. Combination therapy appears safe and well tolerated, but its effect on reducing long-term disease recurrence is yet to be established.

Melasma (also known as chloasma faciei) is a common chronic skin disorder that results in well-demarcated, hyperpigmented, tan to dark patches that mostly appear in sun-exposed areas such as the face and neck and sometimes the arms. The exact prevalence or incidence is not known but is estimated to be 1% to 50% overall depending on the ethnic population and geographic location.^1,2 Melasma predominantly affects women, but research has shown that approximately 10% to 20% of men are affected by this condition.^3,4 Although melasma can affect patients of all skin types, it primarily affects those with darker skin tones.⁵ The groups most often affected are women of Black, Hispanic, Middle Eastern, and Southeast Asian ethnicity. Although the pathogenesis is complex and not fully understood, multiple pathways and etiologies have been theorized to cause melasma. Potential causes include exposure to UV radiation, oral contraceptives, hormonal changes, medications, thyroid dysfunction, genetics, and pregnancy.^6,7 Cytokines and growth factors, including adipokine and angiopoietin, synthesized by sebaceous glands play a role in the pathogenic mechanism of melasma. Cytokines and growth factors are hypothesized to modulate the function of melanocytes.⁸ Both melanocytes and sebocytes are controlled by α–melanocyte-stimulating hormone. Therefore, overexpression of α–melanocyte-stimulating hormone will result in overproduction of these 2 cell types, resulting in melasma. Melasma can be classified into 4 subtypes using Wood lamp examination: epidermal, dermal, mixed, or indeterminate.³ Furthermore, melasma is divided into subgroups based on the location: malar region, mandibular region, and centrofacial patch pattern.^9,10 The involvement of sebaceous glands in the pathogenesis of melasma may explain the predilection for the centrofacial region, which is the most common pattern.

The severity of melasma can be assessed using the melasma area and severity index (MASI), which is calculated by subjective assessment of 3 main factors: (1) facial area of involvement; (2) darkness of affected region; and (3) homogeneity, with the extent of melasma indicated by a score ranging from 0 to 48.¹¹ The modified MASI (mMASI) subsequently was introduced to assist with assessing the severity of melasma and creating distinct ranges for mild, moderate, and severe cases, ranging from 0 (mild) to 24 (severe).¹² Both indices are used in research to assess the improvement of melasma with treatment.

Patients with melasma report a decrease in quality of life, increased emotional stress, and lower self-esteem due to cosmesis.¹³ Treatment of melasma can be highly challenging and often is complicated by relapsing. Historically, the treatment of melasma has included the use of chemical lightening agents. Additional treatment options include the use of lasers and complex chemical peels,^9,10 but these interventions may result in adverse outcomes for individuals with darker skin tones. The current gold-standard treatment is topical hydroquinone and broad-spectrum sunscreen. Although hydroquinone is effective in the treatment of melasma, relapse is common. The goal of melasma management is not only to treat acute hyperpigmentation but also to prevent relapse. Other therapies that currently are being explored for the clinically sustained treatment of melasma include tranexamic acid (TXA)(trans-4-[aminomethyl]cyclohexanecarboxylic acid),^9,10 an antifibrinolytic agent routinely used to prevent blood loss during surgery and in the management of menorrhagia. It is a synthetic derivative of lysine and serves as a potent plasmin inhibitor by blocking the lysine-binding sites of plasminogen molecules, thus preventing the conversion of plasminogen to plasmin. It also prevents fibrinolysis and blood loss.

In addition to its hemostatic properties, TXA has been found to have hypopigmentation properties.^14,15 Plasminogen also can be found in human epidermal basal cells and human keratinocytes, and it is postulated that TXA’s interaction with these cells explains its hypopigmentation properties. Both UV radiation and hormones activate plasminogen into plasmin, resulting in the activation of tyrosinase and melanogenesis.^14,15 Tranexamic acid is postulated to inhibit the keratinocyte-plasminogen pathway, thus leading to the inhibition of UV-induced and hormone-induced pigmentation. Also, TXA serves as a competitive inhibitor for tyrosinase due to its structural similarity to tyrosine.¹⁵ The combination of these 2 mechanisms contributes to the skin-lightening effects of TXA, making it a potential treatment for melasma.

Furthermore, the use of microneedling is being explored as a treatment option for melasma. Microneedling creates microscopic punctures in the skin using tiny needles, resulting in a wound-healing response and skin resurfacing. The microneedling technique is utilized to create small holes in the skin, with needle depths that can be adjusted from 0.5 to 3.5 mm to target different layers of the dermis and allow for discreet application of TXA.¹⁶ We sought to look at the current literature on the use and effectiveness of microneedling in combination with TXA to treat melasma and prevent relapse.

Methods

A systematic review was performed of PubMed articles indexed for MEDLINE and Embase in November 2021 to compile available articles that studied TXA and microneedling as a treatment for melasma. The PubMed search terms were (melasma) AND (microneedling* OR ‘tranexamic acid’ OR TXA or TA). The Embase search terms were (cholasma OR melasma) AND (tranexamic acid OR TXA) AND (microneedling)(Figure). The search was then limited to ”randomized controlled trial” and ”clinical trial” in English-language journals. Duplicates were excluded. After thorough evaluation, articles that discussed the use of TXA in combination with treatment options other than microneedling also were excluded.

Results

The literature search yielded a total of 12 articles that assessed the effectiveness of TXA and microneedling for the treatment of melasma (Table).^17-28 Several articles concluded that TXA was equally effective at reducing melasma lesions when compared with the standard treatment of hydroquinone. Some of the reviewed articles also demonstrated the effectiveness of microneedling in improving melasma lesions as a stand-alone treatment. These studies highlighted the enhanced efficacy of the combined treatment of TXA and microneedling compared with their individual uses.^17-28

Comment

Melasma is a common chronic hyperpigmentation disorder, making its treatment clinically challenging. Many patients experience symptom relapses, and limited effective treatment options make achieving complete clearance difficult, underscoring the need for improved therapeutic approaches. Recently, researchers have explored alternative treatments to address the challenges of melasma management. Tranexamic acid is an antifibrinolytic used to prevent blood loss and has emerged as a potential treatment for melasma. Similarly, microneedling—a technique in which multiple punctures are made in the skin to activate and stimulate wound healing and skin rejuvenation—shows promise for melasma.

Oral TXA for Melasma—Oral TXA has been shown to reduce melasma lesions. Del Rosario et al¹⁷ recruited 44 women (39 of whom completed the study) with moderate to severe melasma and randomized them into 2 groups: oral TXA and placebo. This study demonstrated a 49% reduction in the mMASI score in all participants taking oral TXA (250 mg twice daily [BID]) compared with an 18% reduction in the control group (placebo capsule BID) after 3 months of treatment. In patients with moderate and severe melasma, 45% and 51% mMASI score reductions were reported in the treatment group, respectively, vs 16% and 19% score reductions in placebo group, respectively. These researchers concluded that oral TXA may be effective at treating moderate to severe melasma. Although patients with severe melasma had a better response to treatment, their improvement was not sustained compared with patients with moderate melasma after a 3-month posttreatment follow-up.¹⁷

Microneedling Plus TXA for Melasma—Microneedling alone has been shown to be effective for melasma. El Attar et al¹⁸ conducted a split-face study of microneedling (1.5-mm depth) plus topical TXA (0.5 mL)(right side of the face[treatment arm]) compared with microneedling (1.5-mm depth) plus topical vitamin C (0.5 mL)(left side of the face [control group]) in 20 women with melasma. The sessions were repeated every 2 weeks for a total of 6 sessions. Although researchers found no statistically significant differences between the 2 treatment sides, microneedling plus TXA showed a slight advantage over microneedling plus vitamin C in dermoscopic examination. Both sides showed improvement in pigmented lesions, but vitamin C–treated lesions did not show an improvement in vascularity vs TXA.¹⁸

Saleh et al¹⁹ further showed that combination treatment with microneedling and TXA may improve clinical outcomes better than microneedling alone. Their study demonstrated a reduction in MASI score that was significantly higher in the combination treatment group compared with the microneedling alone group (P=.001). There was a significant reduction in melanoma antigen recognized by T cells 1 (MART-1)–positive cells in the combination treatment group compared with the microneedling alone group (P=.001). Lastly, combined therapy improved melasma patches better than microneedling alone.¹⁹

Xu et al²⁰ conducted a split-face study (N=28) exploring the effectiveness of transdermal application of topical TXA using a microarray pen with microneedles (vibration at 3000×/min) plus topical TXA on one side of the face, while the other side received only topical TXA as a control. After 12 weeks of treatment, combination therapy with microneedling and TXA decreased brown spot scores, lowered melanin index (MI) values, improved blinded physician assessment, and improved patient satisfaction vs TXA therapy alone.²⁰

Kaur et al²¹ conducted a split-face, randomized, controlled trial of microneedling (1-mm depth) with TXA solution 10% vs microneedling (1-mm depth) with distilled water alone for 8 weeks (N=40). They graded participant responses to treatment using reductions in mMASI scores¹² at every 2 weeks of follow-up (no response, minimal or poor response=0%–25%; partial or fair response=26%–50%; good response=51%–75%; and excellent response=>75%). They reported an overall reduction in mMASI scores for both the treatment side and the control side in all participants, showing a 65.92% improvement in mean mMASI scores on the treatment side vs 20.75% improvement on the control side at week 8. Both sides showed statistically significant reductions in mean mMASI scores (P<.05). Clinically, 40% (16/40) of participants showed an excellent response to combined treatment compared with 0% (0/40) to microneedling alone. Overall, patient satisfaction was similar across both groups. This study demonstrated that microneedling alone improves melasma, but a combination of microneedling plus TXA showed a better clinical reduction in melasma. However, the researchers did not follow up with participants posttreatment, so it remains unclear if the improved clinical outcomes were sustained long-term.²¹

Ebrahim et al²² reported that the combination of 0.5 mL TXA (4 mg/mL) and microneedling (0.25- to 1-mm depth) was effective for melasma. Although there was improvement within microneedling and TXA, the study also showed that intradermal injection of TXA was significant in reducing mean mMASI scores and improving melasma (P<.001). The reduction in mMASI scores for the group receiving intradermal injections of TXA (left side; 74.8% reduction in mean mMASI score) vs the group receiving microneedling application of TXA (right side; 73.6% reduction in mean mMASI score) was not statistically significant. These findings suggest that the mode of TXA application may not be critical in determining clinical responses to TXA treatment. Although there was no reported statistically significant difference in clinical outcomes between the 2 treatments, patient satisfaction was higher on the microneedling side. Only 8 of 50 participants (16%) experienced recurrence 3 months posttreatment.²²

Saki et al²³ compared the efficacy of topical hydroquinone (2%) to intradermal TXA injections in treating melasma. They found intradermal TXA injections to be a clinically effective mode of treatment.²³

Sharma et al²⁴ explored the efficacy and safety of oral TXA by randomly assigning 100 Indian patients (20 of whom withdrew before study completion) with melasma into 2 groups: group A received TXA 250 mg twice daily, and group B received intradermal microinjections of TXA (4 mg/mL) every 4 weeks. The MASI scores were assessed at 4-week intervals for a total of 12 weeks. There was a decrease in MASI scores in both groups, and there was no statistically significant difference in mean percentage reduction in MASI scores between the 2 routes of drug administration, further suggesting the effectiveness of TXA independent of administration route. Two patients in group A relapsed at 24 weeks, and there were no relapses in group B, which may suggest a minimal superiority of TXA plus microneedling at providing more sustainable results compared with oral TXA alone. A notable limitation of this study was a high dropout rate as well as lack of long-term follow-up with participants, limiting the generalizability of the conclusions.²⁴

Cassiano et al²⁵ assigned 64 women with melasma to 1 of 3 treatment groups or a control group to compare the effectiveness of microneedling (M group: 1.5 mm; 2 sessions), oral TXA (T group: 250 mg/d twice daily for 60 days), and a combination of microneedling (2 sessions) and oral TXA (MT group: 250 mg/d twice daily for 60 days)with placebo for clinically reducing melasma lesions. The intervention period was 60 days followed by a 60-day maintenance phase for a total study period of 120 days. The researchers evaluated mMASI scores, quality of life, and difference in colorimetric luminosity. All treatment groups showed a reduction in mMASI scores at both 30 days and 60 days, indicating improved melasma severity. The MT and T groups had more significant improvement at 30 days compared with the control group (P<.03), suggesting that microneedling plus TXA and TXA alone promote faster improvement in melasma lesions. By 60 days, the M, T, and MT groups outperformed the control group, with no significant differences between the M, T, and MT groups. However, at the 120-day maintenance follow-up, the T group did not maintain its improvement compared with the control group. The M and MT groups showed no significance difference in effectiveness at 120 days, suggesting that microneedling may promote less frequent relapse and sustained remission compared to TXA alone.²⁵

Hydroquinone for Melasma—Additional studies on the use of TXA treatments show that TXA may be an equally effective alternative to the standard use of hydroquinone treatment. Shamsi Meymandi et al²⁶ did not find a statistically significant difference in treatment with TXA plus microneedling vs the standard regimen of hydroquinone. More importantly, patient and physician satisfaction assessments were similar between the 2 groups. Compared to hydroquinone, nightly treatment is not necessary with microneedling and TXA.²⁶

Xing et al²⁷ supported these conclusions with their study. They compared 3 study arms for a duration of 12 weeks: group A received topical 1.8% liposomal TXA BID, group B received stamp-mode electric microneedling with 5% TXA weekly, and group C applied 2% ­hydroquinone cream nightly. The study concluded that all 3 groups showed a significant reduction in mean MI by the end of the study, but a better MI improvement was observed in groups B and C (both P<.001) compared with group A (P<.01).²⁷

Zaky et al²⁸ showed that both hydroquinone and combination treatment of TXA plus microneedling are effective at improving melasma lesions. Further studies are needed to definitively conclude if combination treatment is more efficacious than hydroquinone; if the combination is more effective, it provides a treatment option for patients with melasma who may not be good candidates for hydroquinone treatment.

Study Limitations—One limitation in all the studies evaluated is the sample size. Because they all had small sample sizes, it is difficult to definitively conclude that the combination TXA and microneedling is an effective and appropriate treatment for patients with melasma. Furthermore, the quality of these studies was mostly dependent on subjectivity of the mMASI scores. Future large randomized controlled trials with a diverse participant population are needed to assess the effectiveness of TXA and microneedling in melasma treatment.

Another limitation is that many of the studies did not follow the patients longitudinally, which did not allow for an evaluation of whether patients had a relapse of melasma. Due to the chronic nature of melasma and frequent disease recurrence, future longitudinal studies are needed to monitor for disease recurrence.

Conclusion

Tranexamic acid and microneedling are potential treatment options for patients with melasma, and combination therapy appears more effective than either TXA or microneedling alone at providing sustained improvement of melasma lesions. Combination therapy appears safe and well tolerated, but its effect on reducing long-term disease recurrence is yet to be established.

The Diagnosis: Brunsting-Perry Cicatricial Pemphigoid

Physical examination and histopathology are paramount in diagnosing Brunsting-Perry cicatricial pemphigoid (BPCP). In our patient, histopathology showed subepidermal blistering with a mixed superficial dermal inflammatory cell infiltrate. Direct immunofluorescence was positive for linear IgG and C3 antibodies along the basement membrane. The scarring erosions on the scalp combined with the autoantibody findings on direct immunofluorescence were consistent with BPCP. He was started on dapsone 100 mg daily and demonstrated complete resolution of symptoms after 10 months, with the exception of persistent scarring hair loss (Figure).

Brunsting-Perry cicatricial pemphigoid is a rare dermatologic condition. It was first defined in 1957 when Brunsting and Perry¹ examined 7 patients with cicatricial pemphigoid that predominantly affected the head and neck region, with occasional mucous membrane involvement but no mucosal scarring. Characteristically, BPCP manifests as scarring herpetiform plaques with varied blisters, erosions, crusts, and scarring.¹ It primarily affects middle-aged men.²

Historically, BPCP has been considered a variant of cicatricial pemphigoid (now known as mucous membrane pemphigoid), bullous pemphigoid, or epidermolysis bullosa acquisita.³ The antigen target has not been established clearly; however, autoantibodies against laminin 332, collagen VII, and BP180 and BP230 have been proposed.^2,4,5 Jacoby et al6 described BPCP on a spectrum with bullous pemphigoid and cicatricial pemphigoid, with primarily circulating autoantibodies on one end and tissue-fixed autoantibodies on the other.

The differential for BPCP also includes anti-p200 pemphigoid and anti–laminin 332 pemphigoid. Anti-p200 pemphigoid also is known as bullous pemphigoid with antibodies against the 200-kDa protein.⁷ It may clinically manifest similar to bullous pemphigoid and other subepidermal autoimmune blistering diseases; thus, immunopathologic differentiation can be helpful. Anti–laminin 332 pemphigoid (also known as anti–laminin gamma-1 pemphigoid) is characterized by autoantibodies targeting the laminin 332 protein in the basement membrane zone, resulting in blistering and erosions.⁸ Similar to BPCP and epidermolysis bullosa aquisita, anti–laminin 332 pemphigoid may affect cephalic regions and mucous membrane surfaces, resulting in scarring and cicatricial changes. Anti–laminin 332 pemphigoid also has been associated with internal malignancy.⁸ The use of the salt-split skin technique can be utilized to differentiate these entities based on their autoantibody-binding patterns in relation to the lamina densa.

Treatment options for mild BPCP include potent topical or intralesional steroids and dapsone, while more severe cases may require systemic therapy with rituximab, azathioprine, mycophenolate mofetil, or cyclophosphamide.⁴

This case highlights the importance of histopathologic examination of skin lesions with an unusual history or clinical presentation. Dermatologists should consider BPCP when presented with erosions, ulcerations, or blisters of the head and neck in middle-aged male patients.

The Diagnosis: Brunsting-Perry Cicatricial Pemphigoid

Physical examination and histopathology are paramount in diagnosing Brunsting-Perry cicatricial pemphigoid (BPCP). In our patient, histopathology showed subepidermal blistering with a mixed superficial dermal inflammatory cell infiltrate. Direct immunofluorescence was positive for linear IgG and C3 antibodies along the basement membrane. The scarring erosions on the scalp combined with the autoantibody findings on direct immunofluorescence were consistent with BPCP. He was started on dapsone 100 mg daily and demonstrated complete resolution of symptoms after 10 months, with the exception of persistent scarring hair loss (Figure).

Brunsting-Perry cicatricial pemphigoid is a rare dermatologic condition. It was first defined in 1957 when Brunsting and Perry¹ examined 7 patients with cicatricial pemphigoid that predominantly affected the head and neck region, with occasional mucous membrane involvement but no mucosal scarring. Characteristically, BPCP manifests as scarring herpetiform plaques with varied blisters, erosions, crusts, and scarring.¹ It primarily affects middle-aged men.²

Historically, BPCP has been considered a variant of cicatricial pemphigoid (now known as mucous membrane pemphigoid), bullous pemphigoid, or epidermolysis bullosa acquisita.³ The antigen target has not been established clearly; however, autoantibodies against laminin 332, collagen VII, and BP180 and BP230 have been proposed.^2,4,5 Jacoby et al6 described BPCP on a spectrum with bullous pemphigoid and cicatricial pemphigoid, with primarily circulating autoantibodies on one end and tissue-fixed autoantibodies on the other.

The differential for BPCP also includes anti-p200 pemphigoid and anti–laminin 332 pemphigoid. Anti-p200 pemphigoid also is known as bullous pemphigoid with antibodies against the 200-kDa protein.⁷ It may clinically manifest similar to bullous pemphigoid and other subepidermal autoimmune blistering diseases; thus, immunopathologic differentiation can be helpful. Anti–laminin 332 pemphigoid (also known as anti–laminin gamma-1 pemphigoid) is characterized by autoantibodies targeting the laminin 332 protein in the basement membrane zone, resulting in blistering and erosions.⁸ Similar to BPCP and epidermolysis bullosa aquisita, anti–laminin 332 pemphigoid may affect cephalic regions and mucous membrane surfaces, resulting in scarring and cicatricial changes. Anti–laminin 332 pemphigoid also has been associated with internal malignancy.⁸ The use of the salt-split skin technique can be utilized to differentiate these entities based on their autoantibody-binding patterns in relation to the lamina densa.

Treatment options for mild BPCP include potent topical or intralesional steroids and dapsone, while more severe cases may require systemic therapy with rituximab, azathioprine, mycophenolate mofetil, or cyclophosphamide.⁴

This case highlights the importance of histopathologic examination of skin lesions with an unusual history or clinical presentation. Dermatologists should consider BPCP when presented with erosions, ulcerations, or blisters of the head and neck in middle-aged male patients.

The Diagnosis: Brunsting-Perry Cicatricial Pemphigoid

Physical examination and histopathology are paramount in diagnosing Brunsting-Perry cicatricial pemphigoid (BPCP). In our patient, histopathology showed subepidermal blistering with a mixed superficial dermal inflammatory cell infiltrate. Direct immunofluorescence was positive for linear IgG and C3 antibodies along the basement membrane. The scarring erosions on the scalp combined with the autoantibody findings on direct immunofluorescence were consistent with BPCP. He was started on dapsone 100 mg daily and demonstrated complete resolution of symptoms after 10 months, with the exception of persistent scarring hair loss (Figure).

Brunsting-Perry cicatricial pemphigoid is a rare dermatologic condition. It was first defined in 1957 when Brunsting and Perry¹ examined 7 patients with cicatricial pemphigoid that predominantly affected the head and neck region, with occasional mucous membrane involvement but no mucosal scarring. Characteristically, BPCP manifests as scarring herpetiform plaques with varied blisters, erosions, crusts, and scarring.¹ It primarily affects middle-aged men.²

Historically, BPCP has been considered a variant of cicatricial pemphigoid (now known as mucous membrane pemphigoid), bullous pemphigoid, or epidermolysis bullosa acquisita.³ The antigen target has not been established clearly; however, autoantibodies against laminin 332, collagen VII, and BP180 and BP230 have been proposed.^2,4,5 Jacoby et al6 described BPCP on a spectrum with bullous pemphigoid and cicatricial pemphigoid, with primarily circulating autoantibodies on one end and tissue-fixed autoantibodies on the other.

The differential for BPCP also includes anti-p200 pemphigoid and anti–laminin 332 pemphigoid. Anti-p200 pemphigoid also is known as bullous pemphigoid with antibodies against the 200-kDa protein.⁷ It may clinically manifest similar to bullous pemphigoid and other subepidermal autoimmune blistering diseases; thus, immunopathologic differentiation can be helpful. Anti–laminin 332 pemphigoid (also known as anti–laminin gamma-1 pemphigoid) is characterized by autoantibodies targeting the laminin 332 protein in the basement membrane zone, resulting in blistering and erosions.⁸ Similar to BPCP and epidermolysis bullosa aquisita, anti–laminin 332 pemphigoid may affect cephalic regions and mucous membrane surfaces, resulting in scarring and cicatricial changes. Anti–laminin 332 pemphigoid also has been associated with internal malignancy.⁸ The use of the salt-split skin technique can be utilized to differentiate these entities based on their autoantibody-binding patterns in relation to the lamina densa.

Treatment options for mild BPCP include potent topical or intralesional steroids and dapsone, while more severe cases may require systemic therapy with rituximab, azathioprine, mycophenolate mofetil, or cyclophosphamide.⁴

This case highlights the importance of histopathologic examination of skin lesions with an unusual history or clinical presentation. Dermatologists should consider BPCP when presented with erosions, ulcerations, or blisters of the head and neck in middle-aged male patients.

Pruritus, which is defined as an itching sensation that elicits a desire to scratch, is the most common cutaneous condition. Pruritus is considered chronic when it lasts for more than 6 weeks.¹ Etiologies implicated in chronic pruritus include but are not limited to primary skin diseases such as atopic dermatitis, systemic causes, neuropathic disorders, and psychogenic reasons.² In approximately 8% to 35% of patients, the cause of pruritus remains elusive despite intensive investigation.³ The mechanisms of itch are multifaceted and include complex neural pathways.⁴ Although itch and pain share many similarities, they have distinct pathways based on their spinal connections.⁵ Nevertheless, both conditions show a wide overlap of receptors on peripheral nerve endings and activated brain parts.^6,7 Fibromyalgia, the third most common musculoskeletal condition, affects 2% to 3% of the population worldwide and is at least 7 times more common in females.^8,9 Its pathogenesis is not entirely clear but is thought to involve neurogenic inflammation, aberrations in peripheral nerves, and central pain mechanisms. Fibromyalgia is characterized by a plethora of symptoms including chronic widespread pain, autonomic disturbances, persistent fatigue and sleep disturbances, and hyperalgesia, as well as somatic and psychiatric symptoms.¹⁰

Fibromyalgia is accompanied by altered skin features including increased counts of mast cells and excessive degranulation,¹¹ neurogenic inflammation with elevated cytokine expression,¹² disrupted collagen metabolism,¹³ and microcirculation abnormalities.¹⁴ There has been limited research exploring the dermatologic manifestations of fibromyalgia. One retrospective study that included 845 patients with fibromyalgia reported increased occurrence of “neurodermatoses,” including pruritus, neurotic excoriations, prurigo nodules, and lichen simplex chronicus (LSC), among other cutaneous comorbidities.¹⁵ Another small study demonstrated an increased incidence of xerosis and neurotic excoriations in females with fibromyalgia.¹⁶ A paucity of large epidemiologic studies demonstrating the fibromyalgia-pruritus connection may lead to misdiagnosis, misinterpretation, and undertreatment of these patients.

Up to 49% of fibromyalgia patients experience small-fiber neuropathy.¹⁷ Electrophysiologic measurements, quantitative sensory testing, pain-related evoked potentials, and skin biopsies showed that patients with fibromyalgia have compromised small-fiber function, impaired pathways carrying fiber pain signals, and reduced skin innervation and regenerating fibers.^18,19 Accordingly, pruritus that has been reported in fibromyalgia is believed to be of neuropathic origin.¹⁵ Overall, it is suspected that the same mechanism that causes hypersensitivity and pain in fibromyalgia patients also predisposes them to pruritus. Similar systemic treatments (eg, analgesics, antidepressants, anticonvulsants) prescribed for both conditions support this theory.^20-25

Our large cross-sectional study sought to establish the association between fibromyalgia and pruritus as well as related pruritic conditions.

Methods

Study Design and Setting—We conducted a cross-­sectional retrospective study using data-mining techniques to access information from the Clalit Health Services (CHS) database. Clalit Health Services is the largest health maintenance organization in Israel. It encompasses an extensive database with continuous real-time input from medical, administrative, and pharmaceutical computerized operating systems, which helps facilitate data collection for epidemiologic studies. A chronic disease register is gathered from these data sources and continuously updated and validated through logistic checks. The current study was approved by the institutional review board of the CHS (approval #0212-17-com2). Informed consent was not required because the data were de-identified and this was a noninterventional observational study.

Study Population and Covariates—Medical records of CHS enrollees were screened for the diagnosis of fibromyalgia, and data on prevalent cases of fibromyalgia were retrieved. The diagnosis of fibromyalgia was based on the documentation of a fibromyalgia-specific diagnostic code registered by a board-certified rheumatologist. A control group of individuals without fibromyalgia was selected through 1:2 matching based on age, sex, and primary care clinic. The control group was randomly selected from the list of CHS members frequency-matched to cases, excluding case patients with fibromyalgia. Age matching was grounded on the exact year of birth (1-year strata).

Other covariates in the analysis included pruritus-related skin disorders, including prurigo nodularis, neurotic excoriations, and LSC. There were 3 socioeconomic status categories according to patients' poverty index: low, intermediate, and high.²⁶

Statistical Analysis—The distribution of sociodemographic and clinical features was compared between patients with fibromyalgia and controls using the χ² test for sex and socioeconomic status and the t test for age. Conditional logistic regression then was used to calculate adjusted odds ratio (OR) and 95% CI to compare patients with fibromyalgia and controls with respect to the presence of pruritic comorbidities. All statistical analyses were performed using SPSS software (version 26). P<.05 was considered statistically significant in all tests.

Results

Our study population comprised 4971 patients with fibromyalgia and 9896 age- and sex-matched controls. Proportional to the reported female predominance among patients with fibromyalgia,²⁷ 4479 (90.1%) patients with fibromyalgia were females and a similar proportion was documented among controls (P=.99). There was a slightly higher proportion of unmarried patients among those with fibromyalgia compared with controls (41.9% vs 39.4%; P=.004). Socioeconomic status was matched between patients and controls (P=.99). Descriptive characteristics of the study population are presented in Table 1.

We assessed the presence of pruritus as well as 3 other pruritus-related skin disorders—prurigo nodularis, neurotic excoriations, and LSC—among patients with fibromyalgia and controls. Logistic regression was used to evaluate the independent association between fibromyalgia and pruritus. Table 2 presents the results of multivariate logistic regression models and summarizes the adjusted ORs for pruritic conditions in patients with fibromyalgia and different demographic features across the entire study sample. Fibromyalgia demonstrated strong independent associations with pruritus (OR, 1.8; 95% CI, 1.8-2.4; P<.001), prurigo nodularis (OR, 2.9; 95% CI, 1.1-8.4; P=.038), and LSC (OR, 1.5; 95% CI, 1.1-2.1; P=.01); the association with neurotic excoriations was not significant. Female sex significantly increased the risk for pruritus (OR 1.3; 95% CI, 1.0-1.6; P=.039), while age slightly increased the odds for pruritus (OR, 1.0; 95% CI, 1.0-1.04; P<.001), neurotic excoriations (OR, 1.0; 95% CI, 1.0-1.1; P=.046), and LSC (OR, 1.0; 95% CI, 1.01-1.04; P=.006). Finally, socioeconomic status was inversely correlated with pruritus (OR, 1.1; 95% CI, 1.1-1.5; P=.002).

Comment

A wide range of skin manifestations have been associated with fibromyalgia, but the exact mechanisms remain unclear. Nevertheless, it is conceivable that autonomic nervous system dysfunction,^28-31 amplified cutaneous opioid receptor activity,³² and an elevated presence of cutaneous mast cells with excessive degranulation may partially explain the frequent occurrence of pruritus and related skin disorders such as neurotic excoriations, prurigo nodularis, and LSC in individuals with fibromyalgia.^15,16 In line with these findings, our study—which was based on data from the largest health maintenance organization in Israel—demonstrated an increased prevalence of pruritus and related pruritic disorders among individuals diagnosed with fibromyalgia.

This cross-sectional study links pruritus with fibromyalgia. Few preliminary epidemiologic studies have shown an increased occurrence of cutaneous manifestations in patients with fibromyalgia. One chart review that looked at skin findings in patients with fibromyalgia revealed 32 distinct cutaneous manifestations, and pruritus was the major concern in 3.3% of 845 patients.¹⁵

A focused cross-sectional study involving only women (66 with fibromyalgia and 79 healthy controls) discovered 14 skin conditions that were more common in those with fibromyalgia. Notably, xerosis and neurotic excoriations were more prevalent compared to the control group.¹⁶

The brain and the skin—both derivatives of the embryonic ectoderm^33,34—are linked by pruritus. Although itch has its dedicated neurons, there is a wide-ranging overlap of brain-activated areas between pain and itch,⁶ and the neural anatomy of pain and itch are closely related in both the peripheral and central nervous systems^35-37; for example, diseases of the central nervous system are accompanied by pruritus in as many as 15% of cases, while postherpetic neuralgia can result in chronic pain, itching, or a combination of both.^38,39 Other instances include notalgia paresthetica and brachioradial pruritus.³⁸ Additionally, there is a noteworthy psychologic impact associated with both itch and pain,^40,41 with both psychosomatic and psychologic factors implicated in chronic pruritus and in fibromyalgia.⁴² Lastly, the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system are altered in both fibromyalgia and pruritus.^43-45

Tey et al⁴⁵ characterized the itch experienced in fibromyalgia as functional, which is described as pruritus associated with a somatoform disorder. In our study, we found a higher prevalence of pruritus among patients with fibromyalgia, and this association remained significant (P<.05) even when excluding other pruritic skin conditions and systemic diseases that can trigger itching. In addition, our logistic regression analyses revealed independent associations between fibromyalgia and pruritus, prurigo nodularis, and LSC.

According to Twycross et al,⁴⁶ there are 4 clinical categories of itch, which may coexist⁷: pruritoceptive (originating in the skin), neuropathic (originating in pathology located along the afferent pathway), neurogenic (central origin but lacks a neural pathology), and psychogenic.⁴⁷ Skin biopsy findings in patients with fibromyalgia include increased mast cell counts¹¹ and degranulation,⁴⁸ increased expression of δ and κ opioid receptors,³² vasoconstriction within tender points,⁴⁹ and elevated IL-1β, IL-6, or tumor necrosis factor α by reverse transcriptase-polymerase chain reaction.¹² A case recently was presented by Görg et al⁵⁰ involving a female patient with fibromyalgia who had been experiencing chronic pruritus, which the authors attributed to small-fiber neuropathy based on evidence from a skin biopsy indicating a reduced number of intraepidermal nerves and the fact that the itching originated around tender points. Altogether, the observed alterations may work together to make patients with fibromyalgia more susceptible to various skin-related comorbidities in general, especially those related to pruritus. Eventually, it might be the case that several itch categories and related pathomechanisms are involved in the pruritus phenotype of patients with fibromyalgia.

Age-related alterations in nerve fibers, lower immune function, xerosis, polypharmacy, and increased frequency of systemic diseases with age are just a few of the factors that may predispose older individuals to pruritus.^51,52 Indeed, our logistic regression model showed that age was significantly and independently associated with ­pruritus (P<.001), neurotic excoriations (P=.046), and LSC (P=.006). Female sex also was significantly linked with pruritus (P=.039). Intriguingly, high socioeconomic status was significantly associated with the diagnosis of ­pruritus (P=.002), possibly due to easier access to medical care.

There is a considerable overlap between the therapeutic approaches used in pruritus, pruritus-related skin disorders, and fibromyalgia. Antidepressants, anxiolytics, analgesics, and antiepileptics have been used to address both conditions.⁴⁵ The association between these conditions advocates for a multidisciplinary approach in patients with fibromyalgia and potentially supports the rationale for unified therapeutics for both conditions.

Conclusion

Our findings indicate an association between fibromyalgia and pruritus as well as associated pruritic skin disorders. Given the convoluted and largely undiscovered mechanisms underlying fibromyalgia, managing patients with this condition may present substantial challenges.⁵³ The data presented here support the implementation of a multidisciplinary treatment approach for patients with fibromyalgia. This approach should focus on managing fibromyalgia pain as well as addressing its concurrent skin-related conditions. It is advisable to consider treatments such as antiepileptics (eg, pregabalin, gabapentin) that specifically target neuropathic disorders in affected patients. These treatments may hold promise for alleviating fibromyalgia-related pain⁵⁴ and mitigating its related cutaneous comorbidities, especially pruritus.

Pruritus, which is defined as an itching sensation that elicits a desire to scratch, is the most common cutaneous condition. Pruritus is considered chronic when it lasts for more than 6 weeks.¹ Etiologies implicated in chronic pruritus include but are not limited to primary skin diseases such as atopic dermatitis, systemic causes, neuropathic disorders, and psychogenic reasons.² In approximately 8% to 35% of patients, the cause of pruritus remains elusive despite intensive investigation.³ The mechanisms of itch are multifaceted and include complex neural pathways.⁴ Although itch and pain share many similarities, they have distinct pathways based on their spinal connections.⁵ Nevertheless, both conditions show a wide overlap of receptors on peripheral nerve endings and activated brain parts.^6,7 Fibromyalgia, the third most common musculoskeletal condition, affects 2% to 3% of the population worldwide and is at least 7 times more common in females.^8,9 Its pathogenesis is not entirely clear but is thought to involve neurogenic inflammation, aberrations in peripheral nerves, and central pain mechanisms. Fibromyalgia is characterized by a plethora of symptoms including chronic widespread pain, autonomic disturbances, persistent fatigue and sleep disturbances, and hyperalgesia, as well as somatic and psychiatric symptoms.¹⁰

Fibromyalgia is accompanied by altered skin features including increased counts of mast cells and excessive degranulation,¹¹ neurogenic inflammation with elevated cytokine expression,¹² disrupted collagen metabolism,¹³ and microcirculation abnormalities.¹⁴ There has been limited research exploring the dermatologic manifestations of fibromyalgia. One retrospective study that included 845 patients with fibromyalgia reported increased occurrence of “neurodermatoses,” including pruritus, neurotic excoriations, prurigo nodules, and lichen simplex chronicus (LSC), among other cutaneous comorbidities.¹⁵ Another small study demonstrated an increased incidence of xerosis and neurotic excoriations in females with fibromyalgia.¹⁶ A paucity of large epidemiologic studies demonstrating the fibromyalgia-pruritus connection may lead to misdiagnosis, misinterpretation, and undertreatment of these patients.

Up to 49% of fibromyalgia patients experience small-fiber neuropathy.¹⁷ Electrophysiologic measurements, quantitative sensory testing, pain-related evoked potentials, and skin biopsies showed that patients with fibromyalgia have compromised small-fiber function, impaired pathways carrying fiber pain signals, and reduced skin innervation and regenerating fibers.^18,19 Accordingly, pruritus that has been reported in fibromyalgia is believed to be of neuropathic origin.¹⁵ Overall, it is suspected that the same mechanism that causes hypersensitivity and pain in fibromyalgia patients also predisposes them to pruritus. Similar systemic treatments (eg, analgesics, antidepressants, anticonvulsants) prescribed for both conditions support this theory.^20-25

Our large cross-sectional study sought to establish the association between fibromyalgia and pruritus as well as related pruritic conditions.

Methods

Study Design and Setting—We conducted a cross-­sectional retrospective study using data-mining techniques to access information from the Clalit Health Services (CHS) database. Clalit Health Services is the largest health maintenance organization in Israel. It encompasses an extensive database with continuous real-time input from medical, administrative, and pharmaceutical computerized operating systems, which helps facilitate data collection for epidemiologic studies. A chronic disease register is gathered from these data sources and continuously updated and validated through logistic checks. The current study was approved by the institutional review board of the CHS (approval #0212-17-com2). Informed consent was not required because the data were de-identified and this was a noninterventional observational study.

Study Population and Covariates—Medical records of CHS enrollees were screened for the diagnosis of fibromyalgia, and data on prevalent cases of fibromyalgia were retrieved. The diagnosis of fibromyalgia was based on the documentation of a fibromyalgia-specific diagnostic code registered by a board-certified rheumatologist. A control group of individuals without fibromyalgia was selected through 1:2 matching based on age, sex, and primary care clinic. The control group was randomly selected from the list of CHS members frequency-matched to cases, excluding case patients with fibromyalgia. Age matching was grounded on the exact year of birth (1-year strata).

Other covariates in the analysis included pruritus-related skin disorders, including prurigo nodularis, neurotic excoriations, and LSC. There were 3 socioeconomic status categories according to patients' poverty index: low, intermediate, and high.²⁶

Statistical Analysis—The distribution of sociodemographic and clinical features was compared between patients with fibromyalgia and controls using the χ² test for sex and socioeconomic status and the t test for age. Conditional logistic regression then was used to calculate adjusted odds ratio (OR) and 95% CI to compare patients with fibromyalgia and controls with respect to the presence of pruritic comorbidities. All statistical analyses were performed using SPSS software (version 26). P<.05 was considered statistically significant in all tests.

Results

Our study population comprised 4971 patients with fibromyalgia and 9896 age- and sex-matched controls. Proportional to the reported female predominance among patients with fibromyalgia,²⁷ 4479 (90.1%) patients with fibromyalgia were females and a similar proportion was documented among controls (P=.99). There was a slightly higher proportion of unmarried patients among those with fibromyalgia compared with controls (41.9% vs 39.4%; P=.004). Socioeconomic status was matched between patients and controls (P=.99). Descriptive characteristics of the study population are presented in Table 1.

We assessed the presence of pruritus as well as 3 other pruritus-related skin disorders—prurigo nodularis, neurotic excoriations, and LSC—among patients with fibromyalgia and controls. Logistic regression was used to evaluate the independent association between fibromyalgia and pruritus. Table 2 presents the results of multivariate logistic regression models and summarizes the adjusted ORs for pruritic conditions in patients with fibromyalgia and different demographic features across the entire study sample. Fibromyalgia demonstrated strong independent associations with pruritus (OR, 1.8; 95% CI, 1.8-2.4; P<.001), prurigo nodularis (OR, 2.9; 95% CI, 1.1-8.4; P=.038), and LSC (OR, 1.5; 95% CI, 1.1-2.1; P=.01); the association with neurotic excoriations was not significant. Female sex significantly increased the risk for pruritus (OR 1.3; 95% CI, 1.0-1.6; P=.039), while age slightly increased the odds for pruritus (OR, 1.0; 95% CI, 1.0-1.04; P<.001), neurotic excoriations (OR, 1.0; 95% CI, 1.0-1.1; P=.046), and LSC (OR, 1.0; 95% CI, 1.01-1.04; P=.006). Finally, socioeconomic status was inversely correlated with pruritus (OR, 1.1; 95% CI, 1.1-1.5; P=.002).

Comment

A wide range of skin manifestations have been associated with fibromyalgia, but the exact mechanisms remain unclear. Nevertheless, it is conceivable that autonomic nervous system dysfunction,^28-31 amplified cutaneous opioid receptor activity,³² and an elevated presence of cutaneous mast cells with excessive degranulation may partially explain the frequent occurrence of pruritus and related skin disorders such as neurotic excoriations, prurigo nodularis, and LSC in individuals with fibromyalgia.^15,16 In line with these findings, our study—which was based on data from the largest health maintenance organization in Israel—demonstrated an increased prevalence of pruritus and related pruritic disorders among individuals diagnosed with fibromyalgia.

This cross-sectional study links pruritus with fibromyalgia. Few preliminary epidemiologic studies have shown an increased occurrence of cutaneous manifestations in patients with fibromyalgia. One chart review that looked at skin findings in patients with fibromyalgia revealed 32 distinct cutaneous manifestations, and pruritus was the major concern in 3.3% of 845 patients.¹⁵

A focused cross-sectional study involving only women (66 with fibromyalgia and 79 healthy controls) discovered 14 skin conditions that were more common in those with fibromyalgia. Notably, xerosis and neurotic excoriations were more prevalent compared to the control group.¹⁶

The brain and the skin—both derivatives of the embryonic ectoderm^33,34—are linked by pruritus. Although itch has its dedicated neurons, there is a wide-ranging overlap of brain-activated areas between pain and itch,⁶ and the neural anatomy of pain and itch are closely related in both the peripheral and central nervous systems^35-37; for example, diseases of the central nervous system are accompanied by pruritus in as many as 15% of cases, while postherpetic neuralgia can result in chronic pain, itching, or a combination of both.^38,39 Other instances include notalgia paresthetica and brachioradial pruritus.³⁸ Additionally, there is a noteworthy psychologic impact associated with both itch and pain,^40,41 with both psychosomatic and psychologic factors implicated in chronic pruritus and in fibromyalgia.⁴² Lastly, the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system are altered in both fibromyalgia and pruritus.^43-45

Tey et al⁴⁵ characterized the itch experienced in fibromyalgia as functional, which is described as pruritus associated with a somatoform disorder. In our study, we found a higher prevalence of pruritus among patients with fibromyalgia, and this association remained significant (P<.05) even when excluding other pruritic skin conditions and systemic diseases that can trigger itching. In addition, our logistic regression analyses revealed independent associations between fibromyalgia and pruritus, prurigo nodularis, and LSC.

According to Twycross et al,⁴⁶ there are 4 clinical categories of itch, which may coexist⁷: pruritoceptive (originating in the skin), neuropathic (originating in pathology located along the afferent pathway), neurogenic (central origin but lacks a neural pathology), and psychogenic.⁴⁷ Skin biopsy findings in patients with fibromyalgia include increased mast cell counts¹¹ and degranulation,⁴⁸ increased expression of δ and κ opioid receptors,³² vasoconstriction within tender points,⁴⁹ and elevated IL-1β, IL-6, or tumor necrosis factor α by reverse transcriptase-polymerase chain reaction.¹² A case recently was presented by Görg et al⁵⁰ involving a female patient with fibromyalgia who had been experiencing chronic pruritus, which the authors attributed to small-fiber neuropathy based on evidence from a skin biopsy indicating a reduced number of intraepidermal nerves and the fact that the itching originated around tender points. Altogether, the observed alterations may work together to make patients with fibromyalgia more susceptible to various skin-related comorbidities in general, especially those related to pruritus. Eventually, it might be the case that several itch categories and related pathomechanisms are involved in the pruritus phenotype of patients with fibromyalgia.

Age-related alterations in nerve fibers, lower immune function, xerosis, polypharmacy, and increased frequency of systemic diseases with age are just a few of the factors that may predispose older individuals to pruritus.^51,52 Indeed, our logistic regression model showed that age was significantly and independently associated with ­pruritus (P<.001), neurotic excoriations (P=.046), and LSC (P=.006). Female sex also was significantly linked with pruritus (P=.039). Intriguingly, high socioeconomic status was significantly associated with the diagnosis of ­pruritus (P=.002), possibly due to easier access to medical care.

There is a considerable overlap between the therapeutic approaches used in pruritus, pruritus-related skin disorders, and fibromyalgia. Antidepressants, anxiolytics, analgesics, and antiepileptics have been used to address both conditions.⁴⁵ The association between these conditions advocates for a multidisciplinary approach in patients with fibromyalgia and potentially supports the rationale for unified therapeutics for both conditions.

Conclusion

Our findings indicate an association between fibromyalgia and pruritus as well as associated pruritic skin disorders. Given the convoluted and largely undiscovered mechanisms underlying fibromyalgia, managing patients with this condition may present substantial challenges.⁵³ The data presented here support the implementation of a multidisciplinary treatment approach for patients with fibromyalgia. This approach should focus on managing fibromyalgia pain as well as addressing its concurrent skin-related conditions. It is advisable to consider treatments such as antiepileptics (eg, pregabalin, gabapentin) that specifically target neuropathic disorders in affected patients. These treatments may hold promise for alleviating fibromyalgia-related pain⁵⁴ and mitigating its related cutaneous comorbidities, especially pruritus.

Pruritus, which is defined as an itching sensation that elicits a desire to scratch, is the most common cutaneous condition. Pruritus is considered chronic when it lasts for more than 6 weeks.¹ Etiologies implicated in chronic pruritus include but are not limited to primary skin diseases such as atopic dermatitis, systemic causes, neuropathic disorders, and psychogenic reasons.² In approximately 8% to 35% of patients, the cause of pruritus remains elusive despite intensive investigation.³ The mechanisms of itch are multifaceted and include complex neural pathways.⁴ Although itch and pain share many similarities, they have distinct pathways based on their spinal connections.⁵ Nevertheless, both conditions show a wide overlap of receptors on peripheral nerve endings and activated brain parts.^6,7 Fibromyalgia, the third most common musculoskeletal condition, affects 2% to 3% of the population worldwide and is at least 7 times more common in females.^8,9 Its pathogenesis is not entirely clear but is thought to involve neurogenic inflammation, aberrations in peripheral nerves, and central pain mechanisms. Fibromyalgia is characterized by a plethora of symptoms including chronic widespread pain, autonomic disturbances, persistent fatigue and sleep disturbances, and hyperalgesia, as well as somatic and psychiatric symptoms.¹⁰

Fibromyalgia is accompanied by altered skin features including increased counts of mast cells and excessive degranulation,¹¹ neurogenic inflammation with elevated cytokine expression,¹² disrupted collagen metabolism,¹³ and microcirculation abnormalities.¹⁴ There has been limited research exploring the dermatologic manifestations of fibromyalgia. One retrospective study that included 845 patients with fibromyalgia reported increased occurrence of “neurodermatoses,” including pruritus, neurotic excoriations, prurigo nodules, and lichen simplex chronicus (LSC), among other cutaneous comorbidities.¹⁵ Another small study demonstrated an increased incidence of xerosis and neurotic excoriations in females with fibromyalgia.¹⁶ A paucity of large epidemiologic studies demonstrating the fibromyalgia-pruritus connection may lead to misdiagnosis, misinterpretation, and undertreatment of these patients.

Up to 49% of fibromyalgia patients experience small-fiber neuropathy.¹⁷ Electrophysiologic measurements, quantitative sensory testing, pain-related evoked potentials, and skin biopsies showed that patients with fibromyalgia have compromised small-fiber function, impaired pathways carrying fiber pain signals, and reduced skin innervation and regenerating fibers.^18,19 Accordingly, pruritus that has been reported in fibromyalgia is believed to be of neuropathic origin.¹⁵ Overall, it is suspected that the same mechanism that causes hypersensitivity and pain in fibromyalgia patients also predisposes them to pruritus. Similar systemic treatments (eg, analgesics, antidepressants, anticonvulsants) prescribed for both conditions support this theory.^20-25

Our large cross-sectional study sought to establish the association between fibromyalgia and pruritus as well as related pruritic conditions.

Methods

Study Design and Setting—We conducted a cross-­sectional retrospective study using data-mining techniques to access information from the Clalit Health Services (CHS) database. Clalit Health Services is the largest health maintenance organization in Israel. It encompasses an extensive database with continuous real-time input from medical, administrative, and pharmaceutical computerized operating systems, which helps facilitate data collection for epidemiologic studies. A chronic disease register is gathered from these data sources and continuously updated and validated through logistic checks. The current study was approved by the institutional review board of the CHS (approval #0212-17-com2). Informed consent was not required because the data were de-identified and this was a noninterventional observational study.

Study Population and Covariates—Medical records of CHS enrollees were screened for the diagnosis of fibromyalgia, and data on prevalent cases of fibromyalgia were retrieved. The diagnosis of fibromyalgia was based on the documentation of a fibromyalgia-specific diagnostic code registered by a board-certified rheumatologist. A control group of individuals without fibromyalgia was selected through 1:2 matching based on age, sex, and primary care clinic. The control group was randomly selected from the list of CHS members frequency-matched to cases, excluding case patients with fibromyalgia. Age matching was grounded on the exact year of birth (1-year strata).

Other covariates in the analysis included pruritus-related skin disorders, including prurigo nodularis, neurotic excoriations, and LSC. There were 3 socioeconomic status categories according to patients' poverty index: low, intermediate, and high.²⁶

Statistical Analysis—The distribution of sociodemographic and clinical features was compared between patients with fibromyalgia and controls using the χ² test for sex and socioeconomic status and the t test for age. Conditional logistic regression then was used to calculate adjusted odds ratio (OR) and 95% CI to compare patients with fibromyalgia and controls with respect to the presence of pruritic comorbidities. All statistical analyses were performed using SPSS software (version 26). P<.05 was considered statistically significant in all tests.

Results

Our study population comprised 4971 patients with fibromyalgia and 9896 age- and sex-matched controls. Proportional to the reported female predominance among patients with fibromyalgia,²⁷ 4479 (90.1%) patients with fibromyalgia were females and a similar proportion was documented among controls (P=.99). There was a slightly higher proportion of unmarried patients among those with fibromyalgia compared with controls (41.9% vs 39.4%; P=.004). Socioeconomic status was matched between patients and controls (P=.99). Descriptive characteristics of the study population are presented in Table 1.

We assessed the presence of pruritus as well as 3 other pruritus-related skin disorders—prurigo nodularis, neurotic excoriations, and LSC—among patients with fibromyalgia and controls. Logistic regression was used to evaluate the independent association between fibromyalgia and pruritus. Table 2 presents the results of multivariate logistic regression models and summarizes the adjusted ORs for pruritic conditions in patients with fibromyalgia and different demographic features across the entire study sample. Fibromyalgia demonstrated strong independent associations with pruritus (OR, 1.8; 95% CI, 1.8-2.4; P<.001), prurigo nodularis (OR, 2.9; 95% CI, 1.1-8.4; P=.038), and LSC (OR, 1.5; 95% CI, 1.1-2.1; P=.01); the association with neurotic excoriations was not significant. Female sex significantly increased the risk for pruritus (OR 1.3; 95% CI, 1.0-1.6; P=.039), while age slightly increased the odds for pruritus (OR, 1.0; 95% CI, 1.0-1.04; P<.001), neurotic excoriations (OR, 1.0; 95% CI, 1.0-1.1; P=.046), and LSC (OR, 1.0; 95% CI, 1.01-1.04; P=.006). Finally, socioeconomic status was inversely correlated with pruritus (OR, 1.1; 95% CI, 1.1-1.5; P=.002).

Comment

A wide range of skin manifestations have been associated with fibromyalgia, but the exact mechanisms remain unclear. Nevertheless, it is conceivable that autonomic nervous system dysfunction,^28-31 amplified cutaneous opioid receptor activity,³² and an elevated presence of cutaneous mast cells with excessive degranulation may partially explain the frequent occurrence of pruritus and related skin disorders such as neurotic excoriations, prurigo nodularis, and LSC in individuals with fibromyalgia.^15,16 In line with these findings, our study—which was based on data from the largest health maintenance organization in Israel—demonstrated an increased prevalence of pruritus and related pruritic disorders among individuals diagnosed with fibromyalgia.

This cross-sectional study links pruritus with fibromyalgia. Few preliminary epidemiologic studies have shown an increased occurrence of cutaneous manifestations in patients with fibromyalgia. One chart review that looked at skin findings in patients with fibromyalgia revealed 32 distinct cutaneous manifestations, and pruritus was the major concern in 3.3% of 845 patients.¹⁵

A focused cross-sectional study involving only women (66 with fibromyalgia and 79 healthy controls) discovered 14 skin conditions that were more common in those with fibromyalgia. Notably, xerosis and neurotic excoriations were more prevalent compared to the control group.¹⁶

The brain and the skin—both derivatives of the embryonic ectoderm^33,34—are linked by pruritus. Although itch has its dedicated neurons, there is a wide-ranging overlap of brain-activated areas between pain and itch,⁶ and the neural anatomy of pain and itch are closely related in both the peripheral and central nervous systems^35-37; for example, diseases of the central nervous system are accompanied by pruritus in as many as 15% of cases, while postherpetic neuralgia can result in chronic pain, itching, or a combination of both.^38,39 Other instances include notalgia paresthetica and brachioradial pruritus.³⁸ Additionally, there is a noteworthy psychologic impact associated with both itch and pain,^40,41 with both psychosomatic and psychologic factors implicated in chronic pruritus and in fibromyalgia.⁴² Lastly, the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system are altered in both fibromyalgia and pruritus.^43-45

Tey et al⁴⁵ characterized the itch experienced in fibromyalgia as functional, which is described as pruritus associated with a somatoform disorder. In our study, we found a higher prevalence of pruritus among patients with fibromyalgia, and this association remained significant (P<.05) even when excluding other pruritic skin conditions and systemic diseases that can trigger itching. In addition, our logistic regression analyses revealed independent associations between fibromyalgia and pruritus, prurigo nodularis, and LSC.

According to Twycross et al,⁴⁶ there are 4 clinical categories of itch, which may coexist⁷: pruritoceptive (originating in the skin), neuropathic (originating in pathology located along the afferent pathway), neurogenic (central origin but lacks a neural pathology), and psychogenic.⁴⁷ Skin biopsy findings in patients with fibromyalgia include increased mast cell counts¹¹ and degranulation,⁴⁸ increased expression of δ and κ opioid receptors,³² vasoconstriction within tender points,⁴⁹ and elevated IL-1β, IL-6, or tumor necrosis factor α by reverse transcriptase-polymerase chain reaction.¹² A case recently was presented by Görg et al⁵⁰ involving a female patient with fibromyalgia who had been experiencing chronic pruritus, which the authors attributed to small-fiber neuropathy based on evidence from a skin biopsy indicating a reduced number of intraepidermal nerves and the fact that the itching originated around tender points. Altogether, the observed alterations may work together to make patients with fibromyalgia more susceptible to various skin-related comorbidities in general, especially those related to pruritus. Eventually, it might be the case that several itch categories and related pathomechanisms are involved in the pruritus phenotype of patients with fibromyalgia.

Age-related alterations in nerve fibers, lower immune function, xerosis, polypharmacy, and increased frequency of systemic diseases with age are just a few of the factors that may predispose older individuals to pruritus.^51,52 Indeed, our logistic regression model showed that age was significantly and independently associated with ­pruritus (P<.001), neurotic excoriations (P=.046), and LSC (P=.006). Female sex also was significantly linked with pruritus (P=.039). Intriguingly, high socioeconomic status was significantly associated with the diagnosis of ­pruritus (P=.002), possibly due to easier access to medical care.

There is a considerable overlap between the therapeutic approaches used in pruritus, pruritus-related skin disorders, and fibromyalgia. Antidepressants, anxiolytics, analgesics, and antiepileptics have been used to address both conditions.⁴⁵ The association between these conditions advocates for a multidisciplinary approach in patients with fibromyalgia and potentially supports the rationale for unified therapeutics for both conditions.

Conclusion

Our findings indicate an association between fibromyalgia and pruritus as well as associated pruritic skin disorders. Given the convoluted and largely undiscovered mechanisms underlying fibromyalgia, managing patients with this condition may present substantial challenges.⁵³ The data presented here support the implementation of a multidisciplinary treatment approach for patients with fibromyalgia. This approach should focus on managing fibromyalgia pain as well as addressing its concurrent skin-related conditions. It is advisable to consider treatments such as antiepileptics (eg, pregabalin, gabapentin) that specifically target neuropathic disorders in affected patients. These treatments may hold promise for alleviating fibromyalgia-related pain⁵⁴ and mitigating its related cutaneous comorbidities, especially pruritus.

The Diagnosis: Mycobacterium marinum Infection

A repeat excisional biopsy showed suppurative granulomatous dermatitis with negative stains for infectious organisms; however, tissue culture grew Mycobacterium marinum. The patient had a history of exposure to fish tanks, which are a potential habitat for nontuberculous mycobacteria. These bacteria can enter the body through a minor laceration or cut in the skin, which was likely due to her occupation and pet care activities.¹ Her fish tank exposure combined with the cutaneous findings of a long-standing indurated plaque with proximal nodular lymphangitis made M marinum infection the most likely diagnosis.²

Due to the limited specificity and sensitivity of patient symptoms, histologic staining, and direct microscopy, the gold standard for diagnosing acid-fast bacilli is tissue culture. ³ Tissue polymerase chain reaction testing is most useful in identifying the species of mycobacteria when histologic stains identify acid-fast bacilli but repeated tissue cultures are negative.⁴ With M marinum, a high clinical suspicion is needed to acquire a positive tissue culture because it needs to be grown for several weeks and at a temperature of 30 °C.⁵ Therefore, the physician should inform the laboratory if there is any suspicion for M marinum to increase the likelihood of obtaining a positive culture.

The differential diagnosis for M marinum infection includes other skin diseases that can cause nodular lymphangitis (also known as sporotrichoid spread) such as sporotrichosis, leishmaniasis, and certain bacterial and fungal infections. Although cat scratch disease, which is caused by Bartonella henselae, can appear similar to M marinum on histopathology, it clinically manifests with a single papulovesicular lesion at the site of inoculation that then forms a central eschar and resolves within a few weeks. Cat scratch disease typically causes painful lymphadenopathy, but it does not cause nodular lymphangitis or sporotrichoid spread.⁶ Sporotrichosis can have a similar clinical and histologic manifestation to M marinum infection, but the patient history typically includes exposure to Sporothrix schenckii through gardening or other contact with thorns, plants, or soil.² Cutaneous sarcoidosis can have a similar clinical appearance to M marinum infection, but nodular lymphangitis does not occur and histopathology would demonstrate noncaseating epithelioid cell granulomas.⁷ Lastly, although vegetative pyoderma gangrenosum can have some of the same histologic findings as M marinum, it typically also demonstrates sinus tract formation, which was not present in our case. Additionally, vegetative pyoderma gangrenosum manifests with a verrucous and pustular plaque that would not have lymphocutaneous spread.⁸

Treatment of cutaneous M marinum infection is guided by antibiotic susceptibility testing. One regimen is clarithromycin (500 mg twice daily⁹) plus ethambutol. ¹⁰ Treatment often entails a multidrug combination due to the high rates of antibiotic resistance. Other antibiotics that potentially can be used include rifampin, trimethoprim-sulfamethoxazole, minocycline, and quinolones. The treatment duration typically is more than 3 months, and therapy is continued for 4 to 6 weeks after the skin lesions resolve.¹¹ Excision of the lesion is reserved for patients with M marinum infection that fails to respond to antibiotic therapy.⁵

The Diagnosis: Mycobacterium marinum Infection

A repeat excisional biopsy showed suppurative granulomatous dermatitis with negative stains for infectious organisms; however, tissue culture grew Mycobacterium marinum. The patient had a history of exposure to fish tanks, which are a potential habitat for nontuberculous mycobacteria. These bacteria can enter the body through a minor laceration or cut in the skin, which was likely due to her occupation and pet care activities.¹ Her fish tank exposure combined with the cutaneous findings of a long-standing indurated plaque with proximal nodular lymphangitis made M marinum infection the most likely diagnosis.²

Due to the limited specificity and sensitivity of patient symptoms, histologic staining, and direct microscopy, the gold standard for diagnosing acid-fast bacilli is tissue culture. ³ Tissue polymerase chain reaction testing is most useful in identifying the species of mycobacteria when histologic stains identify acid-fast bacilli but repeated tissue cultures are negative.⁴ With M marinum, a high clinical suspicion is needed to acquire a positive tissue culture because it needs to be grown for several weeks and at a temperature of 30 °C.⁵ Therefore, the physician should inform the laboratory if there is any suspicion for M marinum to increase the likelihood of obtaining a positive culture.

The differential diagnosis for M marinum infection includes other skin diseases that can cause nodular lymphangitis (also known as sporotrichoid spread) such as sporotrichosis, leishmaniasis, and certain bacterial and fungal infections. Although cat scratch disease, which is caused by Bartonella henselae, can appear similar to M marinum on histopathology, it clinically manifests with a single papulovesicular lesion at the site of inoculation that then forms a central eschar and resolves within a few weeks. Cat scratch disease typically causes painful lymphadenopathy, but it does not cause nodular lymphangitis or sporotrichoid spread.⁶ Sporotrichosis can have a similar clinical and histologic manifestation to M marinum infection, but the patient history typically includes exposure to Sporothrix schenckii through gardening or other contact with thorns, plants, or soil.² Cutaneous sarcoidosis can have a similar clinical appearance to M marinum infection, but nodular lymphangitis does not occur and histopathology would demonstrate noncaseating epithelioid cell granulomas.⁷ Lastly, although vegetative pyoderma gangrenosum can have some of the same histologic findings as M marinum, it typically also demonstrates sinus tract formation, which was not present in our case. Additionally, vegetative pyoderma gangrenosum manifests with a verrucous and pustular plaque that would not have lymphocutaneous spread.⁸

Treatment of cutaneous M marinum infection is guided by antibiotic susceptibility testing. One regimen is clarithromycin (500 mg twice daily⁹) plus ethambutol. ¹⁰ Treatment often entails a multidrug combination due to the high rates of antibiotic resistance. Other antibiotics that potentially can be used include rifampin, trimethoprim-sulfamethoxazole, minocycline, and quinolones. The treatment duration typically is more than 3 months, and therapy is continued for 4 to 6 weeks after the skin lesions resolve.¹¹ Excision of the lesion is reserved for patients with M marinum infection that fails to respond to antibiotic therapy.⁵

The Diagnosis: Mycobacterium marinum Infection

A repeat excisional biopsy showed suppurative granulomatous dermatitis with negative stains for infectious organisms; however, tissue culture grew Mycobacterium marinum. The patient had a history of exposure to fish tanks, which are a potential habitat for nontuberculous mycobacteria. These bacteria can enter the body through a minor laceration or cut in the skin, which was likely due to her occupation and pet care activities.¹ Her fish tank exposure combined with the cutaneous findings of a long-standing indurated plaque with proximal nodular lymphangitis made M marinum infection the most likely diagnosis.²

Due to the limited specificity and sensitivity of patient symptoms, histologic staining, and direct microscopy, the gold standard for diagnosing acid-fast bacilli is tissue culture. ³ Tissue polymerase chain reaction testing is most useful in identifying the species of mycobacteria when histologic stains identify acid-fast bacilli but repeated tissue cultures are negative.⁴ With M marinum, a high clinical suspicion is needed to acquire a positive tissue culture because it needs to be grown for several weeks and at a temperature of 30 °C.⁵ Therefore, the physician should inform the laboratory if there is any suspicion for M marinum to increase the likelihood of obtaining a positive culture.

The differential diagnosis for M marinum infection includes other skin diseases that can cause nodular lymphangitis (also known as sporotrichoid spread) such as sporotrichosis, leishmaniasis, and certain bacterial and fungal infections. Although cat scratch disease, which is caused by Bartonella henselae, can appear similar to M marinum on histopathology, it clinically manifests with a single papulovesicular lesion at the site of inoculation that then forms a central eschar and resolves within a few weeks. Cat scratch disease typically causes painful lymphadenopathy, but it does not cause nodular lymphangitis or sporotrichoid spread.⁶ Sporotrichosis can have a similar clinical and histologic manifestation to M marinum infection, but the patient history typically includes exposure to Sporothrix schenckii through gardening or other contact with thorns, plants, or soil.² Cutaneous sarcoidosis can have a similar clinical appearance to M marinum infection, but nodular lymphangitis does not occur and histopathology would demonstrate noncaseating epithelioid cell granulomas.⁷ Lastly, although vegetative pyoderma gangrenosum can have some of the same histologic findings as M marinum, it typically also demonstrates sinus tract formation, which was not present in our case. Additionally, vegetative pyoderma gangrenosum manifests with a verrucous and pustular plaque that would not have lymphocutaneous spread.⁸

Treatment of cutaneous M marinum infection is guided by antibiotic susceptibility testing. One regimen is clarithromycin (500 mg twice daily⁹) plus ethambutol. ¹⁰ Treatment often entails a multidrug combination due to the high rates of antibiotic resistance. Other antibiotics that potentially can be used include rifampin, trimethoprim-sulfamethoxazole, minocycline, and quinolones. The treatment duration typically is more than 3 months, and therapy is continued for 4 to 6 weeks after the skin lesions resolve.¹¹ Excision of the lesion is reserved for patients with M marinum infection that fails to respond to antibiotic therapy.⁵

The clinical manifestations of snakebites vary based on the species of snake, bite location, and amount and strength of the venom injected. Locally acting toxins in snake venom predominantly consist of enzymes, such as phospholipase A₂, that cause local tissue destruction and can result in pain, swelling, blistering, ecchymosis, and tissue necrosis at the site of the bite within hours to days after the bite.¹ Systemically acting toxins can target a wide variety of tissues and cause severe systemic complications including paralysis, rhabdomyolysis secondary to muscle damage, coagulopathy, sepsis, and cardiorespiratory failure.²

Although pain and swelling following snakebites typically resolve by 1 month after envenomation, copperhead snakes—a type of pit viper—may cause residual symptoms of pain and swelling lasting for a year or more.³ Additional cutaneous manifestations of copperhead snakebites include wound infections at the bite site, such as cellulitis and necrotizing fasciitis. More devastating complications that have been described following snake envenomation include tissue injury of an entire extremity and development of compartment syndrome, which requires urgent fasciotomy to prevent potential loss of the affected limb.⁴

Physicians should be aware of the potential complications of snakebites to properly manage and counsel their patients. We describe a 42-year-old woman with tender, erythematous, subcutaneous nodules persisting for 4 months following a copperhead snakebite. A biopsy confirmed the diagnosis of snakebite-associated erythema nodosum (EN).

Case Report

A 42-year-old woman presented to our clinic with progressive tender, pruritic, deep-seated, erythematous nodules in multiple locations on the legs after sustaining a bite by a copperhead snake on the left foot 4 months prior. The lesions tended to fluctuate in intensity. In the days following the bite, she initially developed painful red bumps on the left foot just proximal to the bite site with associated pain and swelling extending up to just below the left knee. She reported no other notable symptoms such as fever, arthralgia, fatigue, or gastrointestinal tract symptoms. Physical examination revealed bilateral pitting edema, which was worse in the left leg, along with multiple deep, palpable, tender subcutaneous nodules with erythematous surface change (Figure 1).

Workup performed by an outside provider over the previous month included 2 venous duplex ultrasounds of the left leg, which showed no signs of deep vein thrombosis. Additionally, the patient underwent lateral and anteroposterior radiographs of the left foot, tibia, and fibula, which showed no evidence of fracture.

Given the morphology and distribution of the lesions (Figure 2), EN was strongly favored as the cause of the symptoms, and a biopsy confirmed the diagnosis. All immunohistochemical stains including auramine-­rhodamine for acid-fast bacilli, Grocott-Gomori methenamine silver for fungal organisms, and Brown and Brenn were negative. Given the waxing and waning course of the lesions, which suggested an active neutrophilic rather than purely chronic granulomatous phase of EN, the patient was treated with colchicine 0.6 mg twice daily for 1 month.

Causes of EN and Clinical Manifestations

Erythema nodosum is a common form of septal panniculitis that can be precipitated by inflammatory conditions, infection, or medications (commonly oral contraceptive pills) but often is idiopathic.⁵ The acute phase is neutrophilic, with evolution over time to a granulomatous phase. Common etiologies include sarcoidosis; inflammatory bowel disease; and bacterial or fungal infections such as Streptococcus (especially common in children), histoplasmosis, and coccidioidomycosis. The patient was otherwise healthy and was not taking any medications that are known triggers of EN. A PubMed search of articles indexed for MEDLINE in the English-language literature using the terms copperhead snake bite, erythema nodosum snake, and copperhead snake erythema nodosum revealed no reports of EN following a bite from a copperhead snake; however, in one case, an adder bite led to erysipelas, likely due to disturbed blood and lymphatic flow, which then triggered EN.⁶ Additionally, EN has been reported as a delayed reaction to jellyfish stings.⁷

Clinical features of EN include the development of tender, erythematous, subcutaneous nodules and plaques most frequently over the pretibial region. Lesions typically evolve from raised, deep-seated nodules into flat indurated plaques over a span of weeks. Occasionally, there is a slight prodromal phase marked by nonspecific symptoms such as fever and arthralgia lasting for 3 to 6 days. Erythema nodosum typically results in spontaneous resolution after 4 to 8 weeks, and management involves treatment of any underlying condition with symptomatic care. Interestingly, our patient experienced persistent symptoms over the course of 4 months, with development of new nodular lesions throughout this time period. The most frequently used drugs for the management of symptomatic EN include nonsteroidal anti-inflammatory drugs, colchicine, and potassium iodide.⁸ A characteristic histologic finding of the granulomatous phase is the Miescher radial granuloma, which is a septal collection of histiocytes surrounding a cleft.⁹

Snakebite Reactions

Snakebites can result in a wide range of local and systemic manifestations, as snake venom may contain 20 or more toxins.¹⁰ Local complications of pit viper bites include pain, swelling, and fang marks; when examining fang marks, the presence of 2 distinct puncture wounds often indicates envenomation with a poisonous snake, whereas nonvenomous snakebites often result in smaller puncture wounds arranged in an arc. Following bites, pain can develop immediately and spread proximally up the affected limb, which occurred in our patient in the days following the bite. Intense local reactions can occur, as bites often result in intense edema of the affected limb spreading to the trunk in the days to weeks after the bite, occasionally accompanied by regional lymphadenopathy. Some bites can result in local necrosis and secondary bacterial infection caused by organisms in the oral cavity of the culprit snake.

Although they were not present in our patient, snakebites can result in a wide range of systemic toxicities ranging from clotting defects and hemolysis to neurotoxicity, myotoxicity, and nephrotoxicity.¹⁰ In severe cases, snake venom can result in disseminated intravascular coagulation, sepsis, and cardiorespiratory collapse.

The eastern copperhead (Agkistrodon contortrix) is a species of venomous snake that is endemic to eastern North America. Copperheads are members of the subfamily Crotalinae in the family Viperidae.¹¹ Reported reactions to copperhead bites include cellulitis, necrotizing fasciitis, compartment syndrome, and tissue necrosis of an entire affected extremity.^12,13 Our patient displayed no systemic symptoms to suggest envenomation.

Management of Snakebites

Treatment of snakebites varies based on the constellation and severity of symptoms as well as how recently the envenomation occurred. In urgent cases, antivenom may be administered to prevent further toxicity. In cases of progressive compartment syndrome, emergent surgical procedures such as fasciotomy or amputation are required to prevent further complications. When a superimposed bacterial infection is suspected, broad-spectrum antibiotics are required. Because our patient presented 4 months following the initial bite with isolated cutaneous manifestations, she was treated symptomatically with colchicine for EN.^1,2

Final Thoughts

Our patient presented with EN following a bite from a copperhead snake. Physicians should be aware of possible etiologies of EN to evaluate patients who present with new-onset tender subcutaneous nodules. Additionally, physicians should be aware of venomous snakes endemic to their region and also understand the various complications that can result following a snakebite, with the potential for lingering cutaneous manifestations weeks to months following the initial bite.

The clinical manifestations of snakebites vary based on the species of snake, bite location, and amount and strength of the venom injected. Locally acting toxins in snake venom predominantly consist of enzymes, such as phospholipase A₂, that cause local tissue destruction and can result in pain, swelling, blistering, ecchymosis, and tissue necrosis at the site of the bite within hours to days after the bite.¹ Systemically acting toxins can target a wide variety of tissues and cause severe systemic complications including paralysis, rhabdomyolysis secondary to muscle damage, coagulopathy, sepsis, and cardiorespiratory failure.²

Although pain and swelling following snakebites typically resolve by 1 month after envenomation, copperhead snakes—a type of pit viper—may cause residual symptoms of pain and swelling lasting for a year or more.³ Additional cutaneous manifestations of copperhead snakebites include wound infections at the bite site, such as cellulitis and necrotizing fasciitis. More devastating complications that have been described following snake envenomation include tissue injury of an entire extremity and development of compartment syndrome, which requires urgent fasciotomy to prevent potential loss of the affected limb.⁴

Physicians should be aware of the potential complications of snakebites to properly manage and counsel their patients. We describe a 42-year-old woman with tender, erythematous, subcutaneous nodules persisting for 4 months following a copperhead snakebite. A biopsy confirmed the diagnosis of snakebite-associated erythema nodosum (EN).

Case Report

A 42-year-old woman presented to our clinic with progressive tender, pruritic, deep-seated, erythematous nodules in multiple locations on the legs after sustaining a bite by a copperhead snake on the left foot 4 months prior. The lesions tended to fluctuate in intensity. In the days following the bite, she initially developed painful red bumps on the left foot just proximal to the bite site with associated pain and swelling extending up to just below the left knee. She reported no other notable symptoms such as fever, arthralgia, fatigue, or gastrointestinal tract symptoms. Physical examination revealed bilateral pitting edema, which was worse in the left leg, along with multiple deep, palpable, tender subcutaneous nodules with erythematous surface change (Figure 1).

Workup performed by an outside provider over the previous month included 2 venous duplex ultrasounds of the left leg, which showed no signs of deep vein thrombosis. Additionally, the patient underwent lateral and anteroposterior radiographs of the left foot, tibia, and fibula, which showed no evidence of fracture.

Given the morphology and distribution of the lesions (Figure 2), EN was strongly favored as the cause of the symptoms, and a biopsy confirmed the diagnosis. All immunohistochemical stains including auramine-­rhodamine for acid-fast bacilli, Grocott-Gomori methenamine silver for fungal organisms, and Brown and Brenn were negative. Given the waxing and waning course of the lesions, which suggested an active neutrophilic rather than purely chronic granulomatous phase of EN, the patient was treated with colchicine 0.6 mg twice daily for 1 month.

Causes of EN and Clinical Manifestations

Erythema nodosum is a common form of septal panniculitis that can be precipitated by inflammatory conditions, infection, or medications (commonly oral contraceptive pills) but often is idiopathic.⁵ The acute phase is neutrophilic, with evolution over time to a granulomatous phase. Common etiologies include sarcoidosis; inflammatory bowel disease; and bacterial or fungal infections such as Streptococcus (especially common in children), histoplasmosis, and coccidioidomycosis. The patient was otherwise healthy and was not taking any medications that are known triggers of EN. A PubMed search of articles indexed for MEDLINE in the English-language literature using the terms copperhead snake bite, erythema nodosum snake, and copperhead snake erythema nodosum revealed no reports of EN following a bite from a copperhead snake; however, in one case, an adder bite led to erysipelas, likely due to disturbed blood and lymphatic flow, which then triggered EN.⁶ Additionally, EN has been reported as a delayed reaction to jellyfish stings.⁷

Clinical features of EN include the development of tender, erythematous, subcutaneous nodules and plaques most frequently over the pretibial region. Lesions typically evolve from raised, deep-seated nodules into flat indurated plaques over a span of weeks. Occasionally, there is a slight prodromal phase marked by nonspecific symptoms such as fever and arthralgia lasting for 3 to 6 days. Erythema nodosum typically results in spontaneous resolution after 4 to 8 weeks, and management involves treatment of any underlying condition with symptomatic care. Interestingly, our patient experienced persistent symptoms over the course of 4 months, with development of new nodular lesions throughout this time period. The most frequently used drugs for the management of symptomatic EN include nonsteroidal anti-inflammatory drugs, colchicine, and potassium iodide.⁸ A characteristic histologic finding of the granulomatous phase is the Miescher radial granuloma, which is a septal collection of histiocytes surrounding a cleft.⁹

Snakebite Reactions

Snakebites can result in a wide range of local and systemic manifestations, as snake venom may contain 20 or more toxins.¹⁰ Local complications of pit viper bites include pain, swelling, and fang marks; when examining fang marks, the presence of 2 distinct puncture wounds often indicates envenomation with a poisonous snake, whereas nonvenomous snakebites often result in smaller puncture wounds arranged in an arc. Following bites, pain can develop immediately and spread proximally up the affected limb, which occurred in our patient in the days following the bite. Intense local reactions can occur, as bites often result in intense edema of the affected limb spreading to the trunk in the days to weeks after the bite, occasionally accompanied by regional lymphadenopathy. Some bites can result in local necrosis and secondary bacterial infection caused by organisms in the oral cavity of the culprit snake.

Although they were not present in our patient, snakebites can result in a wide range of systemic toxicities ranging from clotting defects and hemolysis to neurotoxicity, myotoxicity, and nephrotoxicity.¹⁰ In severe cases, snake venom can result in disseminated intravascular coagulation, sepsis, and cardiorespiratory collapse.

The eastern copperhead (Agkistrodon contortrix) is a species of venomous snake that is endemic to eastern North America. Copperheads are members of the subfamily Crotalinae in the family Viperidae.¹¹ Reported reactions to copperhead bites include cellulitis, necrotizing fasciitis, compartment syndrome, and tissue necrosis of an entire affected extremity.^12,13 Our patient displayed no systemic symptoms to suggest envenomation.

Management of Snakebites

Treatment of snakebites varies based on the constellation and severity of symptoms as well as how recently the envenomation occurred. In urgent cases, antivenom may be administered to prevent further toxicity. In cases of progressive compartment syndrome, emergent surgical procedures such as fasciotomy or amputation are required to prevent further complications. When a superimposed bacterial infection is suspected, broad-spectrum antibiotics are required. Because our patient presented 4 months following the initial bite with isolated cutaneous manifestations, she was treated symptomatically with colchicine for EN.^1,2

Final Thoughts

Our patient presented with EN following a bite from a copperhead snake. Physicians should be aware of possible etiologies of EN to evaluate patients who present with new-onset tender subcutaneous nodules. Additionally, physicians should be aware of venomous snakes endemic to their region and also understand the various complications that can result following a snakebite, with the potential for lingering cutaneous manifestations weeks to months following the initial bite.

The clinical manifestations of snakebites vary based on the species of snake, bite location, and amount and strength of the venom injected. Locally acting toxins in snake venom predominantly consist of enzymes, such as phospholipase A₂, that cause local tissue destruction and can result in pain, swelling, blistering, ecchymosis, and tissue necrosis at the site of the bite within hours to days after the bite.¹ Systemically acting toxins can target a wide variety of tissues and cause severe systemic complications including paralysis, rhabdomyolysis secondary to muscle damage, coagulopathy, sepsis, and cardiorespiratory failure.²

Although pain and swelling following snakebites typically resolve by 1 month after envenomation, copperhead snakes—a type of pit viper—may cause residual symptoms of pain and swelling lasting for a year or more.³ Additional cutaneous manifestations of copperhead snakebites include wound infections at the bite site, such as cellulitis and necrotizing fasciitis. More devastating complications that have been described following snake envenomation include tissue injury of an entire extremity and development of compartment syndrome, which requires urgent fasciotomy to prevent potential loss of the affected limb.⁴

Physicians should be aware of the potential complications of snakebites to properly manage and counsel their patients. We describe a 42-year-old woman with tender, erythematous, subcutaneous nodules persisting for 4 months following a copperhead snakebite. A biopsy confirmed the diagnosis of snakebite-associated erythema nodosum (EN).

Case Report

A 42-year-old woman presented to our clinic with progressive tender, pruritic, deep-seated, erythematous nodules in multiple locations on the legs after sustaining a bite by a copperhead snake on the left foot 4 months prior. The lesions tended to fluctuate in intensity. In the days following the bite, she initially developed painful red bumps on the left foot just proximal to the bite site with associated pain and swelling extending up to just below the left knee. She reported no other notable symptoms such as fever, arthralgia, fatigue, or gastrointestinal tract symptoms. Physical examination revealed bilateral pitting edema, which was worse in the left leg, along with multiple deep, palpable, tender subcutaneous nodules with erythematous surface change (Figure 1).

Workup performed by an outside provider over the previous month included 2 venous duplex ultrasounds of the left leg, which showed no signs of deep vein thrombosis. Additionally, the patient underwent lateral and anteroposterior radiographs of the left foot, tibia, and fibula, which showed no evidence of fracture.

Given the morphology and distribution of the lesions (Figure 2), EN was strongly favored as the cause of the symptoms, and a biopsy confirmed the diagnosis. All immunohistochemical stains including auramine-­rhodamine for acid-fast bacilli, Grocott-Gomori methenamine silver for fungal organisms, and Brown and Brenn were negative. Given the waxing and waning course of the lesions, which suggested an active neutrophilic rather than purely chronic granulomatous phase of EN, the patient was treated with colchicine 0.6 mg twice daily for 1 month.

Causes of EN and Clinical Manifestations

Erythema nodosum is a common form of septal panniculitis that can be precipitated by inflammatory conditions, infection, or medications (commonly oral contraceptive pills) but often is idiopathic.⁵ The acute phase is neutrophilic, with evolution over time to a granulomatous phase. Common etiologies include sarcoidosis; inflammatory bowel disease; and bacterial or fungal infections such as Streptococcus (especially common in children), histoplasmosis, and coccidioidomycosis. The patient was otherwise healthy and was not taking any medications that are known triggers of EN. A PubMed search of articles indexed for MEDLINE in the English-language literature using the terms copperhead snake bite, erythema nodosum snake, and copperhead snake erythema nodosum revealed no reports of EN following a bite from a copperhead snake; however, in one case, an adder bite led to erysipelas, likely due to disturbed blood and lymphatic flow, which then triggered EN.⁶ Additionally, EN has been reported as a delayed reaction to jellyfish stings.⁷

Clinical features of EN include the development of tender, erythematous, subcutaneous nodules and plaques most frequently over the pretibial region. Lesions typically evolve from raised, deep-seated nodules into flat indurated plaques over a span of weeks. Occasionally, there is a slight prodromal phase marked by nonspecific symptoms such as fever and arthralgia lasting for 3 to 6 days. Erythema nodosum typically results in spontaneous resolution after 4 to 8 weeks, and management involves treatment of any underlying condition with symptomatic care. Interestingly, our patient experienced persistent symptoms over the course of 4 months, with development of new nodular lesions throughout this time period. The most frequently used drugs for the management of symptomatic EN include nonsteroidal anti-inflammatory drugs, colchicine, and potassium iodide.⁸ A characteristic histologic finding of the granulomatous phase is the Miescher radial granuloma, which is a septal collection of histiocytes surrounding a cleft.⁹

Snakebite Reactions

Snakebites can result in a wide range of local and systemic manifestations, as snake venom may contain 20 or more toxins.¹⁰ Local complications of pit viper bites include pain, swelling, and fang marks; when examining fang marks, the presence of 2 distinct puncture wounds often indicates envenomation with a poisonous snake, whereas nonvenomous snakebites often result in smaller puncture wounds arranged in an arc. Following bites, pain can develop immediately and spread proximally up the affected limb, which occurred in our patient in the days following the bite. Intense local reactions can occur, as bites often result in intense edema of the affected limb spreading to the trunk in the days to weeks after the bite, occasionally accompanied by regional lymphadenopathy. Some bites can result in local necrosis and secondary bacterial infection caused by organisms in the oral cavity of the culprit snake.

Although they were not present in our patient, snakebites can result in a wide range of systemic toxicities ranging from clotting defects and hemolysis to neurotoxicity, myotoxicity, and nephrotoxicity.¹⁰ In severe cases, snake venom can result in disseminated intravascular coagulation, sepsis, and cardiorespiratory collapse.

The eastern copperhead (Agkistrodon contortrix) is a species of venomous snake that is endemic to eastern North America. Copperheads are members of the subfamily Crotalinae in the family Viperidae.¹¹ Reported reactions to copperhead bites include cellulitis, necrotizing fasciitis, compartment syndrome, and tissue necrosis of an entire affected extremity.^12,13 Our patient displayed no systemic symptoms to suggest envenomation.

Management of Snakebites

Treatment of snakebites varies based on the constellation and severity of symptoms as well as how recently the envenomation occurred. In urgent cases, antivenom may be administered to prevent further toxicity. In cases of progressive compartment syndrome, emergent surgical procedures such as fasciotomy or amputation are required to prevent further complications. When a superimposed bacterial infection is suspected, broad-spectrum antibiotics are required. Because our patient presented 4 months following the initial bite with isolated cutaneous manifestations, she was treated symptomatically with colchicine for EN.^1,2

Final Thoughts

Our patient presented with EN following a bite from a copperhead snake. Physicians should be aware of possible etiologies of EN to evaluate patients who present with new-onset tender subcutaneous nodules. Additionally, physicians should be aware of venomous snakes endemic to their region and also understand the various complications that can result following a snakebite, with the potential for lingering cutaneous manifestations weeks to months following the initial bite.

To the Editor:

Generalized bullous fixed drug eruption (GBFDE) is a rare subtype of fixed drug eruption (FDE) that manifests as widespread blisters and erosions following exposure to a causative drug.¹ Diagnostic criteria include involvement of at least 3 to 6 anatomic sites—head and neck, anterior trunk, posterior trunk, upper extremities, lower extremities, or genitalia—and more than 10% of the body surface area. It can be challenging to differentiate GBFDE from severe drug rashes such as Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) due to extensive body surface area involvement of blisters and erosions. Specific features distinguishing GBFDE from SJS/TEN include primary lesions consisting of larger erythematous to dusky, circular plaques that progress to bullae and coalesce into widespread erosions; history of FDE; lack of severe mucosal involvement; and better overall prognosis.² Treatment typically involves discontinuation of the culprit medication and supportive care; evidence for systemic therapies is not well established.

Our study aimed to characterize the clinical and demographic features of GBFDE in our institution to highlight potential key differences between this diagnosis and SJS/TEN. An electronic medical record search was performed to identify patients who were clinically diagnosed with GBFDE at New York-Presbyterian/Weill Cornell Medical Center (New York, New York) in both outpatient and inpatient settings from January 2015 to December 2022. This retrospective study was approved by the Weill Cornell Medicine institutional review board (#22-05024777).

Ten patients were identified and included in the analysis (eTable). The mean age of the patients was 56 years (range, 39–76 years). Seven (70%) patients had skin of color (non-White) and 6 (60%) were female. The mean body mass index was 35 (range, 20–57), and 7 (70%) patients were clinically obese (body mass index >30). Only 2 (20%) patients had a history of a documented drug eruption (hives and erythema multiforme), and no patients had a history of FDE. Erythematous dusky patches followed by rapid development of blisters were noted within 3 days of drug initiation in 40% (4/10) and within 5 days in 80% (8/10) of patients. Antibiotics were identified as likely inciting agents in 8 (80%) patients. Biopsies were obtained in 3 (30%) patients and all 3 demonstrated cytotoxic CD8⁺ interface dermatitis with marked epithelial necrosis, neutrophilia, eosinophilia, and melanophage accumulation. Fever was present at initial presentation in only 4 (40%) patients, and only 1 (10%) patient had oral mucosal involvement. All 10 patients had intertriginous involvement (axillae, 90% [9/10]; gluteal cleft, 80% [8/10]; groin, 80% [8/10]; inframammary folds, 20% [2/10]), and there was considerable flank involvement in 9 (90%) patients. All 10 patients had initial erythematous to dusky, circular patches on the trunk and proximal extremities that then denuded most dramatically in the intertriginous areas (Figure). Six (60%) patients received systemic therapy, including 5 patients treated with a single dose of etanercept 50 mg. In patients with continued progression, 1 or 2 additional doses of etanercept 50 mg were administered at 48- to 72-hour intervals until blistering halted. Treatment with etanercept resulted in clinical improvement in all 5 patients, and there were no identifiable adverse events. The mean hospital stay was 19.7 days (range, 1–63 days).

This study highlights notable demographic and clinical features of GBFDE that have not been widely described in the literature. Large erythematous and dusky patches with broad zones of blistering with particular localization to the neck, intertriginous areas, and flanks typically are not described in SJS/TEN and may be helpful in distinguishing these conditions from GBFDE. Mild or complete lack of mucosal and facial involvement as well as more rapid time from drug initiation to rash (as rapid as 1 day) were key factors that aided in distinguishing GBFDE from SJS/TEN in our patients. Although a history of FDE is considered a key characteristic in the diagnosis of GBFDE, none of our patients had a known history of FDE, suggesting GBFDE may be the initial manifestation of FDE in some patients. Histopathology showed similar findings consistent with FDE in the 3 patients in whom a biopsy was performed. The remaining patients were diagnosed clinically based on the presence of distinctive, perfectly circular, dusky plaques present at the periphery of larger denuded areas, which are characteristic of GBFDE. Lower levels of serum granulysin³ have been shown to help distinguish GBFDE from SJS/TEN, but this test is not readily available with time-sensitive results at most institutions, and exact diagnostic ranges for GBFDE vs SJS/TEN are not yet known.

Our study was limited by a small number of patients at a single institution. Another limitation was the retrospective design.

Interestingly, a high proportion of our patients were non-White and clinically obese, which are factors that should be considered for future research. Sixty percent (6/10) of the patients in our study were Black, which is a notable difference from our hospital’s general admission demographics with Black individuals constituting 12% of patients.⁴ Our study also highlighted the utility of etanercept, which has reported mortality benefits and decreased time to re-epithelialization in other severe blistering cutaneous drug reactions including SJS/TEN,⁵ as a potential therapeutic option in GBFDE.

It is imperative that clinicians recognize the differences between GBFDE and SJS/TEN, as correct diagnosis is crucial for identifying the most likely causative drug as well as providing accurate prognostic information and may have future therapeutic implications as we further understand the immunologic profiles of these severe blistering drug reactions.

To the Editor:

Generalized bullous fixed drug eruption (GBFDE) is a rare subtype of fixed drug eruption (FDE) that manifests as widespread blisters and erosions following exposure to a causative drug.¹ Diagnostic criteria include involvement of at least 3 to 6 anatomic sites—head and neck, anterior trunk, posterior trunk, upper extremities, lower extremities, or genitalia—and more than 10% of the body surface area. It can be challenging to differentiate GBFDE from severe drug rashes such as Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) due to extensive body surface area involvement of blisters and erosions. Specific features distinguishing GBFDE from SJS/TEN include primary lesions consisting of larger erythematous to dusky, circular plaques that progress to bullae and coalesce into widespread erosions; history of FDE; lack of severe mucosal involvement; and better overall prognosis.² Treatment typically involves discontinuation of the culprit medication and supportive care; evidence for systemic therapies is not well established.

Our study aimed to characterize the clinical and demographic features of GBFDE in our institution to highlight potential key differences between this diagnosis and SJS/TEN. An electronic medical record search was performed to identify patients who were clinically diagnosed with GBFDE at New York-Presbyterian/Weill Cornell Medical Center (New York, New York) in both outpatient and inpatient settings from January 2015 to December 2022. This retrospective study was approved by the Weill Cornell Medicine institutional review board (#22-05024777).

Ten patients were identified and included in the analysis (eTable). The mean age of the patients was 56 years (range, 39–76 years). Seven (70%) patients had skin of color (non-White) and 6 (60%) were female. The mean body mass index was 35 (range, 20–57), and 7 (70%) patients were clinically obese (body mass index >30). Only 2 (20%) patients had a history of a documented drug eruption (hives and erythema multiforme), and no patients had a history of FDE. Erythematous dusky patches followed by rapid development of blisters were noted within 3 days of drug initiation in 40% (4/10) and within 5 days in 80% (8/10) of patients. Antibiotics were identified as likely inciting agents in 8 (80%) patients. Biopsies were obtained in 3 (30%) patients and all 3 demonstrated cytotoxic CD8⁺ interface dermatitis with marked epithelial necrosis, neutrophilia, eosinophilia, and melanophage accumulation. Fever was present at initial presentation in only 4 (40%) patients, and only 1 (10%) patient had oral mucosal involvement. All 10 patients had intertriginous involvement (axillae, 90% [9/10]; gluteal cleft, 80% [8/10]; groin, 80% [8/10]; inframammary folds, 20% [2/10]), and there was considerable flank involvement in 9 (90%) patients. All 10 patients had initial erythematous to dusky, circular patches on the trunk and proximal extremities that then denuded most dramatically in the intertriginous areas (Figure). Six (60%) patients received systemic therapy, including 5 patients treated with a single dose of etanercept 50 mg. In patients with continued progression, 1 or 2 additional doses of etanercept 50 mg were administered at 48- to 72-hour intervals until blistering halted. Treatment with etanercept resulted in clinical improvement in all 5 patients, and there were no identifiable adverse events. The mean hospital stay was 19.7 days (range, 1–63 days).

This study highlights notable demographic and clinical features of GBFDE that have not been widely described in the literature. Large erythematous and dusky patches with broad zones of blistering with particular localization to the neck, intertriginous areas, and flanks typically are not described in SJS/TEN and may be helpful in distinguishing these conditions from GBFDE. Mild or complete lack of mucosal and facial involvement as well as more rapid time from drug initiation to rash (as rapid as 1 day) were key factors that aided in distinguishing GBFDE from SJS/TEN in our patients. Although a history of FDE is considered a key characteristic in the diagnosis of GBFDE, none of our patients had a known history of FDE, suggesting GBFDE may be the initial manifestation of FDE in some patients. Histopathology showed similar findings consistent with FDE in the 3 patients in whom a biopsy was performed. The remaining patients were diagnosed clinically based on the presence of distinctive, perfectly circular, dusky plaques present at the periphery of larger denuded areas, which are characteristic of GBFDE. Lower levels of serum granulysin³ have been shown to help distinguish GBFDE from SJS/TEN, but this test is not readily available with time-sensitive results at most institutions, and exact diagnostic ranges for GBFDE vs SJS/TEN are not yet known.

Our study was limited by a small number of patients at a single institution. Another limitation was the retrospective design.

Interestingly, a high proportion of our patients were non-White and clinically obese, which are factors that should be considered for future research. Sixty percent (6/10) of the patients in our study were Black, which is a notable difference from our hospital’s general admission demographics with Black individuals constituting 12% of patients.⁴ Our study also highlighted the utility of etanercept, which has reported mortality benefits and decreased time to re-epithelialization in other severe blistering cutaneous drug reactions including SJS/TEN,⁵ as a potential therapeutic option in GBFDE.

It is imperative that clinicians recognize the differences between GBFDE and SJS/TEN, as correct diagnosis is crucial for identifying the most likely causative drug as well as providing accurate prognostic information and may have future therapeutic implications as we further understand the immunologic profiles of these severe blistering drug reactions.

To the Editor:

Generalized bullous fixed drug eruption (GBFDE) is a rare subtype of fixed drug eruption (FDE) that manifests as widespread blisters and erosions following exposure to a causative drug.¹ Diagnostic criteria include involvement of at least 3 to 6 anatomic sites—head and neck, anterior trunk, posterior trunk, upper extremities, lower extremities, or genitalia—and more than 10% of the body surface area. It can be challenging to differentiate GBFDE from severe drug rashes such as Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) due to extensive body surface area involvement of blisters and erosions. Specific features distinguishing GBFDE from SJS/TEN include primary lesions consisting of larger erythematous to dusky, circular plaques that progress to bullae and coalesce into widespread erosions; history of FDE; lack of severe mucosal involvement; and better overall prognosis.² Treatment typically involves discontinuation of the culprit medication and supportive care; evidence for systemic therapies is not well established.

Our study aimed to characterize the clinical and demographic features of GBFDE in our institution to highlight potential key differences between this diagnosis and SJS/TEN. An electronic medical record search was performed to identify patients who were clinically diagnosed with GBFDE at New York-Presbyterian/Weill Cornell Medical Center (New York, New York) in both outpatient and inpatient settings from January 2015 to December 2022. This retrospective study was approved by the Weill Cornell Medicine institutional review board (#22-05024777).

Ten patients were identified and included in the analysis (eTable). The mean age of the patients was 56 years (range, 39–76 years). Seven (70%) patients had skin of color (non-White) and 6 (60%) were female. The mean body mass index was 35 (range, 20–57), and 7 (70%) patients were clinically obese (body mass index >30). Only 2 (20%) patients had a history of a documented drug eruption (hives and erythema multiforme), and no patients had a history of FDE. Erythematous dusky patches followed by rapid development of blisters were noted within 3 days of drug initiation in 40% (4/10) and within 5 days in 80% (8/10) of patients. Antibiotics were identified as likely inciting agents in 8 (80%) patients. Biopsies were obtained in 3 (30%) patients and all 3 demonstrated cytotoxic CD8⁺ interface dermatitis with marked epithelial necrosis, neutrophilia, eosinophilia, and melanophage accumulation. Fever was present at initial presentation in only 4 (40%) patients, and only 1 (10%) patient had oral mucosal involvement. All 10 patients had intertriginous involvement (axillae, 90% [9/10]; gluteal cleft, 80% [8/10]; groin, 80% [8/10]; inframammary folds, 20% [2/10]), and there was considerable flank involvement in 9 (90%) patients. All 10 patients had initial erythematous to dusky, circular patches on the trunk and proximal extremities that then denuded most dramatically in the intertriginous areas (Figure). Six (60%) patients received systemic therapy, including 5 patients treated with a single dose of etanercept 50 mg. In patients with continued progression, 1 or 2 additional doses of etanercept 50 mg were administered at 48- to 72-hour intervals until blistering halted. Treatment with etanercept resulted in clinical improvement in all 5 patients, and there were no identifiable adverse events. The mean hospital stay was 19.7 days (range, 1–63 days).

This study highlights notable demographic and clinical features of GBFDE that have not been widely described in the literature. Large erythematous and dusky patches with broad zones of blistering with particular localization to the neck, intertriginous areas, and flanks typically are not described in SJS/TEN and may be helpful in distinguishing these conditions from GBFDE. Mild or complete lack of mucosal and facial involvement as well as more rapid time from drug initiation to rash (as rapid as 1 day) were key factors that aided in distinguishing GBFDE from SJS/TEN in our patients. Although a history of FDE is considered a key characteristic in the diagnosis of GBFDE, none of our patients had a known history of FDE, suggesting GBFDE may be the initial manifestation of FDE in some patients. Histopathology showed similar findings consistent with FDE in the 3 patients in whom a biopsy was performed. The remaining patients were diagnosed clinically based on the presence of distinctive, perfectly circular, dusky plaques present at the periphery of larger denuded areas, which are characteristic of GBFDE. Lower levels of serum granulysin³ have been shown to help distinguish GBFDE from SJS/TEN, but this test is not readily available with time-sensitive results at most institutions, and exact diagnostic ranges for GBFDE vs SJS/TEN are not yet known.

Our study was limited by a small number of patients at a single institution. Another limitation was the retrospective design.

Interestingly, a high proportion of our patients were non-White and clinically obese, which are factors that should be considered for future research. Sixty percent (6/10) of the patients in our study were Black, which is a notable difference from our hospital’s general admission demographics with Black individuals constituting 12% of patients.⁴ Our study also highlighted the utility of etanercept, which has reported mortality benefits and decreased time to re-epithelialization in other severe blistering cutaneous drug reactions including SJS/TEN,⁵ as a potential therapeutic option in GBFDE.

It is imperative that clinicians recognize the differences between GBFDE and SJS/TEN, as correct diagnosis is crucial for identifying the most likely causative drug as well as providing accurate prognostic information and may have future therapeutic implications as we further understand the immunologic profiles of these severe blistering drug reactions.