Cutis

The Diagnosis: Nodular Basal Cell Carcinoma

Histopathology of the lesion showed a large basaloid lobule with focal epidermal attachment, peripheral nuclear palisading with cleft formation between the tumor and surrounding stroma, fibromyxoid stroma and mild pleomorphism, and variable mitotic activity and apoptosis (Figure). Based on the clinical presentation and histopathology, the patient was diagnosed with nodular basal cell carcinoma (BCC). He underwent a wide local excision of the affected area that was repaired with a splitthickness skin graft.

Basal cell carcinoma is the most common skin cancer worldwide and typically occurs due to years of UV radiation damage on sun-exposed skin, which accounts for a higher frequency of BCC occurring in patients residing in geographic locations with greater UV exposure (eg, higher and lower latitudes). In addition to cumulative UV dose, the duration of the exposure as well as its intensity also play a role in the development of BCC, particularly in early childhood and adolescence. Nevertheless, UV exposure is not the only risk factor, as 20% of BCCs arise in skin that is not exposed to the sun. Other risk factors include exposure to ionizing radiation and arsenic, immunosuppression, and genetic predisposition.¹ Although these malignancies typically do not metastasize, growth can lead to local tissue destruction and major disfigurement if not treated in a timely fashion.²

In our patient, the differential diagnosis included pyoderma gangrenosum (PG) given the clinical appearance of the cribriform base and violaceous undermined rim of the ulcer. Pyoderma gangrenosum is a rare neutrophilic disorder that often results in ulcers that have been associated with various systemic autoimmune and inflammatory conditions, such as inflammatory bowel disease. There are 4 main subtypes of PG: the classic ulcerative type (our patient); the pustular type, which most often is seen in patients with inflammatory bowel disease; the bullous type, which can be seen in patients with an associated lymphoproliferative disorder; and the vegetative type. It frequently is thought of as both a clinical and histologic diagnosis of exclusion due to the nonspecific histopathologic features; most lesions demonstrate an infiltrate of neutrophils in the dermis. A biopsy was crucial in our patient, considering that diagnosis and treatment would have been further delayed had the patient been empirically treated with oral and topical steroids for presumed PG, which is precisely why PG is a diagnosis of exclusion. It is imperative for clinicians to rule out other pathologies, such as infection or malignancy, as demonstrated in our patient. The progressive onset and slow evolution of the lesion over years along with a lack of pain were more suggestive of BCC rather than PG. However, there is a report in the literature of PG mimicking BCC with both clinical and dermoscopic findings.³

Venous or stasis ulcers are painless, and although they rarely occur on the calf, they typically are seen lower on the leg such as on the medial ankles. Our patient endorsed occasional swelling of the affected leg and presented with edema, but overlying stasis change and other signs of venous insufficiency were absent.

Buruli ulcer is a painless chronic debilitating cutaneous disease resulting in indolent necrotizing skin as well as subcutaneous and bone lesions. It is caused by the environmental organism Mycobacterium ulcerans and typically is reported in Africa, Central/South America, the Western Pacific Region, and Australia.⁴ Histopathology usually demonstrates necrosis of subcutaneous tissue and dermal collagen accompanied by inflammation and acidfast bacilli highlighted by Ziehl-Neelsen stain.⁵ Smears of the lesions as well as culture and polymerase chain reaction for acid-fast bacilli also can be performed. Our patient reported no recent travel to any endemic areas and had no other risk factors or exposures to the pathogen responsible for this condition.

Traumatic ulcer also was included in the differential diagnosis, but the patient denied preceding trauma to the area, and the contralateral foot prosthesis did not rub on or impact the affected leg.

Basal cell carcinoma typically is treated surgically, but choice of treatment can depend on the subtype, size, tumor site, and/or patient preference.¹ Other treatment modalities include electrodesiccation and curettage, cryosurgical destruction, photodynamic therapy, radiation, topical therapies, and systemic medications. Radiotherapy can be considered as a primary treatment option for BCC if surgery is contraindicated or declined by the patient, but it also is useful as an adjuvant therapy when there is perineural invasion of the tumor or positive margins. Hedgehog pathway inhibitors such as vismodegib currently are indicated for patients who are not candidates for surgery or radiation as well as for those with metastatic or locally advanced, recurrent BCC. There is no single treatment method ideal for every lesion or patient. Specific populations such as the elderly, the immunosuppressed, or those with poor baseline functional status may warrant a nonsurgical approach. The clinician must take into consideration all factors while at the same time thinking about how to best accomplish the goals of recurrencefree tumor removal, correction of any underlying functional impairment from the tumor, and maintenance of cosmesis.¹

The Diagnosis: Nodular Basal Cell Carcinoma

Histopathology of the lesion showed a large basaloid lobule with focal epidermal attachment, peripheral nuclear palisading with cleft formation between the tumor and surrounding stroma, fibromyxoid stroma and mild pleomorphism, and variable mitotic activity and apoptosis (Figure). Based on the clinical presentation and histopathology, the patient was diagnosed with nodular basal cell carcinoma (BCC). He underwent a wide local excision of the affected area that was repaired with a splitthickness skin graft.

Basal cell carcinoma is the most common skin cancer worldwide and typically occurs due to years of UV radiation damage on sun-exposed skin, which accounts for a higher frequency of BCC occurring in patients residing in geographic locations with greater UV exposure (eg, higher and lower latitudes). In addition to cumulative UV dose, the duration of the exposure as well as its intensity also play a role in the development of BCC, particularly in early childhood and adolescence. Nevertheless, UV exposure is not the only risk factor, as 20% of BCCs arise in skin that is not exposed to the sun. Other risk factors include exposure to ionizing radiation and arsenic, immunosuppression, and genetic predisposition.¹ Although these malignancies typically do not metastasize, growth can lead to local tissue destruction and major disfigurement if not treated in a timely fashion.²

In our patient, the differential diagnosis included pyoderma gangrenosum (PG) given the clinical appearance of the cribriform base and violaceous undermined rim of the ulcer. Pyoderma gangrenosum is a rare neutrophilic disorder that often results in ulcers that have been associated with various systemic autoimmune and inflammatory conditions, such as inflammatory bowel disease. There are 4 main subtypes of PG: the classic ulcerative type (our patient); the pustular type, which most often is seen in patients with inflammatory bowel disease; the bullous type, which can be seen in patients with an associated lymphoproliferative disorder; and the vegetative type. It frequently is thought of as both a clinical and histologic diagnosis of exclusion due to the nonspecific histopathologic features; most lesions demonstrate an infiltrate of neutrophils in the dermis. A biopsy was crucial in our patient, considering that diagnosis and treatment would have been further delayed had the patient been empirically treated with oral and topical steroids for presumed PG, which is precisely why PG is a diagnosis of exclusion. It is imperative for clinicians to rule out other pathologies, such as infection or malignancy, as demonstrated in our patient. The progressive onset and slow evolution of the lesion over years along with a lack of pain were more suggestive of BCC rather than PG. However, there is a report in the literature of PG mimicking BCC with both clinical and dermoscopic findings.³

Venous or stasis ulcers are painless, and although they rarely occur on the calf, they typically are seen lower on the leg such as on the medial ankles. Our patient endorsed occasional swelling of the affected leg and presented with edema, but overlying stasis change and other signs of venous insufficiency were absent.

Buruli ulcer is a painless chronic debilitating cutaneous disease resulting in indolent necrotizing skin as well as subcutaneous and bone lesions. It is caused by the environmental organism Mycobacterium ulcerans and typically is reported in Africa, Central/South America, the Western Pacific Region, and Australia.⁴ Histopathology usually demonstrates necrosis of subcutaneous tissue and dermal collagen accompanied by inflammation and acidfast bacilli highlighted by Ziehl-Neelsen stain.⁵ Smears of the lesions as well as culture and polymerase chain reaction for acid-fast bacilli also can be performed. Our patient reported no recent travel to any endemic areas and had no other risk factors or exposures to the pathogen responsible for this condition.

Traumatic ulcer also was included in the differential diagnosis, but the patient denied preceding trauma to the area, and the contralateral foot prosthesis did not rub on or impact the affected leg.

Basal cell carcinoma typically is treated surgically, but choice of treatment can depend on the subtype, size, tumor site, and/or patient preference.¹ Other treatment modalities include electrodesiccation and curettage, cryosurgical destruction, photodynamic therapy, radiation, topical therapies, and systemic medications. Radiotherapy can be considered as a primary treatment option for BCC if surgery is contraindicated or declined by the patient, but it also is useful as an adjuvant therapy when there is perineural invasion of the tumor or positive margins. Hedgehog pathway inhibitors such as vismodegib currently are indicated for patients who are not candidates for surgery or radiation as well as for those with metastatic or locally advanced, recurrent BCC. There is no single treatment method ideal for every lesion or patient. Specific populations such as the elderly, the immunosuppressed, or those with poor baseline functional status may warrant a nonsurgical approach. The clinician must take into consideration all factors while at the same time thinking about how to best accomplish the goals of recurrencefree tumor removal, correction of any underlying functional impairment from the tumor, and maintenance of cosmesis.¹

The Diagnosis: Nodular Basal Cell Carcinoma

Histopathology of the lesion showed a large basaloid lobule with focal epidermal attachment, peripheral nuclear palisading with cleft formation between the tumor and surrounding stroma, fibromyxoid stroma and mild pleomorphism, and variable mitotic activity and apoptosis (Figure). Based on the clinical presentation and histopathology, the patient was diagnosed with nodular basal cell carcinoma (BCC). He underwent a wide local excision of the affected area that was repaired with a splitthickness skin graft.

Basal cell carcinoma is the most common skin cancer worldwide and typically occurs due to years of UV radiation damage on sun-exposed skin, which accounts for a higher frequency of BCC occurring in patients residing in geographic locations with greater UV exposure (eg, higher and lower latitudes). In addition to cumulative UV dose, the duration of the exposure as well as its intensity also play a role in the development of BCC, particularly in early childhood and adolescence. Nevertheless, UV exposure is not the only risk factor, as 20% of BCCs arise in skin that is not exposed to the sun. Other risk factors include exposure to ionizing radiation and arsenic, immunosuppression, and genetic predisposition.¹ Although these malignancies typically do not metastasize, growth can lead to local tissue destruction and major disfigurement if not treated in a timely fashion.²

In our patient, the differential diagnosis included pyoderma gangrenosum (PG) given the clinical appearance of the cribriform base and violaceous undermined rim of the ulcer. Pyoderma gangrenosum is a rare neutrophilic disorder that often results in ulcers that have been associated with various systemic autoimmune and inflammatory conditions, such as inflammatory bowel disease. There are 4 main subtypes of PG: the classic ulcerative type (our patient); the pustular type, which most often is seen in patients with inflammatory bowel disease; the bullous type, which can be seen in patients with an associated lymphoproliferative disorder; and the vegetative type. It frequently is thought of as both a clinical and histologic diagnosis of exclusion due to the nonspecific histopathologic features; most lesions demonstrate an infiltrate of neutrophils in the dermis. A biopsy was crucial in our patient, considering that diagnosis and treatment would have been further delayed had the patient been empirically treated with oral and topical steroids for presumed PG, which is precisely why PG is a diagnosis of exclusion. It is imperative for clinicians to rule out other pathologies, such as infection or malignancy, as demonstrated in our patient. The progressive onset and slow evolution of the lesion over years along with a lack of pain were more suggestive of BCC rather than PG. However, there is a report in the literature of PG mimicking BCC with both clinical and dermoscopic findings.³

Venous or stasis ulcers are painless, and although they rarely occur on the calf, they typically are seen lower on the leg such as on the medial ankles. Our patient endorsed occasional swelling of the affected leg and presented with edema, but overlying stasis change and other signs of venous insufficiency were absent.

Buruli ulcer is a painless chronic debilitating cutaneous disease resulting in indolent necrotizing skin as well as subcutaneous and bone lesions. It is caused by the environmental organism Mycobacterium ulcerans and typically is reported in Africa, Central/South America, the Western Pacific Region, and Australia.⁴ Histopathology usually demonstrates necrosis of subcutaneous tissue and dermal collagen accompanied by inflammation and acidfast bacilli highlighted by Ziehl-Neelsen stain.⁵ Smears of the lesions as well as culture and polymerase chain reaction for acid-fast bacilli also can be performed. Our patient reported no recent travel to any endemic areas and had no other risk factors or exposures to the pathogen responsible for this condition.

Traumatic ulcer also was included in the differential diagnosis, but the patient denied preceding trauma to the area, and the contralateral foot prosthesis did not rub on or impact the affected leg.

Basal cell carcinoma typically is treated surgically, but choice of treatment can depend on the subtype, size, tumor site, and/or patient preference.¹ Other treatment modalities include electrodesiccation and curettage, cryosurgical destruction, photodynamic therapy, radiation, topical therapies, and systemic medications. Radiotherapy can be considered as a primary treatment option for BCC if surgery is contraindicated or declined by the patient, but it also is useful as an adjuvant therapy when there is perineural invasion of the tumor or positive margins. Hedgehog pathway inhibitors such as vismodegib currently are indicated for patients who are not candidates for surgery or radiation as well as for those with metastatic or locally advanced, recurrent BCC. There is no single treatment method ideal for every lesion or patient. Specific populations such as the elderly, the immunosuppressed, or those with poor baseline functional status may warrant a nonsurgical approach. The clinician must take into consideration all factors while at the same time thinking about how to best accomplish the goals of recurrencefree tumor removal, correction of any underlying functional impairment from the tumor, and maintenance of cosmesis.¹

To the Editor:

A 42-year man presented with hollowing of the upper eyelid and skin discoloration of the left periorbital area of 10 years’ duration. He was a professional mixed martial arts fighter with a history of 2 surgeries for retinal detachment of the left eye 13 years prior to the current presentation. The patient also has macular scarring in the left eye. He denied a history of facial fracture, reconstructive surgery, or other medical conditions. His visual acuity was unknown; however, he did not require corrective glasses. He used 3 prescription ophthalmic eye drops—dorzolamide hydrochloride plus timolol maleate, 10 mL; brimonidine tartrate ophthalmic solution 0.15%, 5 mL; and latanoprost ophthalmic solution 0.005%, 125 μg/2.5 mL—in the left eye to lower intraocular pressure, as therapy for glaucoma. If left untreated, glaucoma can lead to vision loss.

Physical examination revealed periorbital hyperpigmentation on the left side; hypertrichosis and eyelash trichomegaly compared to the right side; and a deep left upper orbital sulcus compared to the right side (Figure). The patient was alert and oriented to person, place, and time. Extraocular movement was intact bilaterally, and his pupillary reflex was symmetric. No tenderness was noted over the affected area on palpation; no subcutaneous masses or lesions were observed or palpated. There was no ocular discharge, the conjunctiva was pink, and the sclera was white bilaterally.

The differential diagnosis included professional trauma-induced orbital changes, nevus of Ota (oculomucodermal melanocytosis), prostaglandin-associated periorbitopathy (PAP), and melasma. Although the patient sustained an injury that caused retinal detachment, he never experienced an orbital bone fracture; additionally, a fracture would not explain the skin discoloration or longer eyelashes. Periorbital nevus of Ota most commonly manifests as a unilateral scleral and brown-bluish skin discoloration but does not cause hollowing of the orbital sulcus or affect the length and thickness of eyelashes. Melasma—bilateral skin hyperpigmentation that most commonly affects women—can be induced by oral contraceptives, antibiotics, heat, sun exposure, and pregnancy. It does not affect the color of the iris or the depth of the scleral sulcus, and it does not increase the length and thickness of eyelashes. Based on the clinical presentation and a review of the eye drops used, he was diagnosed with PAP due to prolonged use of latanoprost ophthalmic solution. The patient was referred to an ophthalmologist for consideration of a switch to a different class of medication.

Of the 3 eye drops used by this patient, latanoprost, a prostaglandin analog, decreases intraocular pressure and is known to cause PAP. This condition comprises a constellation of changes, including upper eyelid ptosis, deepening of the upper eyelid sulcus, involution of dermatochalasis, periorbital fat atrophy, mild enophthalmos (sunken eye), inferior scleral show, increased prominence of eyelid vessels, and tight eyelids.¹ Latanoprost most often produces these findings, but all prostaglandin ophthalmic medications can, including the dual-indication bimatoprost, which was approved by the US Food and Drug Administration to reduce elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension but also is used to grow darker, thicker, and longer eyelashes. Clinicians who prescribe bimatoprost for this cosmetic indication should be mindful of the potential for PAP and discuss it with patients.

The prescribing information (PI) for bimatoprost (Latisse; Allergan) does not list PAP as an adverse reaction observed in the 4-month multicenter, double-blind, randomized, vehicle-controlled study of bimatoprost (as Latisse) in 278 adults.² The PI does list “periorbital and lid changes associated with periorbital fat atrophy and skin tightness resulting in deepening of eyelid sulcus and eyelid ptosis” as an adverse reaction in postmarketing experience. However, according to the PI, the frequency of these adverse reactions cannot be established, as the reporting of such incidents was voluntary and the size of the treated population was uncertain.²

Prostaglandins can cause periorbitopathy by several mechanisms; one speculated cause is that this group of medications might provoke smooth muscle contraction. Prostaglandin medications also have an affinity for fat cells¹; atrophy of fat cells can lead to enophthalmos and deepening upper eyelid sulcus. In an observational study of 105 participants who were using a prostaglandin in 1 eye for longer than 1 month (the other eye was used as a control), the overall frequency of prostaglandin-associated periorbitopathy was 93.3% in the bimatoprost group, 41.4% in the latanoprost group, and 70% in the travoprost group, while the frequency of deepening of the upper eyelid sulcus was 80% in the bimatoprost group, 15.7% in the latanoprost group, and 45% in the travoprost group.³ These changes may not be as striking when a patient is using a prostaglandin ophthalmic medication in both eyes and may not be noticed even by the patient. It is prudent for the clinician to take a baseline photograph of the patient when these medications are prescribed to observe for early signs of periorbitopathy. These adverse effects may not be reversible when the medication is discontinued⁴ and have been observed as early as 4 to 6 weeks after the start of treatment.⁵

Our patient was counseled that his constellation of PAP findings potentially could be partially reversed over months or even a year or longer if the offending agent was discontinued. However, he was cautioned that cessation of latanoprost first needed to be discussed with his ophthalmologist, who would determine if there was a suitable alternative to a prostaglandin analog for him. The patient’s only concern was the aesthetic appearance of the left periorbital area. A hyaluronic acid filler or fat grafting can be considered for correction of orbital sulcus hollowing; however, we could not locate any long-term studies in which such corrective treatments were applied for PAP. Our patient continues to use latanoprost with no change in the frequency of use. There have been no further changes or progression in the physical appearance of the left eye or periorbital area. The patient has not undergone any corrective treatments.

To the Editor:

A 42-year man presented with hollowing of the upper eyelid and skin discoloration of the left periorbital area of 10 years’ duration. He was a professional mixed martial arts fighter with a history of 2 surgeries for retinal detachment of the left eye 13 years prior to the current presentation. The patient also has macular scarring in the left eye. He denied a history of facial fracture, reconstructive surgery, or other medical conditions. His visual acuity was unknown; however, he did not require corrective glasses. He used 3 prescription ophthalmic eye drops—dorzolamide hydrochloride plus timolol maleate, 10 mL; brimonidine tartrate ophthalmic solution 0.15%, 5 mL; and latanoprost ophthalmic solution 0.005%, 125 μg/2.5 mL—in the left eye to lower intraocular pressure, as therapy for glaucoma. If left untreated, glaucoma can lead to vision loss.

Physical examination revealed periorbital hyperpigmentation on the left side; hypertrichosis and eyelash trichomegaly compared to the right side; and a deep left upper orbital sulcus compared to the right side (Figure). The patient was alert and oriented to person, place, and time. Extraocular movement was intact bilaterally, and his pupillary reflex was symmetric. No tenderness was noted over the affected area on palpation; no subcutaneous masses or lesions were observed or palpated. There was no ocular discharge, the conjunctiva was pink, and the sclera was white bilaterally.

The differential diagnosis included professional trauma-induced orbital changes, nevus of Ota (oculomucodermal melanocytosis), prostaglandin-associated periorbitopathy (PAP), and melasma. Although the patient sustained an injury that caused retinal detachment, he never experienced an orbital bone fracture; additionally, a fracture would not explain the skin discoloration or longer eyelashes. Periorbital nevus of Ota most commonly manifests as a unilateral scleral and brown-bluish skin discoloration but does not cause hollowing of the orbital sulcus or affect the length and thickness of eyelashes. Melasma—bilateral skin hyperpigmentation that most commonly affects women—can be induced by oral contraceptives, antibiotics, heat, sun exposure, and pregnancy. It does not affect the color of the iris or the depth of the scleral sulcus, and it does not increase the length and thickness of eyelashes. Based on the clinical presentation and a review of the eye drops used, he was diagnosed with PAP due to prolonged use of latanoprost ophthalmic solution. The patient was referred to an ophthalmologist for consideration of a switch to a different class of medication.

Of the 3 eye drops used by this patient, latanoprost, a prostaglandin analog, decreases intraocular pressure and is known to cause PAP. This condition comprises a constellation of changes, including upper eyelid ptosis, deepening of the upper eyelid sulcus, involution of dermatochalasis, periorbital fat atrophy, mild enophthalmos (sunken eye), inferior scleral show, increased prominence of eyelid vessels, and tight eyelids.¹ Latanoprost most often produces these findings, but all prostaglandin ophthalmic medications can, including the dual-indication bimatoprost, which was approved by the US Food and Drug Administration to reduce elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension but also is used to grow darker, thicker, and longer eyelashes. Clinicians who prescribe bimatoprost for this cosmetic indication should be mindful of the potential for PAP and discuss it with patients.

The prescribing information (PI) for bimatoprost (Latisse; Allergan) does not list PAP as an adverse reaction observed in the 4-month multicenter, double-blind, randomized, vehicle-controlled study of bimatoprost (as Latisse) in 278 adults.² The PI does list “periorbital and lid changes associated with periorbital fat atrophy and skin tightness resulting in deepening of eyelid sulcus and eyelid ptosis” as an adverse reaction in postmarketing experience. However, according to the PI, the frequency of these adverse reactions cannot be established, as the reporting of such incidents was voluntary and the size of the treated population was uncertain.²

Prostaglandins can cause periorbitopathy by several mechanisms; one speculated cause is that this group of medications might provoke smooth muscle contraction. Prostaglandin medications also have an affinity for fat cells¹; atrophy of fat cells can lead to enophthalmos and deepening upper eyelid sulcus. In an observational study of 105 participants who were using a prostaglandin in 1 eye for longer than 1 month (the other eye was used as a control), the overall frequency of prostaglandin-associated periorbitopathy was 93.3% in the bimatoprost group, 41.4% in the latanoprost group, and 70% in the travoprost group, while the frequency of deepening of the upper eyelid sulcus was 80% in the bimatoprost group, 15.7% in the latanoprost group, and 45% in the travoprost group.³ These changes may not be as striking when a patient is using a prostaglandin ophthalmic medication in both eyes and may not be noticed even by the patient. It is prudent for the clinician to take a baseline photograph of the patient when these medications are prescribed to observe for early signs of periorbitopathy. These adverse effects may not be reversible when the medication is discontinued⁴ and have been observed as early as 4 to 6 weeks after the start of treatment.⁵

Our patient was counseled that his constellation of PAP findings potentially could be partially reversed over months or even a year or longer if the offending agent was discontinued. However, he was cautioned that cessation of latanoprost first needed to be discussed with his ophthalmologist, who would determine if there was a suitable alternative to a prostaglandin analog for him. The patient’s only concern was the aesthetic appearance of the left periorbital area. A hyaluronic acid filler or fat grafting can be considered for correction of orbital sulcus hollowing; however, we could not locate any long-term studies in which such corrective treatments were applied for PAP. Our patient continues to use latanoprost with no change in the frequency of use. There have been no further changes or progression in the physical appearance of the left eye or periorbital area. The patient has not undergone any corrective treatments.

To the Editor:

A 42-year man presented with hollowing of the upper eyelid and skin discoloration of the left periorbital area of 10 years’ duration. He was a professional mixed martial arts fighter with a history of 2 surgeries for retinal detachment of the left eye 13 years prior to the current presentation. The patient also has macular scarring in the left eye. He denied a history of facial fracture, reconstructive surgery, or other medical conditions. His visual acuity was unknown; however, he did not require corrective glasses. He used 3 prescription ophthalmic eye drops—dorzolamide hydrochloride plus timolol maleate, 10 mL; brimonidine tartrate ophthalmic solution 0.15%, 5 mL; and latanoprost ophthalmic solution 0.005%, 125 μg/2.5 mL—in the left eye to lower intraocular pressure, as therapy for glaucoma. If left untreated, glaucoma can lead to vision loss.

Physical examination revealed periorbital hyperpigmentation on the left side; hypertrichosis and eyelash trichomegaly compared to the right side; and a deep left upper orbital sulcus compared to the right side (Figure). The patient was alert and oriented to person, place, and time. Extraocular movement was intact bilaterally, and his pupillary reflex was symmetric. No tenderness was noted over the affected area on palpation; no subcutaneous masses or lesions were observed or palpated. There was no ocular discharge, the conjunctiva was pink, and the sclera was white bilaterally.

The differential diagnosis included professional trauma-induced orbital changes, nevus of Ota (oculomucodermal melanocytosis), prostaglandin-associated periorbitopathy (PAP), and melasma. Although the patient sustained an injury that caused retinal detachment, he never experienced an orbital bone fracture; additionally, a fracture would not explain the skin discoloration or longer eyelashes. Periorbital nevus of Ota most commonly manifests as a unilateral scleral and brown-bluish skin discoloration but does not cause hollowing of the orbital sulcus or affect the length and thickness of eyelashes. Melasma—bilateral skin hyperpigmentation that most commonly affects women—can be induced by oral contraceptives, antibiotics, heat, sun exposure, and pregnancy. It does not affect the color of the iris or the depth of the scleral sulcus, and it does not increase the length and thickness of eyelashes. Based on the clinical presentation and a review of the eye drops used, he was diagnosed with PAP due to prolonged use of latanoprost ophthalmic solution. The patient was referred to an ophthalmologist for consideration of a switch to a different class of medication.

Of the 3 eye drops used by this patient, latanoprost, a prostaglandin analog, decreases intraocular pressure and is known to cause PAP. This condition comprises a constellation of changes, including upper eyelid ptosis, deepening of the upper eyelid sulcus, involution of dermatochalasis, periorbital fat atrophy, mild enophthalmos (sunken eye), inferior scleral show, increased prominence of eyelid vessels, and tight eyelids.¹ Latanoprost most often produces these findings, but all prostaglandin ophthalmic medications can, including the dual-indication bimatoprost, which was approved by the US Food and Drug Administration to reduce elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension but also is used to grow darker, thicker, and longer eyelashes. Clinicians who prescribe bimatoprost for this cosmetic indication should be mindful of the potential for PAP and discuss it with patients.

The prescribing information (PI) for bimatoprost (Latisse; Allergan) does not list PAP as an adverse reaction observed in the 4-month multicenter, double-blind, randomized, vehicle-controlled study of bimatoprost (as Latisse) in 278 adults.² The PI does list “periorbital and lid changes associated with periorbital fat atrophy and skin tightness resulting in deepening of eyelid sulcus and eyelid ptosis” as an adverse reaction in postmarketing experience. However, according to the PI, the frequency of these adverse reactions cannot be established, as the reporting of such incidents was voluntary and the size of the treated population was uncertain.²

Prostaglandins can cause periorbitopathy by several mechanisms; one speculated cause is that this group of medications might provoke smooth muscle contraction. Prostaglandin medications also have an affinity for fat cells¹; atrophy of fat cells can lead to enophthalmos and deepening upper eyelid sulcus. In an observational study of 105 participants who were using a prostaglandin in 1 eye for longer than 1 month (the other eye was used as a control), the overall frequency of prostaglandin-associated periorbitopathy was 93.3% in the bimatoprost group, 41.4% in the latanoprost group, and 70% in the travoprost group, while the frequency of deepening of the upper eyelid sulcus was 80% in the bimatoprost group, 15.7% in the latanoprost group, and 45% in the travoprost group.³ These changes may not be as striking when a patient is using a prostaglandin ophthalmic medication in both eyes and may not be noticed even by the patient. It is prudent for the clinician to take a baseline photograph of the patient when these medications are prescribed to observe for early signs of periorbitopathy. These adverse effects may not be reversible when the medication is discontinued⁴ and have been observed as early as 4 to 6 weeks after the start of treatment.⁵

Our patient was counseled that his constellation of PAP findings potentially could be partially reversed over months or even a year or longer if the offending agent was discontinued. However, he was cautioned that cessation of latanoprost first needed to be discussed with his ophthalmologist, who would determine if there was a suitable alternative to a prostaglandin analog for him. The patient’s only concern was the aesthetic appearance of the left periorbital area. A hyaluronic acid filler or fat grafting can be considered for correction of orbital sulcus hollowing; however, we could not locate any long-term studies in which such corrective treatments were applied for PAP. Our patient continues to use latanoprost with no change in the frequency of use. There have been no further changes or progression in the physical appearance of the left eye or periorbital area. The patient has not undergone any corrective treatments.

To the Editor:

Vitiligo is a depigmentation disorder that results from the loss of melanocytes in the epidermis.¹ The most widely accepted pathophysiology for melanocyte destruction in vitiligo is an autoimmune process involving dysregulated cytokine production and autoreactive T-cell activation.¹ Individuals with cutaneous autoinflammatory conditions currently are vital patient populations warranting research, as their susceptibility to COVID-19 infection may differ from the general population. We previously found a small increased risk for COVID-19 infection in patients with psoriasis,² which suggests that other dermatologic conditions also may impact COVID-19 risk. The risk for COVID-19 infection in patients with vitiligo remains largely unknown. In this retrospective cohort study, we investigated the risk for COVID-19 infection in patients with vitiligo compared with those without vitiligo utilizing claims data from the COVID-19 Research Database (https://covid19researchdatabase.org/).

Claims were evaluated for patients aged 3 years and older with a vitiligo diagnosis (International Classification of Diseases, Tenth Revision [ICD-10] code L80) that was made between January 1, 2016, and January 1, 2020. Individuals without a vitiligo diagnosis during the same period were placed (4:1 ratio) in the control group and were matched with study group patients for age and sex. All comorbidity variables and vitiligo diagnoses were extracted from ICD-10 codes that were given prior to a diagnosis of COVID-19. We then constructed multivariable logistic regression models adjusting for measured confounders to evaluate if vitiligo was associated with higher risk for COVID-19 infection after January 1, 2020.

The vitiligo and nonvitiligo cohorts included 40,363 and 161,452 patients, respectively (Table 1). Logistic regression analysis with adjustment for confounding variables, including high comorbid risk factors (Table 2) revealed that patients with a diagnosis of vitiligo had significantly increased odds of COVID-19 infection compared with patients without vitiligo (adjusted odds ratio [AOR], 1.47; 95% CI, 1.37-1.57; P<.001)(Table 3). Additionally, subgroup logistic analyses for sex, age, and exclusion of patients who were HIV positive revealed that females with vitiligo had higher odds of contracting COVID-19 than males with vitiligo (Table 3).

Our results showed that patients with vitiligo had a higher relative risk for contracting COVID-19 than individuals without vitiligo. It has been reported that the prevalence of COVID-19 is higher among patients with autoimmune diseases compared to the general population.³ Additionally, a handful of vitiligo patients are managed with immunosuppressive agents that may further weaken their immune response.¹ Moreover, survey results from dermatologists managing vitiligo patients revealed that physicians were fairly comfortable prescribing immunosuppressants and encouraging in-office phototherapy during the COVID-19 pandemic.⁴ As a result, more patients may have been attending in-office visits for their phototherapy, which may have increased their risk for COVID-19. Although these factors play a role in ­COVID-19 infection rates, the underlying immune dysregulation in vitiligo in relation to COVID-19 remains unknown and should be further explored.

Our findings are limited by the use of ICD-10 codes, the inability to control for all potential confounding variables, the lack of data regarding the stage of vitiligo, and the absence of data for undiagnosed COVID-19 infections. In addition, patients with vitiligo may be more likely to seek care, potentially increasing their rates of COVID-19 testing. The inability to identify the stage of vitiligo during enrollment in the database may have altered our results, as individuals with active disease have increased levels of IFN-γ. Increased secretion of IFN-γ also potentially helps in the clearance of COVID-19 infection.¹ Future studies should investigate this relationship via planned ­COVID-19 testing, identification of vitiligo stage, and controlling for other associated comorbidities.

To the Editor:

Vitiligo is a depigmentation disorder that results from the loss of melanocytes in the epidermis.¹ The most widely accepted pathophysiology for melanocyte destruction in vitiligo is an autoimmune process involving dysregulated cytokine production and autoreactive T-cell activation.¹ Individuals with cutaneous autoinflammatory conditions currently are vital patient populations warranting research, as their susceptibility to COVID-19 infection may differ from the general population. We previously found a small increased risk for COVID-19 infection in patients with psoriasis,² which suggests that other dermatologic conditions also may impact COVID-19 risk. The risk for COVID-19 infection in patients with vitiligo remains largely unknown. In this retrospective cohort study, we investigated the risk for COVID-19 infection in patients with vitiligo compared with those without vitiligo utilizing claims data from the COVID-19 Research Database (https://covid19researchdatabase.org/).

Claims were evaluated for patients aged 3 years and older with a vitiligo diagnosis (International Classification of Diseases, Tenth Revision [ICD-10] code L80) that was made between January 1, 2016, and January 1, 2020. Individuals without a vitiligo diagnosis during the same period were placed (4:1 ratio) in the control group and were matched with study group patients for age and sex. All comorbidity variables and vitiligo diagnoses were extracted from ICD-10 codes that were given prior to a diagnosis of COVID-19. We then constructed multivariable logistic regression models adjusting for measured confounders to evaluate if vitiligo was associated with higher risk for COVID-19 infection after January 1, 2020.

The vitiligo and nonvitiligo cohorts included 40,363 and 161,452 patients, respectively (Table 1). Logistic regression analysis with adjustment for confounding variables, including high comorbid risk factors (Table 2) revealed that patients with a diagnosis of vitiligo had significantly increased odds of COVID-19 infection compared with patients without vitiligo (adjusted odds ratio [AOR], 1.47; 95% CI, 1.37-1.57; P<.001)(Table 3). Additionally, subgroup logistic analyses for sex, age, and exclusion of patients who were HIV positive revealed that females with vitiligo had higher odds of contracting COVID-19 than males with vitiligo (Table 3).

Our results showed that patients with vitiligo had a higher relative risk for contracting COVID-19 than individuals without vitiligo. It has been reported that the prevalence of COVID-19 is higher among patients with autoimmune diseases compared to the general population.³ Additionally, a handful of vitiligo patients are managed with immunosuppressive agents that may further weaken their immune response.¹ Moreover, survey results from dermatologists managing vitiligo patients revealed that physicians were fairly comfortable prescribing immunosuppressants and encouraging in-office phototherapy during the COVID-19 pandemic.⁴ As a result, more patients may have been attending in-office visits for their phototherapy, which may have increased their risk for COVID-19. Although these factors play a role in ­COVID-19 infection rates, the underlying immune dysregulation in vitiligo in relation to COVID-19 remains unknown and should be further explored.

Our findings are limited by the use of ICD-10 codes, the inability to control for all potential confounding variables, the lack of data regarding the stage of vitiligo, and the absence of data for undiagnosed COVID-19 infections. In addition, patients with vitiligo may be more likely to seek care, potentially increasing their rates of COVID-19 testing. The inability to identify the stage of vitiligo during enrollment in the database may have altered our results, as individuals with active disease have increased levels of IFN-γ. Increased secretion of IFN-γ also potentially helps in the clearance of COVID-19 infection.¹ Future studies should investigate this relationship via planned ­COVID-19 testing, identification of vitiligo stage, and controlling for other associated comorbidities.

To the Editor:

Vitiligo is a depigmentation disorder that results from the loss of melanocytes in the epidermis.¹ The most widely accepted pathophysiology for melanocyte destruction in vitiligo is an autoimmune process involving dysregulated cytokine production and autoreactive T-cell activation.¹ Individuals with cutaneous autoinflammatory conditions currently are vital patient populations warranting research, as their susceptibility to COVID-19 infection may differ from the general population. We previously found a small increased risk for COVID-19 infection in patients with psoriasis,² which suggests that other dermatologic conditions also may impact COVID-19 risk. The risk for COVID-19 infection in patients with vitiligo remains largely unknown. In this retrospective cohort study, we investigated the risk for COVID-19 infection in patients with vitiligo compared with those without vitiligo utilizing claims data from the COVID-19 Research Database (https://covid19researchdatabase.org/).

Claims were evaluated for patients aged 3 years and older with a vitiligo diagnosis (International Classification of Diseases, Tenth Revision [ICD-10] code L80) that was made between January 1, 2016, and January 1, 2020. Individuals without a vitiligo diagnosis during the same period were placed (4:1 ratio) in the control group and were matched with study group patients for age and sex. All comorbidity variables and vitiligo diagnoses were extracted from ICD-10 codes that were given prior to a diagnosis of COVID-19. We then constructed multivariable logistic regression models adjusting for measured confounders to evaluate if vitiligo was associated with higher risk for COVID-19 infection after January 1, 2020.

The vitiligo and nonvitiligo cohorts included 40,363 and 161,452 patients, respectively (Table 1). Logistic regression analysis with adjustment for confounding variables, including high comorbid risk factors (Table 2) revealed that patients with a diagnosis of vitiligo had significantly increased odds of COVID-19 infection compared with patients without vitiligo (adjusted odds ratio [AOR], 1.47; 95% CI, 1.37-1.57; P<.001)(Table 3). Additionally, subgroup logistic analyses for sex, age, and exclusion of patients who were HIV positive revealed that females with vitiligo had higher odds of contracting COVID-19 than males with vitiligo (Table 3).

Our results showed that patients with vitiligo had a higher relative risk for contracting COVID-19 than individuals without vitiligo. It has been reported that the prevalence of COVID-19 is higher among patients with autoimmune diseases compared to the general population.³ Additionally, a handful of vitiligo patients are managed with immunosuppressive agents that may further weaken their immune response.¹ Moreover, survey results from dermatologists managing vitiligo patients revealed that physicians were fairly comfortable prescribing immunosuppressants and encouraging in-office phototherapy during the COVID-19 pandemic.⁴ As a result, more patients may have been attending in-office visits for their phototherapy, which may have increased their risk for COVID-19. Although these factors play a role in ­COVID-19 infection rates, the underlying immune dysregulation in vitiligo in relation to COVID-19 remains unknown and should be further explored.

Our findings are limited by the use of ICD-10 codes, the inability to control for all potential confounding variables, the lack of data regarding the stage of vitiligo, and the absence of data for undiagnosed COVID-19 infections. In addition, patients with vitiligo may be more likely to seek care, potentially increasing their rates of COVID-19 testing. The inability to identify the stage of vitiligo during enrollment in the database may have altered our results, as individuals with active disease have increased levels of IFN-γ. Increased secretion of IFN-γ also potentially helps in the clearance of COVID-19 infection.¹ Future studies should investigate this relationship via planned ­COVID-19 testing, identification of vitiligo stage, and controlling for other associated comorbidities.

To the Editor:

A 32-year-old man presented to our clinic with acute-onset erythroderma associated with severe itching of 1 month’s duration. The patient developed the eruption after receiving the second dose of the Sinopharm BBIBP COVID-19 vaccine (BBIBP-CorV) 2 weeks prior to presentation. His medical history was unremarkable. There was no personal or family history of skin disease and no history of drug intake. Physical examination revealed orange-red erythroderma (Figure 1A) with islands of sparing, keratotic follicular orange-red papules on both legs and feet (Figure 1B), well-defined waxy palmoplantar keratoderma (Figures 1C and 1D), and fine scales on the face and scalp. The clinical and laboratory workup were normal, including a negative test for HIV infection.

Histopathology of two 4-mm punch biopsies of the skin on the trunk and lower limb showed irregular epidermal hyperplasia with thick suprapapillary plates and hypergranulosis (Figure 2A) along with alternating orthokeratosis and parakeratosis in vertical and horizontal directions (checkerboard parakeratosis)(Figure 2B). Follicular plugging with shoulder parakeratosis also was seen. The dermis showed a mild, superficial, perivascular lymphohistiocytic infiltrate. These features were diagnostic of pityriasis rubra pilaris (PRP). The patient received acitretin 25 mg/d and methotrexate 17.5 mg/wk (0.4 mg/kg/wk) and showed marked improvement after 2 months of therapy.

Pityriasis rubra pilaris is a rare papulosquamous skin disease of unknown etiology with several theories including genetic factors, aberrant metabolism of vitamin A, infection, drug reaction, autoimmune disease, and malignancy.¹ Clinically, there are 6 types of PRP: type I (classical adult), type II (atypical adult), type III (classical juvenile), type IV (circumscribed juvenile), type V (atypical juvenile), and type VI (HIV associated). Classic features include orange-red keratotic follicular papules that coalesce into plaques with characteristic islands of sparing.¹

Pityriasis rubra pilaris is a rare sequela following administration of certain vaccines, including diphtheria, pertussis, and tetanus; measles-mumps-rubella; and polio vaccines.^2,3 Among the various skin reactions that have been reported following COVID-19 vaccination, PRP has been reported in 19 patients: 7 (36.8%) after AstraZeneca vaccination, 3 (15.8%) after CoronaVac, 3 (15.8%) after Moderna, 5 (26.3%) after Pfizer-BioNTech,⁴ and 1 (5.3%) after Sinopharm.⁵ Our patient represents an additional case of a reaction after the Sinopharm vaccine. The condition developed after the first dose of vaccine in 11 patients, after the second dose in 6 patients, and after the third dose in 2 patients.

Other papulosquamous skin reactions have been reported after the Sinopharm BBIBP-CorV vaccine including psoriasis, lichen planus, and pityriasis rosea. Skin manifestations occurred sporadically, as some happened after the first or second dose or even after booster doses. The exact pathogenic mechanism(s) underlying the development of these conditions following vaccination still are not understood, though they may be attributed to COVID-19 vaccine–induced immune dysregulation.⁶

Pityriasis rubra pilaris can be self-limited in some cases and may not require treatment. Topical therapies such as keratolytics, emollients, and vitamin D may be utilized, especially for localized disease. Systemic therapy may be needed for refractory cases, including retinoids or immunosuppressive medications such as methotrexate, which is considered a second-line treatment for refractory PRP (after retinoids) and was used in our case. Azathioprine and cyclosporine also may be used. Phototherapy may play a role in PRP treatment, but the response is variable.⁷

Pityriasis rubra pilaris should be added to the list of cutaneous adverse reactions that can occur following vaccination with the Sinopharm BBIBP-CorV vaccine. Dermatologists must be aware of the possibility of vaccine-induced PRP, especially in de novo cases.

To the Editor:

A 32-year-old man presented to our clinic with acute-onset erythroderma associated with severe itching of 1 month’s duration. The patient developed the eruption after receiving the second dose of the Sinopharm BBIBP COVID-19 vaccine (BBIBP-CorV) 2 weeks prior to presentation. His medical history was unremarkable. There was no personal or family history of skin disease and no history of drug intake. Physical examination revealed orange-red erythroderma (Figure 1A) with islands of sparing, keratotic follicular orange-red papules on both legs and feet (Figure 1B), well-defined waxy palmoplantar keratoderma (Figures 1C and 1D), and fine scales on the face and scalp. The clinical and laboratory workup were normal, including a negative test for HIV infection.

Histopathology of two 4-mm punch biopsies of the skin on the trunk and lower limb showed irregular epidermal hyperplasia with thick suprapapillary plates and hypergranulosis (Figure 2A) along with alternating orthokeratosis and parakeratosis in vertical and horizontal directions (checkerboard parakeratosis)(Figure 2B). Follicular plugging with shoulder parakeratosis also was seen. The dermis showed a mild, superficial, perivascular lymphohistiocytic infiltrate. These features were diagnostic of pityriasis rubra pilaris (PRP). The patient received acitretin 25 mg/d and methotrexate 17.5 mg/wk (0.4 mg/kg/wk) and showed marked improvement after 2 months of therapy.

Pityriasis rubra pilaris is a rare papulosquamous skin disease of unknown etiology with several theories including genetic factors, aberrant metabolism of vitamin A, infection, drug reaction, autoimmune disease, and malignancy.¹ Clinically, there are 6 types of PRP: type I (classical adult), type II (atypical adult), type III (classical juvenile), type IV (circumscribed juvenile), type V (atypical juvenile), and type VI (HIV associated). Classic features include orange-red keratotic follicular papules that coalesce into plaques with characteristic islands of sparing.¹

Pityriasis rubra pilaris is a rare sequela following administration of certain vaccines, including diphtheria, pertussis, and tetanus; measles-mumps-rubella; and polio vaccines.^2,3 Among the various skin reactions that have been reported following COVID-19 vaccination, PRP has been reported in 19 patients: 7 (36.8%) after AstraZeneca vaccination, 3 (15.8%) after CoronaVac, 3 (15.8%) after Moderna, 5 (26.3%) after Pfizer-BioNTech,⁴ and 1 (5.3%) after Sinopharm.⁵ Our patient represents an additional case of a reaction after the Sinopharm vaccine. The condition developed after the first dose of vaccine in 11 patients, after the second dose in 6 patients, and after the third dose in 2 patients.

Other papulosquamous skin reactions have been reported after the Sinopharm BBIBP-CorV vaccine including psoriasis, lichen planus, and pityriasis rosea. Skin manifestations occurred sporadically, as some happened after the first or second dose or even after booster doses. The exact pathogenic mechanism(s) underlying the development of these conditions following vaccination still are not understood, though they may be attributed to COVID-19 vaccine–induced immune dysregulation.⁶

Pityriasis rubra pilaris can be self-limited in some cases and may not require treatment. Topical therapies such as keratolytics, emollients, and vitamin D may be utilized, especially for localized disease. Systemic therapy may be needed for refractory cases, including retinoids or immunosuppressive medications such as methotrexate, which is considered a second-line treatment for refractory PRP (after retinoids) and was used in our case. Azathioprine and cyclosporine also may be used. Phototherapy may play a role in PRP treatment, but the response is variable.⁷

Pityriasis rubra pilaris should be added to the list of cutaneous adverse reactions that can occur following vaccination with the Sinopharm BBIBP-CorV vaccine. Dermatologists must be aware of the possibility of vaccine-induced PRP, especially in de novo cases.

To the Editor:

A 32-year-old man presented to our clinic with acute-onset erythroderma associated with severe itching of 1 month’s duration. The patient developed the eruption after receiving the second dose of the Sinopharm BBIBP COVID-19 vaccine (BBIBP-CorV) 2 weeks prior to presentation. His medical history was unremarkable. There was no personal or family history of skin disease and no history of drug intake. Physical examination revealed orange-red erythroderma (Figure 1A) with islands of sparing, keratotic follicular orange-red papules on both legs and feet (Figure 1B), well-defined waxy palmoplantar keratoderma (Figures 1C and 1D), and fine scales on the face and scalp. The clinical and laboratory workup were normal, including a negative test for HIV infection.

Histopathology of two 4-mm punch biopsies of the skin on the trunk and lower limb showed irregular epidermal hyperplasia with thick suprapapillary plates and hypergranulosis (Figure 2A) along with alternating orthokeratosis and parakeratosis in vertical and horizontal directions (checkerboard parakeratosis)(Figure 2B). Follicular plugging with shoulder parakeratosis also was seen. The dermis showed a mild, superficial, perivascular lymphohistiocytic infiltrate. These features were diagnostic of pityriasis rubra pilaris (PRP). The patient received acitretin 25 mg/d and methotrexate 17.5 mg/wk (0.4 mg/kg/wk) and showed marked improvement after 2 months of therapy.

Pityriasis rubra pilaris is a rare papulosquamous skin disease of unknown etiology with several theories including genetic factors, aberrant metabolism of vitamin A, infection, drug reaction, autoimmune disease, and malignancy.¹ Clinically, there are 6 types of PRP: type I (classical adult), type II (atypical adult), type III (classical juvenile), type IV (circumscribed juvenile), type V (atypical juvenile), and type VI (HIV associated). Classic features include orange-red keratotic follicular papules that coalesce into plaques with characteristic islands of sparing.¹

Pityriasis rubra pilaris is a rare sequela following administration of certain vaccines, including diphtheria, pertussis, and tetanus; measles-mumps-rubella; and polio vaccines.^2,3 Among the various skin reactions that have been reported following COVID-19 vaccination, PRP has been reported in 19 patients: 7 (36.8%) after AstraZeneca vaccination, 3 (15.8%) after CoronaVac, 3 (15.8%) after Moderna, 5 (26.3%) after Pfizer-BioNTech,⁴ and 1 (5.3%) after Sinopharm.⁵ Our patient represents an additional case of a reaction after the Sinopharm vaccine. The condition developed after the first dose of vaccine in 11 patients, after the second dose in 6 patients, and after the third dose in 2 patients.

Other papulosquamous skin reactions have been reported after the Sinopharm BBIBP-CorV vaccine including psoriasis, lichen planus, and pityriasis rosea. Skin manifestations occurred sporadically, as some happened after the first or second dose or even after booster doses. The exact pathogenic mechanism(s) underlying the development of these conditions following vaccination still are not understood, though they may be attributed to COVID-19 vaccine–induced immune dysregulation.⁶

Pityriasis rubra pilaris can be self-limited in some cases and may not require treatment. Topical therapies such as keratolytics, emollients, and vitamin D may be utilized, especially for localized disease. Systemic therapy may be needed for refractory cases, including retinoids or immunosuppressive medications such as methotrexate, which is considered a second-line treatment for refractory PRP (after retinoids) and was used in our case. Azathioprine and cyclosporine also may be used. Phototherapy may play a role in PRP treatment, but the response is variable.⁷

Pityriasis rubra pilaris should be added to the list of cutaneous adverse reactions that can occur following vaccination with the Sinopharm BBIBP-CorV vaccine. Dermatologists must be aware of the possibility of vaccine-induced PRP, especially in de novo cases.

Approximately 108 million individuals have been forcibly displaced across the globe as of 2022, 35 million of whom are formally designated as refugees.^1,2 The United States has coordinated resettlement of more refugee populations than any other country; the most common countries of origin are the Democratic Republic of the Congo, Syria, Afghanistan, and Myanmar.³ In 2021, policy to increase the number of refugees resettled in the United States by more than 700% (from 15,000 up to 125,000) was established; since enactment, the United States has seen more than double the refugee arrivals in 2023 than the prior year, making medical care for this population increasingly relevant for the dermatologist.⁴

Understanding how to care for this population begins with an accurate understanding of the term refugee. The United Nations defines a refugee as a person who is unwilling or unable to return to their country of nationality because of persecution or well-founded fear of persecution due to race, religion, nationality, membership in a particular social group, or political opinion. This term grants a protected status under international law and encompasses access to travel assistance, housing, cultural orientation, and medical evaluation upon resettlement.^5,6

The burden of treatable dermatologic conditions in refugee populations ranges from 19% to 96% in the literature^7,8 and varies from inflammatory disorders to infectious and parasitic diseases.⁹ In one study of 6899 displaced individuals in Greece, the prevalence of dermatologic conditions was higher than traumatic injury, cardiac disease, psychological conditions, and dental disease.¹⁰

When outlining differential diagnoses for parasitic infestations of the skin that affect refugee populations, helpful considerations include the individual’s country of origin, route traveled, and method of travel.¹¹ Parasitic infestations specifically are more common in refugee populations when there are barriers to basic hygiene, crowded living or travel conditions, or lack of access to health care, which they may experience at any point in their home country, during travel, or in resettlement housing.⁸

Even with limited examination and diagnostic resources, the skin is the most accessible first indication of patients’ overall well-being and often provides simple diagnostic clues—in combination with contextualization of the patient’s unique circumstances—necessary for successful diagnosis and treatment of scabies and pediculosis.¹² The dermatologist working with refugee populations may be the first set of eyes available and trained to discern skin infestations and therefore has the potential to improve overall outcomes.

Some parasitic infestations in refugee populations may fall under the category of neglected tropical diseases, including scabies, ascariasis, trypanosomiasis, leishmaniasis, and schistosomiasis; they affect an estimated 1 billion individuals across the globe but historically have been underrepresented in the literature and in health policy due in part to limited access to care.¹³ This review will focus on infestations by the scabies mite (Sarcoptes scabiei var hominis) and the human louse, as these frequently are encountered, easily diagnosed, and treatable by trained clinicians, even in resource-limited settings.

Scabies

Scabies is a parasitic skin infestation caused by the 8-legged mite Sarcoptes scabiei var hominis. The female mite begins the infestation process via penetration of the epidermis, particularly the stratum corneum, and commences laying eggs (Figure 1). The subsequent larvae emerge 48 to 72 hours later and remain burrowed in the epidermis. The larvae mature over the next 10 to 14 days and continue the reproductive cycle.^14,15 Symptoms of infestation occurs due to a hypersensitivity reaction to the mite and its by-products.¹⁶ Transmission of the mite primarily occurs via direct (skin-to-skin) contact with infected individuals or environmental surfaces for 24 to36 hours in specific conditions, though the latter source has been debated in the literature.

The method of transmission is particularly important when considering care for refugee populations. Scabies is found most often in those living in or traveling from tropical regions including East Asia, Southeast Asia, Oceania, and Latin America.¹⁷ In displaced or refugee populations, a lack of access to basic hygiene, extended travel in close quarters, and suboptimal health care access all may lead to an increased incidence of untreated scabies infestations.¹⁸ Scabies is more prevalent in children, with increased potential for secondary bacterial infections with Streptococcus and Staphylococcus species due to excoriation in unsanitary conditions. Secondary infection with Streptococcus pyogenes can lead to acute poststreptococcal glomerulonephritis, which accounts for a large burden of chronic kidney disease in affected populations.¹⁹ However, scabies may be found in any population, regardless of hygiene or health care access. Treating health care providers should keep a broad differential.

Presentation—The latency of scabies symptoms is 2 to 6 weeks in a primary outbreak and may be as short as 1 to 3 days with re-infestation, following the course of delayed-type hypersensitivity.²⁰ The initial hallmark symptom is pruritus with increased severity in the evening. Visible lesions, excoriations, and burrows associated with scattered vesicles or pustules may be seen over the web spaces of the hands and feet, volar surfaces of the wrists, axillae, waist, genitalia, inner thighs, or buttocks.¹⁹ Chronic infestation often manifests with genital nodules. In populations with limited access to health care, there are reports of a sensitization phenomenon in which the individual may become less symptomatic after 4 to 6 weeks and yet be a potential carrier of the mite.²¹

Those with compromised immune function, such as individuals living with HIV or severe malnutrition, may present with crusted scabies, a variant that manifests as widespread hyperkeratotic scaling with more pronounced involvement of the head, neck, and acral areas. In contrast to classic scabies, crusted scabies is associated with minimal pruritus.²²

Diagnosis—The diagnosis of scabies is largely clinical with confirmation through skin scrapings. The International Alliance for Control of Scabies has established diagnostic criteria that include a combination of clinical findings, history, and visualization of mites.²³ A dermatologist working with refugee populations may employ any combination of history (eg, nocturnal itch, exposure to an affected individual) or clinical findings along with a high degree of suspicion in those with elevated risk. Visualization of mites is helpful to confirm the diagnosis and may be completed with the application of mineral oil at the terminal end of a burrow, skin scraping with a surgical blade or needle, and examination under light microscopy.

Treatment—First-line treatment for scabies consists of application of permethrin cream 5% on the skin of the neck to the soles of the feet, which is to be left on for 8 to 14 hours followed by rinsing. Re-application is recommended in 1 to 2 weeks. Oral ivermectin is a reasonable alternative to permethrin cream due to its low cost and easy administration in large affected groups. It is not labeled for use in pregnant women or children weighing less than 15 kg but has no selective fetal toxicity. Treatment of scabies with ivermectin has the benefit of treating many other parasitic infections. Both medications are on the World Health Organization Model List of Essential Medications and are widely available for treating providers, even in resource-limited settings.²⁴

Much of the world still uses benzyl benzoate or precipitated sulfur ointment to treat scabies, and some botanicals used in folk medicine have genuine antiscabetic properties. Pruritus may persist for 1 to 4 weeks following treatment and does not indicate treatment failure. Topical camphor and menthol preparations, low-potency topical corticosteroids, or emollients all may be employed for relief.²⁵ Sarna is a Spanish term for scabies and has become the proprietary name for topical antipruritic agents. Additional methods of treatment and prevention include washing clothes and linens in hot water and drying on high heat. If machine washing is not available, clothing and linens may be sealed in a plastic bag for 72 hours.

Pediculosis

Pediculosis is an infestation caused by the ectoparasite Pediculus humanus, an obligate, sesame seed–sized louse that feeds exclusively on the blood of its host (Figure 2).²⁶ Of the lice species, 2 require humans as hosts; one is P humanus and the other is Pthirus pubis (pubic lice). Pediculus humanus may be further classified into morphologies based largely on the affected area: body (P humanus corporis) or head (P humanus capitis), both of which will be discussed.²⁷

Lice primarily attach to clothing and hair shafts, then transfer to the skin for blood feeds. Females lay eggs that hatch 6 to 10 days later, subsequently maturing into adults. The lifespan of these parasites with regular access to a host is 1 to 3 months for head lice and 18 days for body lice vs only 3 to 5 days without a host.²⁸ Transmission of P humanus capitis primarily occurs via direct contact with affected individuals, either head-to-head contact or sharing of items such as brushes and headscarves; P humanus corporis also may be transmitted via direct contact with affected individuals or clothing.

Pediculosis is an important infestation to consider when providing care for refugee populations. Risk factors include lack of access to basic hygiene, including regular bathing or laundering of clothing, and crowded conditions that make direct person-to-person contact with affected individuals more likely.²⁹ Body lice are associated more often with domestic turbulence and displaced populations³⁰ in comparison to head lice, which have broad demographic variables, most often affecting females and children.²⁸ Fatty acids in adult male sebum make the scalp less hospitable to lice.

Presentation—The most common clinical manifestation of pediculosis is pruritus. Cutaneous findings can include papules, wheals, or hemorrhagic puncta secondary to the louse bite. Due to the Tyndall effect of deep hemosiderin pigment, blue-grey macules termed maculae ceruleae (Figure 3) also may be present in chronic infestations of pediculosis pubis, in contrast to pediculosis capitis or corporis.³¹ Body louse infestation is associated with a general pruritus concentrated on the neck, shoulders, and waist—areas where clothing makes the most direct contact. Lesions may be visible and include eczematous patches with excoriation and possible secondary bacterial infection. Chronic infestation may exhibit lichenification or hyperpigmentation in associated areas. Head lice most often manifest with localized scalp pruritus and associated excoriation and cervical or occipital lymphadenopathy.³²

Diagnosis—The diagnosis of pediculosis is clinical, with confirmation requiring direct examination of the insect or nits (the egg case of the parasite)(Figure 4). Body lice and associated nits can be visualized on clothing seams near areas of highest body temperature, particularly the waistband. Head lice may be visualized crawling on hair shafts or on a louse comb. Nits are firmly attached to hair shafts and are visible to the naked eye, whereas pseudonits slide freely along the hair shaft and are not a manifestation of louse infestation (Figure 5).³¹

Treatment—Treatment varies by affected area. Pediculosis corporis may be treated with permethrin cream 5% applied to the entire body and left on for 8 to 10 hours, but this may not be necessary if facilities are available to wash and dry clothing.³³ The use of oral ivermectin and permethrin-impregnated underwear both have been proposed.^34,35 Treatment of pediculosis capitis may be accomplished with a variety of topical pediculicides including permethrin, pyrethrum with piperonyl butoxide, dimethicone, malathion, benzyl alcohol, spinosad, and topical ivermectin.²² Topical corticosteroids or emollients may be employed for residual pruritus.

Equally important is environmental elimination of infestation. Clothing should be discarded if possible or washed and dried using high heat. If neither approach is possible or appropriate, clothing may be sealed in a plastic bag for 2 weeks or treated with a pediculicide. Nit combing is an important adjunct in the treatment of pediculosis capitis.³⁶ It is important to encourage return to work and/or school immediately after treatment. “No nit” policies are more harmful to education than helpful for prevention of investation.³⁷

Pediculosis corporis may transmit infectious agents including Bartonella quintana, (trench fever, endocarditis, bacillary angiomatosis), Borrelia recurrentis (louse-borne relapsing fever), and Rickettsia prowazekii (epidemic typhus).^31,38,39 Additionally, severe pediculosis infestations have the potential to cause chronic blood loss in affected populations. In a study of patients with active pediculosis infestation, mean hemoglobin values were found to be 2.5 g/dL lower than a matched population without infestation.⁴⁰ It is important to consider pediculosis as a risk for iron-deficiency anemia in populations who are known to lack access to regular medical evaluation.⁴¹

Future Considerations

Increased access to tools and education for clinicians treating refugee populations is key to reducing the burden of parasitic skin disease and related morbidity and mortality in vulnerable groups both domestically and globally. One such tool, the Skin NTDs App, was launched by the World Health Organization in 2020. It is available for free for Android and iOS devices to assist clinicians in the field with the diagnosis and treatment of neglected tropical diseases—including scabies—that may affect refugee populations.⁴²

Additionally, to both improve access and limit preventable sequelae, future investigations into appropriate models of community-based care are paramount. The model of community-based care is centered on the idea of care provision that prioritizes safety, accessibility, affordability, and acceptability in an environment closest to vulnerable populations. The largest dermatologic society, the International League of Dermatological Societies, formed a Migrant Health Dermatology Working Group that prioritizes understanding and improving care for refugee and migrant populations; this group hosted a summit in 2022, bringing together international subject matter leaders to discuss such models of care and set goals for the creation of tool kits for patients, frontline health care workers, and dermatologists.⁴³

Conclusion

Improvement in dermatologic care of refugee populations includes provision of culturally and linguistically appropriate care by trained clinicians, adequate access to the most essential medications, and basic physical or legal access to health care systems in general.^8,11,44 Parasitic infestations have the potential to remain asymptomatic for extended periods of time and result in spread to potentially nonendemic regions of resettlement.⁴⁵ Additionally, the psychosocial well-being of refugee populations upon resettlement may be negatively affected by stigma of disease processes such as scabies and pediculosis, leading to additional barriers to successful re-entry into the patient’s new environment.⁴⁶ Therefore, proper screening, diagnosis, and treatment of the most common parasitic infestations in this population have great potential to improve outcomes for large groups across the globe.

Approximately 108 million individuals have been forcibly displaced across the globe as of 2022, 35 million of whom are formally designated as refugees.^1,2 The United States has coordinated resettlement of more refugee populations than any other country; the most common countries of origin are the Democratic Republic of the Congo, Syria, Afghanistan, and Myanmar.³ In 2021, policy to increase the number of refugees resettled in the United States by more than 700% (from 15,000 up to 125,000) was established; since enactment, the United States has seen more than double the refugee arrivals in 2023 than the prior year, making medical care for this population increasingly relevant for the dermatologist.⁴

Understanding how to care for this population begins with an accurate understanding of the term refugee. The United Nations defines a refugee as a person who is unwilling or unable to return to their country of nationality because of persecution or well-founded fear of persecution due to race, religion, nationality, membership in a particular social group, or political opinion. This term grants a protected status under international law and encompasses access to travel assistance, housing, cultural orientation, and medical evaluation upon resettlement.^5,6

The burden of treatable dermatologic conditions in refugee populations ranges from 19% to 96% in the literature^7,8 and varies from inflammatory disorders to infectious and parasitic diseases.⁹ In one study of 6899 displaced individuals in Greece, the prevalence of dermatologic conditions was higher than traumatic injury, cardiac disease, psychological conditions, and dental disease.¹⁰

When outlining differential diagnoses for parasitic infestations of the skin that affect refugee populations, helpful considerations include the individual’s country of origin, route traveled, and method of travel.¹¹ Parasitic infestations specifically are more common in refugee populations when there are barriers to basic hygiene, crowded living or travel conditions, or lack of access to health care, which they may experience at any point in their home country, during travel, or in resettlement housing.⁸

Even with limited examination and diagnostic resources, the skin is the most accessible first indication of patients’ overall well-being and often provides simple diagnostic clues—in combination with contextualization of the patient’s unique circumstances—necessary for successful diagnosis and treatment of scabies and pediculosis.¹² The dermatologist working with refugee populations may be the first set of eyes available and trained to discern skin infestations and therefore has the potential to improve overall outcomes.

Some parasitic infestations in refugee populations may fall under the category of neglected tropical diseases, including scabies, ascariasis, trypanosomiasis, leishmaniasis, and schistosomiasis; they affect an estimated 1 billion individuals across the globe but historically have been underrepresented in the literature and in health policy due in part to limited access to care.¹³ This review will focus on infestations by the scabies mite (Sarcoptes scabiei var hominis) and the human louse, as these frequently are encountered, easily diagnosed, and treatable by trained clinicians, even in resource-limited settings.

Scabies

Scabies is a parasitic skin infestation caused by the 8-legged mite Sarcoptes scabiei var hominis. The female mite begins the infestation process via penetration of the epidermis, particularly the stratum corneum, and commences laying eggs (Figure 1). The subsequent larvae emerge 48 to 72 hours later and remain burrowed in the epidermis. The larvae mature over the next 10 to 14 days and continue the reproductive cycle.^14,15 Symptoms of infestation occurs due to a hypersensitivity reaction to the mite and its by-products.¹⁶ Transmission of the mite primarily occurs via direct (skin-to-skin) contact with infected individuals or environmental surfaces for 24 to36 hours in specific conditions, though the latter source has been debated in the literature.

The method of transmission is particularly important when considering care for refugee populations. Scabies is found most often in those living in or traveling from tropical regions including East Asia, Southeast Asia, Oceania, and Latin America.¹⁷ In displaced or refugee populations, a lack of access to basic hygiene, extended travel in close quarters, and suboptimal health care access all may lead to an increased incidence of untreated scabies infestations.¹⁸ Scabies is more prevalent in children, with increased potential for secondary bacterial infections with Streptococcus and Staphylococcus species due to excoriation in unsanitary conditions. Secondary infection with Streptococcus pyogenes can lead to acute poststreptococcal glomerulonephritis, which accounts for a large burden of chronic kidney disease in affected populations.¹⁹ However, scabies may be found in any population, regardless of hygiene or health care access. Treating health care providers should keep a broad differential.

Presentation—The latency of scabies symptoms is 2 to 6 weeks in a primary outbreak and may be as short as 1 to 3 days with re-infestation, following the course of delayed-type hypersensitivity.²⁰ The initial hallmark symptom is pruritus with increased severity in the evening. Visible lesions, excoriations, and burrows associated with scattered vesicles or pustules may be seen over the web spaces of the hands and feet, volar surfaces of the wrists, axillae, waist, genitalia, inner thighs, or buttocks.¹⁹ Chronic infestation often manifests with genital nodules. In populations with limited access to health care, there are reports of a sensitization phenomenon in which the individual may become less symptomatic after 4 to 6 weeks and yet be a potential carrier of the mite.²¹

Those with compromised immune function, such as individuals living with HIV or severe malnutrition, may present with crusted scabies, a variant that manifests as widespread hyperkeratotic scaling with more pronounced involvement of the head, neck, and acral areas. In contrast to classic scabies, crusted scabies is associated with minimal pruritus.²²

Diagnosis—The diagnosis of scabies is largely clinical with confirmation through skin scrapings. The International Alliance for Control of Scabies has established diagnostic criteria that include a combination of clinical findings, history, and visualization of mites.²³ A dermatologist working with refugee populations may employ any combination of history (eg, nocturnal itch, exposure to an affected individual) or clinical findings along with a high degree of suspicion in those with elevated risk. Visualization of mites is helpful to confirm the diagnosis and may be completed with the application of mineral oil at the terminal end of a burrow, skin scraping with a surgical blade or needle, and examination under light microscopy.

Treatment—First-line treatment for scabies consists of application of permethrin cream 5% on the skin of the neck to the soles of the feet, which is to be left on for 8 to 14 hours followed by rinsing. Re-application is recommended in 1 to 2 weeks. Oral ivermectin is a reasonable alternative to permethrin cream due to its low cost and easy administration in large affected groups. It is not labeled for use in pregnant women or children weighing less than 15 kg but has no selective fetal toxicity. Treatment of scabies with ivermectin has the benefit of treating many other parasitic infections. Both medications are on the World Health Organization Model List of Essential Medications and are widely available for treating providers, even in resource-limited settings.²⁴

Much of the world still uses benzyl benzoate or precipitated sulfur ointment to treat scabies, and some botanicals used in folk medicine have genuine antiscabetic properties. Pruritus may persist for 1 to 4 weeks following treatment and does not indicate treatment failure. Topical camphor and menthol preparations, low-potency topical corticosteroids, or emollients all may be employed for relief.²⁵ Sarna is a Spanish term for scabies and has become the proprietary name for topical antipruritic agents. Additional methods of treatment and prevention include washing clothes and linens in hot water and drying on high heat. If machine washing is not available, clothing and linens may be sealed in a plastic bag for 72 hours.

Pediculosis

Pediculosis is an infestation caused by the ectoparasite Pediculus humanus, an obligate, sesame seed–sized louse that feeds exclusively on the blood of its host (Figure 2).²⁶ Of the lice species, 2 require humans as hosts; one is P humanus and the other is Pthirus pubis (pubic lice). Pediculus humanus may be further classified into morphologies based largely on the affected area: body (P humanus corporis) or head (P humanus capitis), both of which will be discussed.²⁷

Lice primarily attach to clothing and hair shafts, then transfer to the skin for blood feeds. Females lay eggs that hatch 6 to 10 days later, subsequently maturing into adults. The lifespan of these parasites with regular access to a host is 1 to 3 months for head lice and 18 days for body lice vs only 3 to 5 days without a host.²⁸ Transmission of P humanus capitis primarily occurs via direct contact with affected individuals, either head-to-head contact or sharing of items such as brushes and headscarves; P humanus corporis also may be transmitted via direct contact with affected individuals or clothing.

Pediculosis is an important infestation to consider when providing care for refugee populations. Risk factors include lack of access to basic hygiene, including regular bathing or laundering of clothing, and crowded conditions that make direct person-to-person contact with affected individuals more likely.²⁹ Body lice are associated more often with domestic turbulence and displaced populations³⁰ in comparison to head lice, which have broad demographic variables, most often affecting females and children.²⁸ Fatty acids in adult male sebum make the scalp less hospitable to lice.

Presentation—The most common clinical manifestation of pediculosis is pruritus. Cutaneous findings can include papules, wheals, or hemorrhagic puncta secondary to the louse bite. Due to the Tyndall effect of deep hemosiderin pigment, blue-grey macules termed maculae ceruleae (Figure 3) also may be present in chronic infestations of pediculosis pubis, in contrast to pediculosis capitis or corporis.³¹ Body louse infestation is associated with a general pruritus concentrated on the neck, shoulders, and waist—areas where clothing makes the most direct contact. Lesions may be visible and include eczematous patches with excoriation and possible secondary bacterial infection. Chronic infestation may exhibit lichenification or hyperpigmentation in associated areas. Head lice most often manifest with localized scalp pruritus and associated excoriation and cervical or occipital lymphadenopathy.³²

Diagnosis—The diagnosis of pediculosis is clinical, with confirmation requiring direct examination of the insect or nits (the egg case of the parasite)(Figure 4). Body lice and associated nits can be visualized on clothing seams near areas of highest body temperature, particularly the waistband. Head lice may be visualized crawling on hair shafts or on a louse comb. Nits are firmly attached to hair shafts and are visible to the naked eye, whereas pseudonits slide freely along the hair shaft and are not a manifestation of louse infestation (Figure 5).³¹

Treatment—Treatment varies by affected area. Pediculosis corporis may be treated with permethrin cream 5% applied to the entire body and left on for 8 to 10 hours, but this may not be necessary if facilities are available to wash and dry clothing.³³ The use of oral ivermectin and permethrin-impregnated underwear both have been proposed.^34,35 Treatment of pediculosis capitis may be accomplished with a variety of topical pediculicides including permethrin, pyrethrum with piperonyl butoxide, dimethicone, malathion, benzyl alcohol, spinosad, and topical ivermectin.²² Topical corticosteroids or emollients may be employed for residual pruritus.

Equally important is environmental elimination of infestation. Clothing should be discarded if possible or washed and dried using high heat. If neither approach is possible or appropriate, clothing may be sealed in a plastic bag for 2 weeks or treated with a pediculicide. Nit combing is an important adjunct in the treatment of pediculosis capitis.³⁶ It is important to encourage return to work and/or school immediately after treatment. “No nit” policies are more harmful to education than helpful for prevention of investation.³⁷

Pediculosis corporis may transmit infectious agents including Bartonella quintana, (trench fever, endocarditis, bacillary angiomatosis), Borrelia recurrentis (louse-borne relapsing fever), and Rickettsia prowazekii (epidemic typhus).^31,38,39 Additionally, severe pediculosis infestations have the potential to cause chronic blood loss in affected populations. In a study of patients with active pediculosis infestation, mean hemoglobin values were found to be 2.5 g/dL lower than a matched population without infestation.⁴⁰ It is important to consider pediculosis as a risk for iron-deficiency anemia in populations who are known to lack access to regular medical evaluation.⁴¹

Future Considerations

Increased access to tools and education for clinicians treating refugee populations is key to reducing the burden of parasitic skin disease and related morbidity and mortality in vulnerable groups both domestically and globally. One such tool, the Skin NTDs App, was launched by the World Health Organization in 2020. It is available for free for Android and iOS devices to assist clinicians in the field with the diagnosis and treatment of neglected tropical diseases—including scabies—that may affect refugee populations.⁴²

Additionally, to both improve access and limit preventable sequelae, future investigations into appropriate models of community-based care are paramount. The model of community-based care is centered on the idea of care provision that prioritizes safety, accessibility, affordability, and acceptability in an environment closest to vulnerable populations. The largest dermatologic society, the International League of Dermatological Societies, formed a Migrant Health Dermatology Working Group that prioritizes understanding and improving care for refugee and migrant populations; this group hosted a summit in 2022, bringing together international subject matter leaders to discuss such models of care and set goals for the creation of tool kits for patients, frontline health care workers, and dermatologists.⁴³

Conclusion

Improvement in dermatologic care of refugee populations includes provision of culturally and linguistically appropriate care by trained clinicians, adequate access to the most essential medications, and basic physical or legal access to health care systems in general.^8,11,44 Parasitic infestations have the potential to remain asymptomatic for extended periods of time and result in spread to potentially nonendemic regions of resettlement.⁴⁵ Additionally, the psychosocial well-being of refugee populations upon resettlement may be negatively affected by stigma of disease processes such as scabies and pediculosis, leading to additional barriers to successful re-entry into the patient’s new environment.⁴⁶ Therefore, proper screening, diagnosis, and treatment of the most common parasitic infestations in this population have great potential to improve outcomes for large groups across the globe.

Approximately 108 million individuals have been forcibly displaced across the globe as of 2022, 35 million of whom are formally designated as refugees.^1,2 The United States has coordinated resettlement of more refugee populations than any other country; the most common countries of origin are the Democratic Republic of the Congo, Syria, Afghanistan, and Myanmar.³ In 2021, policy to increase the number of refugees resettled in the United States by more than 700% (from 15,000 up to 125,000) was established; since enactment, the United States has seen more than double the refugee arrivals in 2023 than the prior year, making medical care for this population increasingly relevant for the dermatologist.⁴

Understanding how to care for this population begins with an accurate understanding of the term refugee. The United Nations defines a refugee as a person who is unwilling or unable to return to their country of nationality because of persecution or well-founded fear of persecution due to race, religion, nationality, membership in a particular social group, or political opinion. This term grants a protected status under international law and encompasses access to travel assistance, housing, cultural orientation, and medical evaluation upon resettlement.^5,6

The burden of treatable dermatologic conditions in refugee populations ranges from 19% to 96% in the literature^7,8 and varies from inflammatory disorders to infectious and parasitic diseases.⁹ In one study of 6899 displaced individuals in Greece, the prevalence of dermatologic conditions was higher than traumatic injury, cardiac disease, psychological conditions, and dental disease.¹⁰

When outlining differential diagnoses for parasitic infestations of the skin that affect refugee populations, helpful considerations include the individual’s country of origin, route traveled, and method of travel.¹¹ Parasitic infestations specifically are more common in refugee populations when there are barriers to basic hygiene, crowded living or travel conditions, or lack of access to health care, which they may experience at any point in their home country, during travel, or in resettlement housing.⁸

Even with limited examination and diagnostic resources, the skin is the most accessible first indication of patients’ overall well-being and often provides simple diagnostic clues—in combination with contextualization of the patient’s unique circumstances—necessary for successful diagnosis and treatment of scabies and pediculosis.¹² The dermatologist working with refugee populations may be the first set of eyes available and trained to discern skin infestations and therefore has the potential to improve overall outcomes.

Some parasitic infestations in refugee populations may fall under the category of neglected tropical diseases, including scabies, ascariasis, trypanosomiasis, leishmaniasis, and schistosomiasis; they affect an estimated 1 billion individuals across the globe but historically have been underrepresented in the literature and in health policy due in part to limited access to care.¹³ This review will focus on infestations by the scabies mite (Sarcoptes scabiei var hominis) and the human louse, as these frequently are encountered, easily diagnosed, and treatable by trained clinicians, even in resource-limited settings.

Scabies

Scabies is a parasitic skin infestation caused by the 8-legged mite Sarcoptes scabiei var hominis. The female mite begins the infestation process via penetration of the epidermis, particularly the stratum corneum, and commences laying eggs (Figure 1). The subsequent larvae emerge 48 to 72 hours later and remain burrowed in the epidermis. The larvae mature over the next 10 to 14 days and continue the reproductive cycle.^14,15 Symptoms of infestation occurs due to a hypersensitivity reaction to the mite and its by-products.¹⁶ Transmission of the mite primarily occurs via direct (skin-to-skin) contact with infected individuals or environmental surfaces for 24 to36 hours in specific conditions, though the latter source has been debated in the literature.

The method of transmission is particularly important when considering care for refugee populations. Scabies is found most often in those living in or traveling from tropical regions including East Asia, Southeast Asia, Oceania, and Latin America.¹⁷ In displaced or refugee populations, a lack of access to basic hygiene, extended travel in close quarters, and suboptimal health care access all may lead to an increased incidence of untreated scabies infestations.¹⁸ Scabies is more prevalent in children, with increased potential for secondary bacterial infections with Streptococcus and Staphylococcus species due to excoriation in unsanitary conditions. Secondary infection with Streptococcus pyogenes can lead to acute poststreptococcal glomerulonephritis, which accounts for a large burden of chronic kidney disease in affected populations.¹⁹ However, scabies may be found in any population, regardless of hygiene or health care access. Treating health care providers should keep a broad differential.

Presentation—The latency of scabies symptoms is 2 to 6 weeks in a primary outbreak and may be as short as 1 to 3 days with re-infestation, following the course of delayed-type hypersensitivity.²⁰ The initial hallmark symptom is pruritus with increased severity in the evening. Visible lesions, excoriations, and burrows associated with scattered vesicles or pustules may be seen over the web spaces of the hands and feet, volar surfaces of the wrists, axillae, waist, genitalia, inner thighs, or buttocks.¹⁹ Chronic infestation often manifests with genital nodules. In populations with limited access to health care, there are reports of a sensitization phenomenon in which the individual may become less symptomatic after 4 to 6 weeks and yet be a potential carrier of the mite.²¹

Those with compromised immune function, such as individuals living with HIV or severe malnutrition, may present with crusted scabies, a variant that manifests as widespread hyperkeratotic scaling with more pronounced involvement of the head, neck, and acral areas. In contrast to classic scabies, crusted scabies is associated with minimal pruritus.²²

Diagnosis—The diagnosis of scabies is largely clinical with confirmation through skin scrapings. The International Alliance for Control of Scabies has established diagnostic criteria that include a combination of clinical findings, history, and visualization of mites.²³ A dermatologist working with refugee populations may employ any combination of history (eg, nocturnal itch, exposure to an affected individual) or clinical findings along with a high degree of suspicion in those with elevated risk. Visualization of mites is helpful to confirm the diagnosis and may be completed with the application of mineral oil at the terminal end of a burrow, skin scraping with a surgical blade or needle, and examination under light microscopy.

Treatment—First-line treatment for scabies consists of application of permethrin cream 5% on the skin of the neck to the soles of the feet, which is to be left on for 8 to 14 hours followed by rinsing. Re-application is recommended in 1 to 2 weeks. Oral ivermectin is a reasonable alternative to permethrin cream due to its low cost and easy administration in large affected groups. It is not labeled for use in pregnant women or children weighing less than 15 kg but has no selective fetal toxicity. Treatment of scabies with ivermectin has the benefit of treating many other parasitic infections. Both medications are on the World Health Organization Model List of Essential Medications and are widely available for treating providers, even in resource-limited settings.²⁴

Much of the world still uses benzyl benzoate or precipitated sulfur ointment to treat scabies, and some botanicals used in folk medicine have genuine antiscabetic properties. Pruritus may persist for 1 to 4 weeks following treatment and does not indicate treatment failure. Topical camphor and menthol preparations, low-potency topical corticosteroids, or emollients all may be employed for relief.²⁵ Sarna is a Spanish term for scabies and has become the proprietary name for topical antipruritic agents. Additional methods of treatment and prevention include washing clothes and linens in hot water and drying on high heat. If machine washing is not available, clothing and linens may be sealed in a plastic bag for 72 hours.

Pediculosis

Pediculosis is an infestation caused by the ectoparasite Pediculus humanus, an obligate, sesame seed–sized louse that feeds exclusively on the blood of its host (Figure 2).²⁶ Of the lice species, 2 require humans as hosts; one is P humanus and the other is Pthirus pubis (pubic lice). Pediculus humanus may be further classified into morphologies based largely on the affected area: body (P humanus corporis) or head (P humanus capitis), both of which will be discussed.²⁷

Lice primarily attach to clothing and hair shafts, then transfer to the skin for blood feeds. Females lay eggs that hatch 6 to 10 days later, subsequently maturing into adults. The lifespan of these parasites with regular access to a host is 1 to 3 months for head lice and 18 days for body lice vs only 3 to 5 days without a host.²⁸ Transmission of P humanus capitis primarily occurs via direct contact with affected individuals, either head-to-head contact or sharing of items such as brushes and headscarves; P humanus corporis also may be transmitted via direct contact with affected individuals or clothing.

Pediculosis is an important infestation to consider when providing care for refugee populations. Risk factors include lack of access to basic hygiene, including regular bathing or laundering of clothing, and crowded conditions that make direct person-to-person contact with affected individuals more likely.²⁹ Body lice are associated more often with domestic turbulence and displaced populations³⁰ in comparison to head lice, which have broad demographic variables, most often affecting females and children.²⁸ Fatty acids in adult male sebum make the scalp less hospitable to lice.

Presentation—The most common clinical manifestation of pediculosis is pruritus. Cutaneous findings can include papules, wheals, or hemorrhagic puncta secondary to the louse bite. Due to the Tyndall effect of deep hemosiderin pigment, blue-grey macules termed maculae ceruleae (Figure 3) also may be present in chronic infestations of pediculosis pubis, in contrast to pediculosis capitis or corporis.³¹ Body louse infestation is associated with a general pruritus concentrated on the neck, shoulders, and waist—areas where clothing makes the most direct contact. Lesions may be visible and include eczematous patches with excoriation and possible secondary bacterial infection. Chronic infestation may exhibit lichenification or hyperpigmentation in associated areas. Head lice most often manifest with localized scalp pruritus and associated excoriation and cervical or occipital lymphadenopathy.³²

Diagnosis—The diagnosis of pediculosis is clinical, with confirmation requiring direct examination of the insect or nits (the egg case of the parasite)(Figure 4). Body lice and associated nits can be visualized on clothing seams near areas of highest body temperature, particularly the waistband. Head lice may be visualized crawling on hair shafts or on a louse comb. Nits are firmly attached to hair shafts and are visible to the naked eye, whereas pseudonits slide freely along the hair shaft and are not a manifestation of louse infestation (Figure 5).³¹

Treatment—Treatment varies by affected area. Pediculosis corporis may be treated with permethrin cream 5% applied to the entire body and left on for 8 to 10 hours, but this may not be necessary if facilities are available to wash and dry clothing.³³ The use of oral ivermectin and permethrin-impregnated underwear both have been proposed.^34,35 Treatment of pediculosis capitis may be accomplished with a variety of topical pediculicides including permethrin, pyrethrum with piperonyl butoxide, dimethicone, malathion, benzyl alcohol, spinosad, and topical ivermectin.²² Topical corticosteroids or emollients may be employed for residual pruritus.

Equally important is environmental elimination of infestation. Clothing should be discarded if possible or washed and dried using high heat. If neither approach is possible or appropriate, clothing may be sealed in a plastic bag for 2 weeks or treated with a pediculicide. Nit combing is an important adjunct in the treatment of pediculosis capitis.³⁶ It is important to encourage return to work and/or school immediately after treatment. “No nit” policies are more harmful to education than helpful for prevention of investation.³⁷

Pediculosis corporis may transmit infectious agents including Bartonella quintana, (trench fever, endocarditis, bacillary angiomatosis), Borrelia recurrentis (louse-borne relapsing fever), and Rickettsia prowazekii (epidemic typhus).^31,38,39 Additionally, severe pediculosis infestations have the potential to cause chronic blood loss in affected populations. In a study of patients with active pediculosis infestation, mean hemoglobin values were found to be 2.5 g/dL lower than a matched population without infestation.⁴⁰ It is important to consider pediculosis as a risk for iron-deficiency anemia in populations who are known to lack access to regular medical evaluation.⁴¹

Future Considerations

Increased access to tools and education for clinicians treating refugee populations is key to reducing the burden of parasitic skin disease and related morbidity and mortality in vulnerable groups both domestically and globally. One such tool, the Skin NTDs App, was launched by the World Health Organization in 2020. It is available for free for Android and iOS devices to assist clinicians in the field with the diagnosis and treatment of neglected tropical diseases—including scabies—that may affect refugee populations.⁴²

Additionally, to both improve access and limit preventable sequelae, future investigations into appropriate models of community-based care are paramount. The model of community-based care is centered on the idea of care provision that prioritizes safety, accessibility, affordability, and acceptability in an environment closest to vulnerable populations. The largest dermatologic society, the International League of Dermatological Societies, formed a Migrant Health Dermatology Working Group that prioritizes understanding and improving care for refugee and migrant populations; this group hosted a summit in 2022, bringing together international subject matter leaders to discuss such models of care and set goals for the creation of tool kits for patients, frontline health care workers, and dermatologists.⁴³

Conclusion

Improvement in dermatologic care of refugee populations includes provision of culturally and linguistically appropriate care by trained clinicians, adequate access to the most essential medications, and basic physical or legal access to health care systems in general.^8,11,44 Parasitic infestations have the potential to remain asymptomatic for extended periods of time and result in spread to potentially nonendemic regions of resettlement.⁴⁵ Additionally, the psychosocial well-being of refugee populations upon resettlement may be negatively affected by stigma of disease processes such as scabies and pediculosis, leading to additional barriers to successful re-entry into the patient’s new environment.⁴⁶ Therefore, proper screening, diagnosis, and treatment of the most common parasitic infestations in this population have great potential to improve outcomes for large groups across the globe.

The Diagnosis: Subcutaneous Fat Necrosis

Histopathology revealed lobular panniculitis with lymphohistiocytic inflammation, lipid crystals, and calcifications in our patient (Figure). Subcutaneous fat necrosis (SCFN) was diagnosed based on these characteristic histopathologic findings. No further treatment was pursued.

Subcutaneous fat necrosis is a rare, self-limiting panniculitis that typically resolves within several weeks to months without scarring. It manifests as red or violaceous subcutaneous nodules or plaques most commonly on the buttocks, trunk, proximal arms and legs, and cheeks.¹ Histopathology reveals lobular panniculitis with dense granulomatous infiltrates of histiocytes, eosinophils, and multinucleated giant cells with needle-shaped crystals. Focal areas of fat necrosis with calcification also can be seen.²

The epidemiology of SCFN is unknown. Most cases occur in healthy full-term to postterm neonates who experience hypoxia, other prenatal stressors, or therapeutic hypothermia for the treatment of hypoxic-ischemic encephalopathy.³ Although the etiology is unclear, certain inciting factors such as local tissue hypoxia, cold exposure, meconium aspiration, maternal diabetes, preeclampsia, and mechanical pressure have been proposed. Our patient underwent hypothermic cooling protocol, and it has been suggested that the increased saturated to unsaturated fat concentration in the skin of newborns increases the melting point, thus predisposing them to fat crystalization.⁴ Cases of SCFN involving the scalp are rare; therefore, any newborns receiving hypothermic therapy for hypoxic-ischemic encephalopathy should have a thorough skin examination with possible biopsy of lesions that are characteristic of SCFN, such as red or violaceous subcutaneous nodules or plaques, for specific disease identification.

The main complication of SCFN is hypercalcemia, which occurs in approximately 50% of cases. Other serum abnormalities include hyperglycemia, hypertriglyceridemia, and thrombocytopenia, though these findings are not as well associated.⁴ Patients with associated hypercalcemia may be asymptomatic, as in our patient, but other presentations include irritability, weakness, anorexia, vomiting, renal failure, failure to thrive, and encephalopathy. Nephrocalcinosis is a common complication of severe hypercalcemia; however, there is little evidence of associated major renal dysfunction.⁵ The exact mechanism of hypercalcemia is poorly understood. A widely accepted theory postulates that a granulomatous inflammatory infiltrate upregulates 1-α-hydroxylase activity, which enzymatically converts 25-hydroxyvitamin D to its active form, 1,25-dihydroxycholecalciferol, which increases bone resorption and calcium absorption through the gastrointestinal tract and renal systems. Treatments for hypercalcemia include hyperhydration, calcium-wasting diuretics, and low calcium intake.⁶ Furthermore, calcium levels should be obtained at the time of diagnosis and 30, 45, and 60 days after the lesions resolve.⁴

Subcutaneous fat necrosis needs to be differentiated from the more severe panniculitis, sclerema neonatorum (SN), which typically affects critically ill, preterm, and small-for-gestational-age newborns. It is associated with a high mortality rate and is characterized by skin and subadjacent tissue structures. The process typically begins in the thighs, buttocks, or trunk and spreads diffusely, sparing the fat-free palms, soles, and genitalia.⁷ Although our patient was born preterm, the physical characteristics of the nodule and the lack of severe illness placed SN lower on our differential. Histopathologic differences between SCFN and SN involve the extent of tissue fibrosis and presence of inflammatory cells. Sclerema neonatorum typically manifests with thickened connective tissue with a sparse inflammatory infiltrate, including lymphocytes, histiocytes, and multinucleated giant cells.⁷ Conversely, SCFN manifests with fat necrosis with an extensive inflammatory infiltrate. It is important to be able to distinguish between these 2 conditions, as both have vastly different prognoses.

Cold panniculitis, sometimes called “popsicle panniculitis,” is a phenomenon in which cold contact with the skin causes eruption of firm, erythematous, indurated plaques at the site of exposure. This self-limiting condition typically appears hours to days after cold exposure and spontaneously resolves in a few weeks.⁸ Therapeutic hypothermic protocol treatment involves using cooling devices to lower the body temperature for a short duration. The temperature typically is lowered to approximately 32 °C to 36 °C. These temperatures are not low enough to induce cold panniculitis, which is more commonly seen in facial ice applications when managing supraventricular tachycardia in neonates.

Cephalohematoma is a birthing injury that causes blood accumulation within the subperiosteal space. During parturition, the compressive and sheering forces on the calvarium rupture the vessels passing through the periosteum, causing blood to pool slowly into the subperiostium; thus, a cephalohematoma usually manifests later at 1 to 3 days of life as localized head swelling.⁹ The bleeding typically does not cross suture lines and is primarily found in the occipital or parietal regions. The incidence has been reported to be 0.4% to 2.5% of all live births.¹⁰ Although the location of the nodule in our patient was in the occipital region, imaging and biopsy results did not show hemorrhagic findings consistent with cephalohematoma. Management of cephalohematoma mainly is observational, as the mass slowly regresses and the accumulated blood gradually is reabsorbed.

Fungal scalp infections (tinea capitis) are common in the pediatric population. The peak incidence of this infection has been reported in children aged 3 to 7 years, with Trichophyton tonsurans and Microsporum canis as the usual causative organisms.¹¹ Clinical features of tinea capitis include scaly patches with hair loss, hair loss with black pigmented dots at the follicular openings, diffuse scalp scaling with subtle hair loss, and cervical lymphadenopathy.¹² Although less common, tinea capitis can progress to a more severe form known as a kerion, which is characterized by a tender plaque with pustules and crusting. A kerion can result in permanent scarring and alopecia if left untreated.¹² In our patient, a nodule with scaling and faint erythema was observed, but no black pigmented dots at the follicular orifices were present. Therefore, a potassium hydroxide wet mount preparation used to diagnose tinea capitis was unnecessary. Systemic oral antifungal therapy such as fluconazole or terbinafine is the standard treatment for tinea capitis.

The Diagnosis: Subcutaneous Fat Necrosis

Histopathology revealed lobular panniculitis with lymphohistiocytic inflammation, lipid crystals, and calcifications in our patient (Figure). Subcutaneous fat necrosis (SCFN) was diagnosed based on these characteristic histopathologic findings. No further treatment was pursued.

Subcutaneous fat necrosis is a rare, self-limiting panniculitis that typically resolves within several weeks to months without scarring. It manifests as red or violaceous subcutaneous nodules or plaques most commonly on the buttocks, trunk, proximal arms and legs, and cheeks.¹ Histopathology reveals lobular panniculitis with dense granulomatous infiltrates of histiocytes, eosinophils, and multinucleated giant cells with needle-shaped crystals. Focal areas of fat necrosis with calcification also can be seen.²

The epidemiology of SCFN is unknown. Most cases occur in healthy full-term to postterm neonates who experience hypoxia, other prenatal stressors, or therapeutic hypothermia for the treatment of hypoxic-ischemic encephalopathy.³ Although the etiology is unclear, certain inciting factors such as local tissue hypoxia, cold exposure, meconium aspiration, maternal diabetes, preeclampsia, and mechanical pressure have been proposed. Our patient underwent hypothermic cooling protocol, and it has been suggested that the increased saturated to unsaturated fat concentration in the skin of newborns increases the melting point, thus predisposing them to fat crystalization.⁴ Cases of SCFN involving the scalp are rare; therefore, any newborns receiving hypothermic therapy for hypoxic-ischemic encephalopathy should have a thorough skin examination with possible biopsy of lesions that are characteristic of SCFN, such as red or violaceous subcutaneous nodules or plaques, for specific disease identification.

The main complication of SCFN is hypercalcemia, which occurs in approximately 50% of cases. Other serum abnormalities include hyperglycemia, hypertriglyceridemia, and thrombocytopenia, though these findings are not as well associated.⁴ Patients with associated hypercalcemia may be asymptomatic, as in our patient, but other presentations include irritability, weakness, anorexia, vomiting, renal failure, failure to thrive, and encephalopathy. Nephrocalcinosis is a common complication of severe hypercalcemia; however, there is little evidence of associated major renal dysfunction.⁵ The exact mechanism of hypercalcemia is poorly understood. A widely accepted theory postulates that a granulomatous inflammatory infiltrate upregulates 1-α-hydroxylase activity, which enzymatically converts 25-hydroxyvitamin D to its active form, 1,25-dihydroxycholecalciferol, which increases bone resorption and calcium absorption through the gastrointestinal tract and renal systems. Treatments for hypercalcemia include hyperhydration, calcium-wasting diuretics, and low calcium intake.⁶ Furthermore, calcium levels should be obtained at the time of diagnosis and 30, 45, and 60 days after the lesions resolve.⁴

Subcutaneous fat necrosis needs to be differentiated from the more severe panniculitis, sclerema neonatorum (SN), which typically affects critically ill, preterm, and small-for-gestational-age newborns. It is associated with a high mortality rate and is characterized by skin and subadjacent tissue structures. The process typically begins in the thighs, buttocks, or trunk and spreads diffusely, sparing the fat-free palms, soles, and genitalia.⁷ Although our patient was born preterm, the physical characteristics of the nodule and the lack of severe illness placed SN lower on our differential. Histopathologic differences between SCFN and SN involve the extent of tissue fibrosis and presence of inflammatory cells. Sclerema neonatorum typically manifests with thickened connective tissue with a sparse inflammatory infiltrate, including lymphocytes, histiocytes, and multinucleated giant cells.⁷ Conversely, SCFN manifests with fat necrosis with an extensive inflammatory infiltrate. It is important to be able to distinguish between these 2 conditions, as both have vastly different prognoses.

Cold panniculitis, sometimes called “popsicle panniculitis,” is a phenomenon in which cold contact with the skin causes eruption of firm, erythematous, indurated plaques at the site of exposure. This self-limiting condition typically appears hours to days after cold exposure and spontaneously resolves in a few weeks.⁸ Therapeutic hypothermic protocol treatment involves using cooling devices to lower the body temperature for a short duration. The temperature typically is lowered to approximately 32 °C to 36 °C. These temperatures are not low enough to induce cold panniculitis, which is more commonly seen in facial ice applications when managing supraventricular tachycardia in neonates.

Cephalohematoma is a birthing injury that causes blood accumulation within the subperiosteal space. During parturition, the compressive and sheering forces on the calvarium rupture the vessels passing through the periosteum, causing blood to pool slowly into the subperiostium; thus, a cephalohematoma usually manifests later at 1 to 3 days of life as localized head swelling.⁹ The bleeding typically does not cross suture lines and is primarily found in the occipital or parietal regions. The incidence has been reported to be 0.4% to 2.5% of all live births.¹⁰ Although the location of the nodule in our patient was in the occipital region, imaging and biopsy results did not show hemorrhagic findings consistent with cephalohematoma. Management of cephalohematoma mainly is observational, as the mass slowly regresses and the accumulated blood gradually is reabsorbed.

Fungal scalp infections (tinea capitis) are common in the pediatric population. The peak incidence of this infection has been reported in children aged 3 to 7 years, with Trichophyton tonsurans and Microsporum canis as the usual causative organisms.¹¹ Clinical features of tinea capitis include scaly patches with hair loss, hair loss with black pigmented dots at the follicular openings, diffuse scalp scaling with subtle hair loss, and cervical lymphadenopathy.¹² Although less common, tinea capitis can progress to a more severe form known as a kerion, which is characterized by a tender plaque with pustules and crusting. A kerion can result in permanent scarring and alopecia if left untreated.¹² In our patient, a nodule with scaling and faint erythema was observed, but no black pigmented dots at the follicular orifices were present. Therefore, a potassium hydroxide wet mount preparation used to diagnose tinea capitis was unnecessary. Systemic oral antifungal therapy such as fluconazole or terbinafine is the standard treatment for tinea capitis.

The Diagnosis: Subcutaneous Fat Necrosis

Histopathology revealed lobular panniculitis with lymphohistiocytic inflammation, lipid crystals, and calcifications in our patient (Figure). Subcutaneous fat necrosis (SCFN) was diagnosed based on these characteristic histopathologic findings. No further treatment was pursued.

Subcutaneous fat necrosis is a rare, self-limiting panniculitis that typically resolves within several weeks to months without scarring. It manifests as red or violaceous subcutaneous nodules or plaques most commonly on the buttocks, trunk, proximal arms and legs, and cheeks.¹ Histopathology reveals lobular panniculitis with dense granulomatous infiltrates of histiocytes, eosinophils, and multinucleated giant cells with needle-shaped crystals. Focal areas of fat necrosis with calcification also can be seen.²

The epidemiology of SCFN is unknown. Most cases occur in healthy full-term to postterm neonates who experience hypoxia, other prenatal stressors, or therapeutic hypothermia for the treatment of hypoxic-ischemic encephalopathy.³ Although the etiology is unclear, certain inciting factors such as local tissue hypoxia, cold exposure, meconium aspiration, maternal diabetes, preeclampsia, and mechanical pressure have been proposed. Our patient underwent hypothermic cooling protocol, and it has been suggested that the increased saturated to unsaturated fat concentration in the skin of newborns increases the melting point, thus predisposing them to fat crystalization.⁴ Cases of SCFN involving the scalp are rare; therefore, any newborns receiving hypothermic therapy for hypoxic-ischemic encephalopathy should have a thorough skin examination with possible biopsy of lesions that are characteristic of SCFN, such as red or violaceous subcutaneous nodules or plaques, for specific disease identification.

The main complication of SCFN is hypercalcemia, which occurs in approximately 50% of cases. Other serum abnormalities include hyperglycemia, hypertriglyceridemia, and thrombocytopenia, though these findings are not as well associated.⁴ Patients with associated hypercalcemia may be asymptomatic, as in our patient, but other presentations include irritability, weakness, anorexia, vomiting, renal failure, failure to thrive, and encephalopathy. Nephrocalcinosis is a common complication of severe hypercalcemia; however, there is little evidence of associated major renal dysfunction.⁵ The exact mechanism of hypercalcemia is poorly understood. A widely accepted theory postulates that a granulomatous inflammatory infiltrate upregulates 1-α-hydroxylase activity, which enzymatically converts 25-hydroxyvitamin D to its active form, 1,25-dihydroxycholecalciferol, which increases bone resorption and calcium absorption through the gastrointestinal tract and renal systems. Treatments for hypercalcemia include hyperhydration, calcium-wasting diuretics, and low calcium intake.⁶ Furthermore, calcium levels should be obtained at the time of diagnosis and 30, 45, and 60 days after the lesions resolve.⁴

Subcutaneous fat necrosis needs to be differentiated from the more severe panniculitis, sclerema neonatorum (SN), which typically affects critically ill, preterm, and small-for-gestational-age newborns. It is associated with a high mortality rate and is characterized by skin and subadjacent tissue structures. The process typically begins in the thighs, buttocks, or trunk and spreads diffusely, sparing the fat-free palms, soles, and genitalia.⁷ Although our patient was born preterm, the physical characteristics of the nodule and the lack of severe illness placed SN lower on our differential. Histopathologic differences between SCFN and SN involve the extent of tissue fibrosis and presence of inflammatory cells. Sclerema neonatorum typically manifests with thickened connective tissue with a sparse inflammatory infiltrate, including lymphocytes, histiocytes, and multinucleated giant cells.⁷ Conversely, SCFN manifests with fat necrosis with an extensive inflammatory infiltrate. It is important to be able to distinguish between these 2 conditions, as both have vastly different prognoses.

Cold panniculitis, sometimes called “popsicle panniculitis,” is a phenomenon in which cold contact with the skin causes eruption of firm, erythematous, indurated plaques at the site of exposure. This self-limiting condition typically appears hours to days after cold exposure and spontaneously resolves in a few weeks.⁸ Therapeutic hypothermic protocol treatment involves using cooling devices to lower the body temperature for a short duration. The temperature typically is lowered to approximately 32 °C to 36 °C. These temperatures are not low enough to induce cold panniculitis, which is more commonly seen in facial ice applications when managing supraventricular tachycardia in neonates.

Cephalohematoma is a birthing injury that causes blood accumulation within the subperiosteal space. During parturition, the compressive and sheering forces on the calvarium rupture the vessels passing through the periosteum, causing blood to pool slowly into the subperiostium; thus, a cephalohematoma usually manifests later at 1 to 3 days of life as localized head swelling.⁹ The bleeding typically does not cross suture lines and is primarily found in the occipital or parietal regions. The incidence has been reported to be 0.4% to 2.5% of all live births.¹⁰ Although the location of the nodule in our patient was in the occipital region, imaging and biopsy results did not show hemorrhagic findings consistent with cephalohematoma. Management of cephalohematoma mainly is observational, as the mass slowly regresses and the accumulated blood gradually is reabsorbed.

Fungal scalp infections (tinea capitis) are common in the pediatric population. The peak incidence of this infection has been reported in children aged 3 to 7 years, with Trichophyton tonsurans and Microsporum canis as the usual causative organisms.¹¹ Clinical features of tinea capitis include scaly patches with hair loss, hair loss with black pigmented dots at the follicular openings, diffuse scalp scaling with subtle hair loss, and cervical lymphadenopathy.¹² Although less common, tinea capitis can progress to a more severe form known as a kerion, which is characterized by a tender plaque with pustules and crusting. A kerion can result in permanent scarring and alopecia if left untreated.¹² In our patient, a nodule with scaling and faint erythema was observed, but no black pigmented dots at the follicular orifices were present. Therefore, a potassium hydroxide wet mount preparation used to diagnose tinea capitis was unnecessary. Systemic oral antifungal therapy such as fluconazole or terbinafine is the standard treatment for tinea capitis.

The Diagnosis: Erythrodermic Allergic Contact Dermatitis

The worsening symptoms in our patient prompted intervention rather than observation and reassurance. Contact allergy to lanolin was suspected given the worsening presentation after the addition of Minerin, which was immediately discontinued. The patient’s family applied betamethasone cream 0.1% twice daily to severe plaques, pimecrolimus cream 1% to the face, and triamcinolone cream 0.1% to the rest of the body. At follow-up 1 week later, he experienced complete resolution of symptoms, which supported the diagnosis of erythrodermic allergic contact dermatitis (ACD).

The prevalence of ACD caused by lanolin varies among the general population from 1.2% to 6.9%.¹ Lanolin recently was named Allergen of the Year in 2023 by the American Contact Dermatitis Society.² It can be found in various commercial products, including creams, soaps, and ointments. Atopic dermatitis (AD) is a common pediatric inflammatory skin disorder that typically is treated with these products.³ In a study analyzing 533 products, up to 6% of skin care products for babies and children contained lanolin.⁴ Therefore, exposure to lanolin-containing products may be fairly common in the pediatric population.

Lanolin is a fatlike substance derived from sheep sebaceous gland secretions and extracted from sheep’s wool. Its composition varies by sheep breed, location, and extraction and purification methods. The most common allergens involve the alcoholic fraction produced by hydrolysis of lanolin.⁴ In 1996, Wolf⁵ described the “lanolin paradox,” which argued the difficulty with identifying lanolin as an allergen (similar to Fisher’s “paraben paradox”) based on 4 principles: (1) lanolin-containing topical medicaments tend to be more sensitizing than lanolin-containing cosmetics; (2) patients with ACD after applying lanolin-containing topical medicaments to damaged or ulcerated skin often can apply lanolin-containing cosmetics to normal or unaffected skin without a reaction; (3) false-negative patch test results often occur in lanolin-sensitive patients; and (4) patch testing with a single lanolin-containing agent (lanolin alcohol [30% in petrolatum]) is an unreliable and inadequate method of detecting lanolin allergy.^6,7 This theory elucidates the challenge of diagnosing contact allergies, particularly lanolin contact allergies.

Clinical features of acute ACD vary by skin type. Lighter skin types may have well-demarcated, pruritic, eczematous patches and plaques affecting the flexor surfaces. Asian patients may present with psoriasiform plaques with more well-demarcated borders and increased scaling and lichenification. In patients with darker skin types, dermatitis may manifest as papulation, lichenification, and color changes (violet, gray, or darker brown) along extensor surfaces.8 Chronic dermatitis manifests as lichenified scaly plaques. Given the diversity in dermatitis manifestation and the challenges of identifying erythema, especially in skin of color, clinicians may misidentify disease severity. These features aid in diagnosing and treating patients presenting with diffuse erythroderma and worsening eczematous patches and plaques despite use of typical topical treatments.

The differential diagnosis includes irritant contact dermatitis, AD, seborrheic dermatitis, and chronic plaque psoriasis. Negative patch testing suggests contact dermatitis based on exposure to a product. A thorough medication and personal history helps distinguish ACD from AD. Atopic dermatitis classically appears on the flexural areas, face, eyelids, and hands of patients with a personal or family history of atopy. Greasy scaly plaques on the central part of the face, eyelids, and scalp commonly are found in seborrheic dermatitis. In chronic plaque psoriasis, lesions typically are described as welldemarcated, inflamed plaques with notable scale located primarily in the scalp and diaper area in newborns and children until the age of 2 years. Our patient presented with scaly plaques throughout most of the body. The history of Minerin use over the course of 3 to 5 months and worsening skin eruptions involving a majority of the skin surface suggested continued exposure.

Patch testing assists in the diagnosis of ACD, with varying results due to manufacturing and processing inconsistencies in the composition of various substances used in the standard test sets, often making it difficult to diagnose lanolin as an allergen. According to Lee and Warshaw,6 the lack of uniformity within testing of lanolin-containing products may cause false-positive results, poor patch-test reproducibility, and loss of allergic contact response. A 2019 study utilized a combination of Amerchol L101 and lanolin alcohol to improve the diagnosis of lanolin allergy, as standard testing may not identify patients with lanolin sensitivities.1 A study with the North American Contact Dermatitis Group from 2005 to 2012 demonstrated that positive patch testing among children was the most consistent method for diagnosing ACD, and results were clinically relevant.⁹ However, the different lanolin-containing products are not standardized in patch testing, which often causes mixed reactions and does not definitely demonstrate classic positive results, even with the use of repeated open application tests.² Although there has been an emphasis on refining the standardization of the lanolin used for patch testing, lanolin contact allergy remains a predominantly clinical diagnosis.

Both AD and ACD are common pediatric skin findings, and mixed positive and neutral associations between AD and allergy to lanolin have been described in a few studies.^1,3,9,10 A history of atopy is more notable in a pediatric patient vs an adult, as sensitivities tend to subside into adulthood.⁹ Further studies and more precise testing are needed to investigate the relationship between AD and ACD.

The Diagnosis: Erythrodermic Allergic Contact Dermatitis

The worsening symptoms in our patient prompted intervention rather than observation and reassurance. Contact allergy to lanolin was suspected given the worsening presentation after the addition of Minerin, which was immediately discontinued. The patient’s family applied betamethasone cream 0.1% twice daily to severe plaques, pimecrolimus cream 1% to the face, and triamcinolone cream 0.1% to the rest of the body. At follow-up 1 week later, he experienced complete resolution of symptoms, which supported the diagnosis of erythrodermic allergic contact dermatitis (ACD).

The prevalence of ACD caused by lanolin varies among the general population from 1.2% to 6.9%.¹ Lanolin recently was named Allergen of the Year in 2023 by the American Contact Dermatitis Society.² It can be found in various commercial products, including creams, soaps, and ointments. Atopic dermatitis (AD) is a common pediatric inflammatory skin disorder that typically is treated with these products.³ In a study analyzing 533 products, up to 6% of skin care products for babies and children contained lanolin.⁴ Therefore, exposure to lanolin-containing products may be fairly common in the pediatric population.

Lanolin is a fatlike substance derived from sheep sebaceous gland secretions and extracted from sheep’s wool. Its composition varies by sheep breed, location, and extraction and purification methods. The most common allergens involve the alcoholic fraction produced by hydrolysis of lanolin.⁴ In 1996, Wolf⁵ described the “lanolin paradox,” which argued the difficulty with identifying lanolin as an allergen (similar to Fisher’s “paraben paradox”) based on 4 principles: (1) lanolin-containing topical medicaments tend to be more sensitizing than lanolin-containing cosmetics; (2) patients with ACD after applying lanolin-containing topical medicaments to damaged or ulcerated skin often can apply lanolin-containing cosmetics to normal or unaffected skin without a reaction; (3) false-negative patch test results often occur in lanolin-sensitive patients; and (4) patch testing with a single lanolin-containing agent (lanolin alcohol [30% in petrolatum]) is an unreliable and inadequate method of detecting lanolin allergy.^6,7 This theory elucidates the challenge of diagnosing contact allergies, particularly lanolin contact allergies.

Clinical features of acute ACD vary by skin type. Lighter skin types may have well-demarcated, pruritic, eczematous patches and plaques affecting the flexor surfaces. Asian patients may present with psoriasiform plaques with more well-demarcated borders and increased scaling and lichenification. In patients with darker skin types, dermatitis may manifest as papulation, lichenification, and color changes (violet, gray, or darker brown) along extensor surfaces.8 Chronic dermatitis manifests as lichenified scaly plaques. Given the diversity in dermatitis manifestation and the challenges of identifying erythema, especially in skin of color, clinicians may misidentify disease severity. These features aid in diagnosing and treating patients presenting with diffuse erythroderma and worsening eczematous patches and plaques despite use of typical topical treatments.

The differential diagnosis includes irritant contact dermatitis, AD, seborrheic dermatitis, and chronic plaque psoriasis. Negative patch testing suggests contact dermatitis based on exposure to a product. A thorough medication and personal history helps distinguish ACD from AD. Atopic dermatitis classically appears on the flexural areas, face, eyelids, and hands of patients with a personal or family history of atopy. Greasy scaly plaques on the central part of the face, eyelids, and scalp commonly are found in seborrheic dermatitis. In chronic plaque psoriasis, lesions typically are described as welldemarcated, inflamed plaques with notable scale located primarily in the scalp and diaper area in newborns and children until the age of 2 years. Our patient presented with scaly plaques throughout most of the body. The history of Minerin use over the course of 3 to 5 months and worsening skin eruptions involving a majority of the skin surface suggested continued exposure.

Patch testing assists in the diagnosis of ACD, with varying results due to manufacturing and processing inconsistencies in the composition of various substances used in the standard test sets, often making it difficult to diagnose lanolin as an allergen. According to Lee and Warshaw,6 the lack of uniformity within testing of lanolin-containing products may cause false-positive results, poor patch-test reproducibility, and loss of allergic contact response. A 2019 study utilized a combination of Amerchol L101 and lanolin alcohol to improve the diagnosis of lanolin allergy, as standard testing may not identify patients with lanolin sensitivities.1 A study with the North American Contact Dermatitis Group from 2005 to 2012 demonstrated that positive patch testing among children was the most consistent method for diagnosing ACD, and results were clinically relevant.⁹ However, the different lanolin-containing products are not standardized in patch testing, which often causes mixed reactions and does not definitely demonstrate classic positive results, even with the use of repeated open application tests.² Although there has been an emphasis on refining the standardization of the lanolin used for patch testing, lanolin contact allergy remains a predominantly clinical diagnosis.

Both AD and ACD are common pediatric skin findings, and mixed positive and neutral associations between AD and allergy to lanolin have been described in a few studies.^1,3,9,10 A history of atopy is more notable in a pediatric patient vs an adult, as sensitivities tend to subside into adulthood.⁹ Further studies and more precise testing are needed to investigate the relationship between AD and ACD.

The Diagnosis: Erythrodermic Allergic Contact Dermatitis

The worsening symptoms in our patient prompted intervention rather than observation and reassurance. Contact allergy to lanolin was suspected given the worsening presentation after the addition of Minerin, which was immediately discontinued. The patient’s family applied betamethasone cream 0.1% twice daily to severe plaques, pimecrolimus cream 1% to the face, and triamcinolone cream 0.1% to the rest of the body. At follow-up 1 week later, he experienced complete resolution of symptoms, which supported the diagnosis of erythrodermic allergic contact dermatitis (ACD).

The prevalence of ACD caused by lanolin varies among the general population from 1.2% to 6.9%.¹ Lanolin recently was named Allergen of the Year in 2023 by the American Contact Dermatitis Society.² It can be found in various commercial products, including creams, soaps, and ointments. Atopic dermatitis (AD) is a common pediatric inflammatory skin disorder that typically is treated with these products.³ In a study analyzing 533 products, up to 6% of skin care products for babies and children contained lanolin.⁴ Therefore, exposure to lanolin-containing products may be fairly common in the pediatric population.

Lanolin is a fatlike substance derived from sheep sebaceous gland secretions and extracted from sheep’s wool. Its composition varies by sheep breed, location, and extraction and purification methods. The most common allergens involve the alcoholic fraction produced by hydrolysis of lanolin.⁴ In 1996, Wolf⁵ described the “lanolin paradox,” which argued the difficulty with identifying lanolin as an allergen (similar to Fisher’s “paraben paradox”) based on 4 principles: (1) lanolin-containing topical medicaments tend to be more sensitizing than lanolin-containing cosmetics; (2) patients with ACD after applying lanolin-containing topical medicaments to damaged or ulcerated skin often can apply lanolin-containing cosmetics to normal or unaffected skin without a reaction; (3) false-negative patch test results often occur in lanolin-sensitive patients; and (4) patch testing with a single lanolin-containing agent (lanolin alcohol [30% in petrolatum]) is an unreliable and inadequate method of detecting lanolin allergy.^6,7 This theory elucidates the challenge of diagnosing contact allergies, particularly lanolin contact allergies.

Clinical features of acute ACD vary by skin type. Lighter skin types may have well-demarcated, pruritic, eczematous patches and plaques affecting the flexor surfaces. Asian patients may present with psoriasiform plaques with more well-demarcated borders and increased scaling and lichenification. In patients with darker skin types, dermatitis may manifest as papulation, lichenification, and color changes (violet, gray, or darker brown) along extensor surfaces.8 Chronic dermatitis manifests as lichenified scaly plaques. Given the diversity in dermatitis manifestation and the challenges of identifying erythema, especially in skin of color, clinicians may misidentify disease severity. These features aid in diagnosing and treating patients presenting with diffuse erythroderma and worsening eczematous patches and plaques despite use of typical topical treatments.

The differential diagnosis includes irritant contact dermatitis, AD, seborrheic dermatitis, and chronic plaque psoriasis. Negative patch testing suggests contact dermatitis based on exposure to a product. A thorough medication and personal history helps distinguish ACD from AD. Atopic dermatitis classically appears on the flexural areas, face, eyelids, and hands of patients with a personal or family history of atopy. Greasy scaly plaques on the central part of the face, eyelids, and scalp commonly are found in seborrheic dermatitis. In chronic plaque psoriasis, lesions typically are described as welldemarcated, inflamed plaques with notable scale located primarily in the scalp and diaper area in newborns and children until the age of 2 years. Our patient presented with scaly plaques throughout most of the body. The history of Minerin use over the course of 3 to 5 months and worsening skin eruptions involving a majority of the skin surface suggested continued exposure.

Patch testing assists in the diagnosis of ACD, with varying results due to manufacturing and processing inconsistencies in the composition of various substances used in the standard test sets, often making it difficult to diagnose lanolin as an allergen. According to Lee and Warshaw,6 the lack of uniformity within testing of lanolin-containing products may cause false-positive results, poor patch-test reproducibility, and loss of allergic contact response. A 2019 study utilized a combination of Amerchol L101 and lanolin alcohol to improve the diagnosis of lanolin allergy, as standard testing may not identify patients with lanolin sensitivities.1 A study with the North American Contact Dermatitis Group from 2005 to 2012 demonstrated that positive patch testing among children was the most consistent method for diagnosing ACD, and results were clinically relevant.⁹ However, the different lanolin-containing products are not standardized in patch testing, which often causes mixed reactions and does not definitely demonstrate classic positive results, even with the use of repeated open application tests.² Although there has been an emphasis on refining the standardization of the lanolin used for patch testing, lanolin contact allergy remains a predominantly clinical diagnosis.

Both AD and ACD are common pediatric skin findings, and mixed positive and neutral associations between AD and allergy to lanolin have been described in a few studies.^1,3,9,10 A history of atopy is more notable in a pediatric patient vs an adult, as sensitivities tend to subside into adulthood.⁹ Further studies and more precise testing are needed to investigate the relationship between AD and ACD.

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The Diagnosis: Hypertrophic Lichen Planus

Two biopsies from the left lateral foot revealed hyperkeratosis, wedge-shaped hypergranulosis, irregular acanthosis, and a bandlike lymphocytic infiltrate in the superficial dermis with a classic sawtooth pattern of the rete ridges (Figure 1). Based on the clinical findings and histopathology, the patient was diagnosed with hypertrophic lichen planus (LP) and was treated with clobetasol ointment 0.05%, which resulted in progression of the symptoms. She experienced notable improvement 3 months after adding methotrexate 12.5 mg weekly (Figure 2).

Lichen planus is an idiopathic chronic inflammatory condition of the skin and mucous membranes that classically manifests as pruritic violaceous papules and plaques, which commonly are found on the wrists, lower back, and ankles.¹ The most common variants of LP are hypertrophic, linear, mucosal, actinic, follicular, pigmented, annular, atrophic, and guttate.² The clinical presentation and biopsy results in our patient were consistent with the hypertrophic variant of LP, which is a chronic condition that most often manifests on the lower legs, especially around the ankles, as hyperkeratotic papules, plaques, and nodules.^2,3 The exact pathophysiology of hypertrophic LP is unknown, but there is evidence that the immune system plays a role in its development and that the Koebner phenomenon may contribute to its exacerbation.⁴ There is a well-known association between LP and hepatitis. Patients with chronic LP may develop squamous cell carcinoma.⁴ The variants of LP can overlap and do not exist independent of one another. Recognizing the overlap in these variants allows for earlier diagnosis and therapeutic intervention of the disease process to limit disease progression and patient clinic visits and to improve patient quality of life.

The differential diagnosis for hyperkeratotic plaques of the feet and ankles can be broad and may include keratosis lichenoides chronica, palmoplantar keratoderma, palmoplantar psoriasis, or lichen amyloidosis. These conditions are classified based on various criteria that include extent of disease manifestations, morphology of palmoplantar skin involvement, inheritance patterns, and molecular pathogenesis.⁵ Keratosis lichenoides chronica is a rare dermatosis that presents as a distinctive seborrheic dermatitis–like facial eruption. The facial eruption is accompanied by violaceous papular and nodular lesions that appear on the extremities and trunk, typically arranged in a linear or reticular pattern.⁶ Palmoplantar keratoderma represents a group of acquired and hereditary conditions that are characterized by excessive thickening of the palms and soles.⁵ Palmoplantar psoriasis is a variant of psoriasis that affects the palms and soles and can manifest as hyperkeratosis, pustular, or mixed morphology.⁷ Lichen amyloidosis is a subtype of primary localized cutaneous amyloidosis that manifests as multiple pruritic, firm, hyperpigmented, hyperkeratotic papules on the shins that later coalesce in a rippled pattern.^8,9

The first-line treatment for hypertrophic LP is topical corticosteroids. Alternative therapies include mycophenolate mofetil, acitretin, and intralesional corticosteroid injections.⁴ Treatment is similar for all of the LP variants.

The Diagnosis: Hypertrophic Lichen Planus

Two biopsies from the left lateral foot revealed hyperkeratosis, wedge-shaped hypergranulosis, irregular acanthosis, and a bandlike lymphocytic infiltrate in the superficial dermis with a classic sawtooth pattern of the rete ridges (Figure 1). Based on the clinical findings and histopathology, the patient was diagnosed with hypertrophic lichen planus (LP) and was treated with clobetasol ointment 0.05%, which resulted in progression of the symptoms. She experienced notable improvement 3 months after adding methotrexate 12.5 mg weekly (Figure 2).

Lichen planus is an idiopathic chronic inflammatory condition of the skin and mucous membranes that classically manifests as pruritic violaceous papules and plaques, which commonly are found on the wrists, lower back, and ankles.¹ The most common variants of LP are hypertrophic, linear, mucosal, actinic, follicular, pigmented, annular, atrophic, and guttate.² The clinical presentation and biopsy results in our patient were consistent with the hypertrophic variant of LP, which is a chronic condition that most often manifests on the lower legs, especially around the ankles, as hyperkeratotic papules, plaques, and nodules.^2,3 The exact pathophysiology of hypertrophic LP is unknown, but there is evidence that the immune system plays a role in its development and that the Koebner phenomenon may contribute to its exacerbation.⁴ There is a well-known association between LP and hepatitis. Patients with chronic LP may develop squamous cell carcinoma.⁴ The variants of LP can overlap and do not exist independent of one another. Recognizing the overlap in these variants allows for earlier diagnosis and therapeutic intervention of the disease process to limit disease progression and patient clinic visits and to improve patient quality of life.

The differential diagnosis for hyperkeratotic plaques of the feet and ankles can be broad and may include keratosis lichenoides chronica, palmoplantar keratoderma, palmoplantar psoriasis, or lichen amyloidosis. These conditions are classified based on various criteria that include extent of disease manifestations, morphology of palmoplantar skin involvement, inheritance patterns, and molecular pathogenesis.⁵ Keratosis lichenoides chronica is a rare dermatosis that presents as a distinctive seborrheic dermatitis–like facial eruption. The facial eruption is accompanied by violaceous papular and nodular lesions that appear on the extremities and trunk, typically arranged in a linear or reticular pattern.⁶ Palmoplantar keratoderma represents a group of acquired and hereditary conditions that are characterized by excessive thickening of the palms and soles.⁵ Palmoplantar psoriasis is a variant of psoriasis that affects the palms and soles and can manifest as hyperkeratosis, pustular, or mixed morphology.⁷ Lichen amyloidosis is a subtype of primary localized cutaneous amyloidosis that manifests as multiple pruritic, firm, hyperpigmented, hyperkeratotic papules on the shins that later coalesce in a rippled pattern.^8,9

The first-line treatment for hypertrophic LP is topical corticosteroids. Alternative therapies include mycophenolate mofetil, acitretin, and intralesional corticosteroid injections.⁴ Treatment is similar for all of the LP variants.

The Diagnosis: Hypertrophic Lichen Planus

Two biopsies from the left lateral foot revealed hyperkeratosis, wedge-shaped hypergranulosis, irregular acanthosis, and a bandlike lymphocytic infiltrate in the superficial dermis with a classic sawtooth pattern of the rete ridges (Figure 1). Based on the clinical findings and histopathology, the patient was diagnosed with hypertrophic lichen planus (LP) and was treated with clobetasol ointment 0.05%, which resulted in progression of the symptoms. She experienced notable improvement 3 months after adding methotrexate 12.5 mg weekly (Figure 2).

Lichen planus is an idiopathic chronic inflammatory condition of the skin and mucous membranes that classically manifests as pruritic violaceous papules and plaques, which commonly are found on the wrists, lower back, and ankles.¹ The most common variants of LP are hypertrophic, linear, mucosal, actinic, follicular, pigmented, annular, atrophic, and guttate.² The clinical presentation and biopsy results in our patient were consistent with the hypertrophic variant of LP, which is a chronic condition that most often manifests on the lower legs, especially around the ankles, as hyperkeratotic papules, plaques, and nodules.^2,3 The exact pathophysiology of hypertrophic LP is unknown, but there is evidence that the immune system plays a role in its development and that the Koebner phenomenon may contribute to its exacerbation.⁴ There is a well-known association between LP and hepatitis. Patients with chronic LP may develop squamous cell carcinoma.⁴ The variants of LP can overlap and do not exist independent of one another. Recognizing the overlap in these variants allows for earlier diagnosis and therapeutic intervention of the disease process to limit disease progression and patient clinic visits and to improve patient quality of life.

The differential diagnosis for hyperkeratotic plaques of the feet and ankles can be broad and may include keratosis lichenoides chronica, palmoplantar keratoderma, palmoplantar psoriasis, or lichen amyloidosis. These conditions are classified based on various criteria that include extent of disease manifestations, morphology of palmoplantar skin involvement, inheritance patterns, and molecular pathogenesis.⁵ Keratosis lichenoides chronica is a rare dermatosis that presents as a distinctive seborrheic dermatitis–like facial eruption. The facial eruption is accompanied by violaceous papular and nodular lesions that appear on the extremities and trunk, typically arranged in a linear or reticular pattern.⁶ Palmoplantar keratoderma represents a group of acquired and hereditary conditions that are characterized by excessive thickening of the palms and soles.⁵ Palmoplantar psoriasis is a variant of psoriasis that affects the palms and soles and can manifest as hyperkeratosis, pustular, or mixed morphology.⁷ Lichen amyloidosis is a subtype of primary localized cutaneous amyloidosis that manifests as multiple pruritic, firm, hyperpigmented, hyperkeratotic papules on the shins that later coalesce in a rippled pattern.^8,9

The first-line treatment for hypertrophic LP is topical corticosteroids. Alternative therapies include mycophenolate mofetil, acitretin, and intralesional corticosteroid injections.⁴ Treatment is similar for all of the LP variants.

The Diagnosis: Lymphoepithelioma-like Carcinoma

Lymphoepithelioma-like carcinoma (LELC) is a rare, poorly differentiated, primary cutaneous neoplasm that occurs on sun-exposed skin, particularly on the head and neck of elderly individuals. It often manifests as an asymptomatic, slow-growing, flesh-colored or erythematous dermal nodule, though ulceration and tenderness have been reported.¹ Histopathologically, these neoplasms often are poorly circumscribed and can infiltrate surrounding subcutaneous and soft tissue. As a biphasic tumor, LELC is characterized by islands, nests, or trabeculae of epithelioid cells within the mid dermis surrounded by a dense lymphocytic infiltrate with plasma cells (Figure 1).¹ The epithelial component rarely communicates with the overlying epidermis and is composed of atypical polygonal cells with eosinophilic cytoplasm, vesicular nuclei, prominent nucleoli, and frequent mitosis.² These epithelial nests can be highlighted by pancytokeratin AE1/AE3 or other epithelial differentiation markers (eg, CAM 5.2, CK5/6, epithelial membrane antigen, high-molecular-weight cytokeratin), while the surrounding lymphocytic infiltrate consists of an admixture of T cells and B cells. Lymphoepithelioma-like carcinomas also can demonstrate sebaceous, eccrine, or follicular differentiations.³ The epithelial nests of LELC also are positive for p63 and epithelial membrane antigen.²

The usual treatment of LELC is wide local excision or Mohs micrographic surgery.¹ Despite the poorly differentiated morphology of the tumor, LELC has a generally good prognosis with low metastatic potential and few reports of local recurrence after incomplete excision.³ Patients who are not candidates for surgery as well as recalcitrant cases are managed with radiotherapy.¹

Cutaneous lymphadenoma (CL) is a benign adnexal neoplasm that manifests as a small, solitary, fleshcolored nodule usually in the head and neck region.⁴ Histologically, CL consists of well-circumscribed epithelial nests within the dermis that are peripherally outlined by palisading basaloid cells and filled with clear to eosinophilic epithelioid cells (Figure 2).5 The fibrotic tumor stroma often is infiltrated by numerous intralobular dendritic cells and lymphocytes that occasionally can be arranged in germinal center–like nodules.⁴ The lymphoepithelial nature of CL can be challenging to distinguish morphologically from LELC, and immunohistochemistry stains may be required. In CL, both the basaloid and epithelioid cells stain positive for pancytokeratin AE1/ AE3, but the peripheral palisaded basaloid cells also stain positive for BerEP4. Additionally, the fibrotic stroma can be highlighted by CD34 and the intralobular dendritic cells by S-100.⁴

Nasopharyngeal carcinoma (NPC), formerly known as lymphoepithelioma, refers to carcinoma arising within the epithelium of the nasopharynx.⁶ Endemic to China, NPC manifests as an enlarging nasopharyngeal mass, causing clinical symptoms such as nasal obstruction and epistaxis.⁷ Histologically, nonkeratinizing NPC exhibits a biphasic morphology consisting of epithelioid neoplastic cells and background lymphocytic infiltrates (Figure 3). The epithelial component consists of round to oval neoplastic cells with amphophilic to eosinophilic cytoplasm, vesicular nuclei, and prominent nucleoli.⁶ Nasopharyngeal carcinoma is associated strongly with the Epstein-Barr virus while LELC is not; thus, Epstein- Barr encoding region in situ hybridization can reliably distinguish these entities. Metastatic NPC is rare but has been reported; therefore, it is highly recommended to perform an otolaryngologic examination in addition to testing for Epstein-Barr virus reactivity as part of a complete evaluation.⁸

Cutaneous squamous cell carcinoma (SCC) is a common epidermal malignancy with multiple subtypes and variable morphology. The clinical presentation of SCC is similar to LELC—an enlarging hyperkeratotic papule or nodule on sun-exposed skin that often is ulcerated and tender.⁹ Histologically, poorly differentiated nonkeratinizing SCC can form nests and trabeculae of epithelioid cells that are stained by epithelial differentiation markers, resembling the epithelioid nests of LELC. Distinguishing between LELC and poorly differentiated SCC with robust inflammatory infiltrate can be challenging (Figure 4). In fact, some experts support LELC as an SCC variant rather than a separate entity.9 However, in contrast to LELC, the dermal nests of SCC usually maintain an epidermal connection and often are associated with an overlying area of SCC in situ or welldifferentiated SCC.³

Mycosis fungoides (MF) is a primary cutaneous T-cell lymphoma. It is the most common type of cutaneous lymphoma, accounting for almost 50% of all reported cases.¹⁰ Classic MF has an indolent course and progresses through several clinical stages. Patches and plaques characterize early stages; lymphadenopathy indicates progression to later stages in which erythroderma may develop with coalescence of patches, plaques, and tumors; and MF present in blood or lymph nodes characterizes the late stage. Each stage of MF is different histologically—from a superficial lichenoid infiltrate with exocytosis of malignant T cells in the patch stage, to more robust epidermotropism and dermal infiltrate in the plaque stage, and finally a dense dermal infiltrate in the late stage.¹¹ The rare syringotropic variant of MF clinically manifests as solitary or multiple erythematous lesions, often with overlying alopecia. Syringotropic MF uniquely exhibits folliculotropism and syringotropism along with syringometaplasia on histologic evaluation (Figure 5).¹² The syringometaplasia can be difficult to distinguish from the epithelial nests of LELC, particularly with the lymphocytic background. Immunohistochemical panels for T-cell markers can highlight aberrant T cells in syringotropic MF through their usual loss of CD5 and CD7, in comparison to normal T cells in LELC.¹¹ An elevated CD4:CD8 ratio of 4:1 and molecular analysis for T-cell receptor gene clonal rearrangements also can support the diagnosis of MF.¹²

The Diagnosis: Lymphoepithelioma-like Carcinoma

Lymphoepithelioma-like carcinoma (LELC) is a rare, poorly differentiated, primary cutaneous neoplasm that occurs on sun-exposed skin, particularly on the head and neck of elderly individuals. It often manifests as an asymptomatic, slow-growing, flesh-colored or erythematous dermal nodule, though ulceration and tenderness have been reported.¹ Histopathologically, these neoplasms often are poorly circumscribed and can infiltrate surrounding subcutaneous and soft tissue. As a biphasic tumor, LELC is characterized by islands, nests, or trabeculae of epithelioid cells within the mid dermis surrounded by a dense lymphocytic infiltrate with plasma cells (Figure 1).¹ The epithelial component rarely communicates with the overlying epidermis and is composed of atypical polygonal cells with eosinophilic cytoplasm, vesicular nuclei, prominent nucleoli, and frequent mitosis.² These epithelial nests can be highlighted by pancytokeratin AE1/AE3 or other epithelial differentiation markers (eg, CAM 5.2, CK5/6, epithelial membrane antigen, high-molecular-weight cytokeratin), while the surrounding lymphocytic infiltrate consists of an admixture of T cells and B cells. Lymphoepithelioma-like carcinomas also can demonstrate sebaceous, eccrine, or follicular differentiations.³ The epithelial nests of LELC also are positive for p63 and epithelial membrane antigen.²

The usual treatment of LELC is wide local excision or Mohs micrographic surgery.¹ Despite the poorly differentiated morphology of the tumor, LELC has a generally good prognosis with low metastatic potential and few reports of local recurrence after incomplete excision.³ Patients who are not candidates for surgery as well as recalcitrant cases are managed with radiotherapy.¹

Cutaneous lymphadenoma (CL) is a benign adnexal neoplasm that manifests as a small, solitary, fleshcolored nodule usually in the head and neck region.⁴ Histologically, CL consists of well-circumscribed epithelial nests within the dermis that are peripherally outlined by palisading basaloid cells and filled with clear to eosinophilic epithelioid cells (Figure 2).5 The fibrotic tumor stroma often is infiltrated by numerous intralobular dendritic cells and lymphocytes that occasionally can be arranged in germinal center–like nodules.⁴ The lymphoepithelial nature of CL can be challenging to distinguish morphologically from LELC, and immunohistochemistry stains may be required. In CL, both the basaloid and epithelioid cells stain positive for pancytokeratin AE1/ AE3, but the peripheral palisaded basaloid cells also stain positive for BerEP4. Additionally, the fibrotic stroma can be highlighted by CD34 and the intralobular dendritic cells by S-100.⁴

Nasopharyngeal carcinoma (NPC), formerly known as lymphoepithelioma, refers to carcinoma arising within the epithelium of the nasopharynx.⁶ Endemic to China, NPC manifests as an enlarging nasopharyngeal mass, causing clinical symptoms such as nasal obstruction and epistaxis.⁷ Histologically, nonkeratinizing NPC exhibits a biphasic morphology consisting of epithelioid neoplastic cells and background lymphocytic infiltrates (Figure 3). The epithelial component consists of round to oval neoplastic cells with amphophilic to eosinophilic cytoplasm, vesicular nuclei, and prominent nucleoli.⁶ Nasopharyngeal carcinoma is associated strongly with the Epstein-Barr virus while LELC is not; thus, Epstein- Barr encoding region in situ hybridization can reliably distinguish these entities. Metastatic NPC is rare but has been reported; therefore, it is highly recommended to perform an otolaryngologic examination in addition to testing for Epstein-Barr virus reactivity as part of a complete evaluation.⁸

Cutaneous squamous cell carcinoma (SCC) is a common epidermal malignancy with multiple subtypes and variable morphology. The clinical presentation of SCC is similar to LELC—an enlarging hyperkeratotic papule or nodule on sun-exposed skin that often is ulcerated and tender.⁹ Histologically, poorly differentiated nonkeratinizing SCC can form nests and trabeculae of epithelioid cells that are stained by epithelial differentiation markers, resembling the epithelioid nests of LELC. Distinguishing between LELC and poorly differentiated SCC with robust inflammatory infiltrate can be challenging (Figure 4). In fact, some experts support LELC as an SCC variant rather than a separate entity.9 However, in contrast to LELC, the dermal nests of SCC usually maintain an epidermal connection and often are associated with an overlying area of SCC in situ or welldifferentiated SCC.³

Mycosis fungoides (MF) is a primary cutaneous T-cell lymphoma. It is the most common type of cutaneous lymphoma, accounting for almost 50% of all reported cases.¹⁰ Classic MF has an indolent course and progresses through several clinical stages. Patches and plaques characterize early stages; lymphadenopathy indicates progression to later stages in which erythroderma may develop with coalescence of patches, plaques, and tumors; and MF present in blood or lymph nodes characterizes the late stage. Each stage of MF is different histologically—from a superficial lichenoid infiltrate with exocytosis of malignant T cells in the patch stage, to more robust epidermotropism and dermal infiltrate in the plaque stage, and finally a dense dermal infiltrate in the late stage.¹¹ The rare syringotropic variant of MF clinically manifests as solitary or multiple erythematous lesions, often with overlying alopecia. Syringotropic MF uniquely exhibits folliculotropism and syringotropism along with syringometaplasia on histologic evaluation (Figure 5).¹² The syringometaplasia can be difficult to distinguish from the epithelial nests of LELC, particularly with the lymphocytic background. Immunohistochemical panels for T-cell markers can highlight aberrant T cells in syringotropic MF through their usual loss of CD5 and CD7, in comparison to normal T cells in LELC.¹¹ An elevated CD4:CD8 ratio of 4:1 and molecular analysis for T-cell receptor gene clonal rearrangements also can support the diagnosis of MF.¹²

The Diagnosis: Lymphoepithelioma-like Carcinoma

Lymphoepithelioma-like carcinoma (LELC) is a rare, poorly differentiated, primary cutaneous neoplasm that occurs on sun-exposed skin, particularly on the head and neck of elderly individuals. It often manifests as an asymptomatic, slow-growing, flesh-colored or erythematous dermal nodule, though ulceration and tenderness have been reported.¹ Histopathologically, these neoplasms often are poorly circumscribed and can infiltrate surrounding subcutaneous and soft tissue. As a biphasic tumor, LELC is characterized by islands, nests, or trabeculae of epithelioid cells within the mid dermis surrounded by a dense lymphocytic infiltrate with plasma cells (Figure 1).¹ The epithelial component rarely communicates with the overlying epidermis and is composed of atypical polygonal cells with eosinophilic cytoplasm, vesicular nuclei, prominent nucleoli, and frequent mitosis.² These epithelial nests can be highlighted by pancytokeratin AE1/AE3 or other epithelial differentiation markers (eg, CAM 5.2, CK5/6, epithelial membrane antigen, high-molecular-weight cytokeratin), while the surrounding lymphocytic infiltrate consists of an admixture of T cells and B cells. Lymphoepithelioma-like carcinomas also can demonstrate sebaceous, eccrine, or follicular differentiations.³ The epithelial nests of LELC also are positive for p63 and epithelial membrane antigen.²

The usual treatment of LELC is wide local excision or Mohs micrographic surgery.¹ Despite the poorly differentiated morphology of the tumor, LELC has a generally good prognosis with low metastatic potential and few reports of local recurrence after incomplete excision.³ Patients who are not candidates for surgery as well as recalcitrant cases are managed with radiotherapy.¹

Cutaneous lymphadenoma (CL) is a benign adnexal neoplasm that manifests as a small, solitary, fleshcolored nodule usually in the head and neck region.⁴ Histologically, CL consists of well-circumscribed epithelial nests within the dermis that are peripherally outlined by palisading basaloid cells and filled with clear to eosinophilic epithelioid cells (Figure 2).5 The fibrotic tumor stroma often is infiltrated by numerous intralobular dendritic cells and lymphocytes that occasionally can be arranged in germinal center–like nodules.⁴ The lymphoepithelial nature of CL can be challenging to distinguish morphologically from LELC, and immunohistochemistry stains may be required. In CL, both the basaloid and epithelioid cells stain positive for pancytokeratin AE1/ AE3, but the peripheral palisaded basaloid cells also stain positive for BerEP4. Additionally, the fibrotic stroma can be highlighted by CD34 and the intralobular dendritic cells by S-100.⁴

Nasopharyngeal carcinoma (NPC), formerly known as lymphoepithelioma, refers to carcinoma arising within the epithelium of the nasopharynx.⁶ Endemic to China, NPC manifests as an enlarging nasopharyngeal mass, causing clinical symptoms such as nasal obstruction and epistaxis.⁷ Histologically, nonkeratinizing NPC exhibits a biphasic morphology consisting of epithelioid neoplastic cells and background lymphocytic infiltrates (Figure 3). The epithelial component consists of round to oval neoplastic cells with amphophilic to eosinophilic cytoplasm, vesicular nuclei, and prominent nucleoli.⁶ Nasopharyngeal carcinoma is associated strongly with the Epstein-Barr virus while LELC is not; thus, Epstein- Barr encoding region in situ hybridization can reliably distinguish these entities. Metastatic NPC is rare but has been reported; therefore, it is highly recommended to perform an otolaryngologic examination in addition to testing for Epstein-Barr virus reactivity as part of a complete evaluation.⁸

Cutaneous squamous cell carcinoma (SCC) is a common epidermal malignancy with multiple subtypes and variable morphology. The clinical presentation of SCC is similar to LELC—an enlarging hyperkeratotic papule or nodule on sun-exposed skin that often is ulcerated and tender.⁹ Histologically, poorly differentiated nonkeratinizing SCC can form nests and trabeculae of epithelioid cells that are stained by epithelial differentiation markers, resembling the epithelioid nests of LELC. Distinguishing between LELC and poorly differentiated SCC with robust inflammatory infiltrate can be challenging (Figure 4). In fact, some experts support LELC as an SCC variant rather than a separate entity.9 However, in contrast to LELC, the dermal nests of SCC usually maintain an epidermal connection and often are associated with an overlying area of SCC in situ or welldifferentiated SCC.³

Mycosis fungoides (MF) is a primary cutaneous T-cell lymphoma. It is the most common type of cutaneous lymphoma, accounting for almost 50% of all reported cases.¹⁰ Classic MF has an indolent course and progresses through several clinical stages. Patches and plaques characterize early stages; lymphadenopathy indicates progression to later stages in which erythroderma may develop with coalescence of patches, plaques, and tumors; and MF present in blood or lymph nodes characterizes the late stage. Each stage of MF is different histologically—from a superficial lichenoid infiltrate with exocytosis of malignant T cells in the patch stage, to more robust epidermotropism and dermal infiltrate in the plaque stage, and finally a dense dermal infiltrate in the late stage.¹¹ The rare syringotropic variant of MF clinically manifests as solitary or multiple erythematous lesions, often with overlying alopecia. Syringotropic MF uniquely exhibits folliculotropism and syringotropism along with syringometaplasia on histologic evaluation (Figure 5).¹² The syringometaplasia can be difficult to distinguish from the epithelial nests of LELC, particularly with the lymphocytic background. Immunohistochemical panels for T-cell markers can highlight aberrant T cells in syringotropic MF through their usual loss of CD5 and CD7, in comparison to normal T cells in LELC.¹¹ An elevated CD4:CD8 ratio of 4:1 and molecular analysis for T-cell receptor gene clonal rearrangements also can support the diagnosis of MF.¹²