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The Diagnosis: Pseudo-Black Hairy Tongue

Pseudo-black hairy tongue is a benign and painless disorder characterized by transient hyperpigmentation of the tongue with a substance that can be easily scraped off. In this case, the patient's lingual discoloration was secondary to the ingestion of bismuth salicylate. The phenomenon is thought to occur due to a reaction between bismuth and sulfur-containing compounds in the saliva, resulting in the characteristic black substance on the surface of the tongue that nestles between the lingual papillae.¹ An associated feature may include black stools. Other etiologic factors involved in pseudo-black hairy tongue include food coloring, tobacco, and other drugs such antibiotics and antidepressants.²  

The differential diagnosis of lingual hyperpigmentation includes lingua villosa nigra (also known as black hairy tongue), pigmented fungiform papillae of the tongue, acanthosis nigricans, and oral hairy leukoplakia. Lingua villosa nigra is a similar condition in which individuals present with a black tongue; however, the tongue also appears hairy. The tongue may appear as other colors such as brown, yellow, or green. Patients additionally may have symptoms of burning, dysgeusia, halitosis, or gagging. Poor oral hygiene, xerostomia, use of tobacco or alcohol, and different medications including antibiotics and antipsychotic medications increase the risk for developing lingua villosa nigra.^2,3 This condition is distinguished from pseudo-black hairy tongue by proliferation and elongation of the filiform papillae.³ Pigmented fungiform papillae of the tongue is a normal variant of tongue morphology, is more common in individuals with darker skin types, and primarily affects the lateral aspect and apex of the tongue.⁴ Acanthosis nigricans can appear in the oral cavity as multiple pigmented papillary lesions on the dorsal and lateral regions of the tongue and frequently involves the lips; this condition may be associated with metabolic disorders or underlying malignancy.^2,3 Oral hairy leukoplakia is caused by Epstein-Barr virus infection and typically presents as white plaques on the dorsal and ventral surfaces of the tongue; this condition largely is found in immunocompromised patients.⁵

In our patient there was an acute onset of tongue discoloration associated with ingestion of bismuth salicylate, no hypertrophy or lengthening of the lingual papillae, and no involvement of the patient's lips, which was consistent with the diagnosis of pseudo-black hairy tongue. Pseudo-black hairy tongue is transient and treated by discontinuation of offending agents and proper hygiene practices.

The Diagnosis: Pseudo-Black Hairy Tongue

Pseudo-black hairy tongue is a benign and painless disorder characterized by transient hyperpigmentation of the tongue with a substance that can be easily scraped off. In this case, the patient's lingual discoloration was secondary to the ingestion of bismuth salicylate. The phenomenon is thought to occur due to a reaction between bismuth and sulfur-containing compounds in the saliva, resulting in the characteristic black substance on the surface of the tongue that nestles between the lingual papillae.¹ An associated feature may include black stools. Other etiologic factors involved in pseudo-black hairy tongue include food coloring, tobacco, and other drugs such antibiotics and antidepressants.²  

The differential diagnosis of lingual hyperpigmentation includes lingua villosa nigra (also known as black hairy tongue), pigmented fungiform papillae of the tongue, acanthosis nigricans, and oral hairy leukoplakia. Lingua villosa nigra is a similar condition in which individuals present with a black tongue; however, the tongue also appears hairy. The tongue may appear as other colors such as brown, yellow, or green. Patients additionally may have symptoms of burning, dysgeusia, halitosis, or gagging. Poor oral hygiene, xerostomia, use of tobacco or alcohol, and different medications including antibiotics and antipsychotic medications increase the risk for developing lingua villosa nigra.^2,3 This condition is distinguished from pseudo-black hairy tongue by proliferation and elongation of the filiform papillae.³ Pigmented fungiform papillae of the tongue is a normal variant of tongue morphology, is more common in individuals with darker skin types, and primarily affects the lateral aspect and apex of the tongue.⁴ Acanthosis nigricans can appear in the oral cavity as multiple pigmented papillary lesions on the dorsal and lateral regions of the tongue and frequently involves the lips; this condition may be associated with metabolic disorders or underlying malignancy.^2,3 Oral hairy leukoplakia is caused by Epstein-Barr virus infection and typically presents as white plaques on the dorsal and ventral surfaces of the tongue; this condition largely is found in immunocompromised patients.⁵

In our patient there was an acute onset of tongue discoloration associated with ingestion of bismuth salicylate, no hypertrophy or lengthening of the lingual papillae, and no involvement of the patient's lips, which was consistent with the diagnosis of pseudo-black hairy tongue. Pseudo-black hairy tongue is transient and treated by discontinuation of offending agents and proper hygiene practices.

The Diagnosis: Pseudo-Black Hairy Tongue

Pseudo-black hairy tongue is a benign and painless disorder characterized by transient hyperpigmentation of the tongue with a substance that can be easily scraped off. In this case, the patient's lingual discoloration was secondary to the ingestion of bismuth salicylate. The phenomenon is thought to occur due to a reaction between bismuth and sulfur-containing compounds in the saliva, resulting in the characteristic black substance on the surface of the tongue that nestles between the lingual papillae.¹ An associated feature may include black stools. Other etiologic factors involved in pseudo-black hairy tongue include food coloring, tobacco, and other drugs such antibiotics and antidepressants.²  

The differential diagnosis of lingual hyperpigmentation includes lingua villosa nigra (also known as black hairy tongue), pigmented fungiform papillae of the tongue, acanthosis nigricans, and oral hairy leukoplakia. Lingua villosa nigra is a similar condition in which individuals present with a black tongue; however, the tongue also appears hairy. The tongue may appear as other colors such as brown, yellow, or green. Patients additionally may have symptoms of burning, dysgeusia, halitosis, or gagging. Poor oral hygiene, xerostomia, use of tobacco or alcohol, and different medications including antibiotics and antipsychotic medications increase the risk for developing lingua villosa nigra.^2,3 This condition is distinguished from pseudo-black hairy tongue by proliferation and elongation of the filiform papillae.³ Pigmented fungiform papillae of the tongue is a normal variant of tongue morphology, is more common in individuals with darker skin types, and primarily affects the lateral aspect and apex of the tongue.⁴ Acanthosis nigricans can appear in the oral cavity as multiple pigmented papillary lesions on the dorsal and lateral regions of the tongue and frequently involves the lips; this condition may be associated with metabolic disorders or underlying malignancy.^2,3 Oral hairy leukoplakia is caused by Epstein-Barr virus infection and typically presents as white plaques on the dorsal and ventral surfaces of the tongue; this condition largely is found in immunocompromised patients.⁵

In our patient there was an acute onset of tongue discoloration associated with ingestion of bismuth salicylate, no hypertrophy or lengthening of the lingual papillae, and no involvement of the patient's lips, which was consistent with the diagnosis of pseudo-black hairy tongue. Pseudo-black hairy tongue is transient and treated by discontinuation of offending agents and proper hygiene practices.

The Diagnosis: Cutaneous Metastasis 

Histopathology demonstrated ulceration of the epidermis with necrosis of the papillary dermis. There was a diffuse infiltration of pleomorphic and atypical epithelioid cells in the reticular dermis (Figure). Focally there was ductal and glandular differentiation. The stroma was sclerotic. At the deep aspect of the biopsy specimen, tumor cells intercalated between collagen bundles in linear strands. Atypical mitoses were common, and necrosis en masse was seen. An immunohistochemical panel also was performed. Tissue from the biopsy was strongly positive for CDX-2 and cytokeratin 20 and diffusely negative for cytokeratin 7, gross cystic disease fluid protein 15, and prostate-specific antigen. The other biopsy was sent for cultures and grew no organisms, which confirmed the diagnosis of cutaneous metastasis from the patient's primary colonic adenocarcinoma. Due to the poor prognosis and his overall poor health, our patient opted for palliative care. 

Based on large retrospective studies, the frequency of cutaneous metastasis for patients diagnosed with any malignancy is 0.7% to 9.0%.^1-4 The third most common malignancy in both sexes is colorectal cancer, affecting approximately 5% of the US population.³ The frequency of cutaneous metastases from colorectal cancer is 0.81% to 3.9%.^1,2,4,5 Generally, cutaneous metastases present within 2 to 3 years from diagnosis of primary malignancy.^6,7 The most common sites for cutaneous metastases in a patient with colorectal cancer are the abdomen and pelvic region, often at surgical sites.^1-4,6-9  

The clinical presentation of cutaneous metastases varies greatly, and as a result, they commonly are misdiagnosed.^6,7 Although treatment with many antibiotics and antifungals had failed in our patient, the examination still was concerning for a possible granulomatous infection vs malignancy. With the history of colon cancer, radiation treatment, and chemotherapy, the possible malignancy diagnoses included primary skin cancers, viral tumors, and cutaneous metastasis. The initial evaluations had focused on infectious causes and resulted in 6 weeks of misdiagnosis and inappropriate therapy. Despite cutaneous metastases being uncommon, there should be a high index of suspicion for lesions in patients who have a history of cancer, especially if the lesion does not respond to treatment.^2,6,7  

Physical examination in our patient showed a high tumor burden as well as evidence of carcinoma erysipeloides on the lower abdomen and thighs, in addition to carcinoma en cuirasse throughout the pubic region. Carcinoma erysipeloides was first described in 1893 in a patient with breast cancer: "The erythematous infiltration of the skin was very superficial, and was attended simply by redness with a slight degree of induration. Until touched by the finger the condition might easily have been taken for a slightly-marked form of erysipelas."¹⁰ The clinical findings are a result of lymphatic and vascular obstruction.^3,9 The breast is the most common location to find carcinoma erysipeloides.³ It is an unusual occurrence to find it on the abdomen from colonic adenocarcinoma. The term cancer en cuirasse was coined in 1838 to describe the cutaneous manifestation of breast cancer that caused the skin to resemble the metal breastplate of a cuirasser.⁴ Similar to carcinoma erysipeloides, carcinoma en cuirasse most commonly is found as cutaneous metastasis from breast cancer, not from colonic adenocarcinoma.³  

The histologic characteristics of cutaneous metastases in general are similar to the primary malignancy but can be more poorly differentiated.⁷ Generally, neoplastic cells are seen in the lymphatic and blood vessels, and a large portion of the tumor is confined to the deep dermis and in the subcutaneous fat.^3,6 Histologic features of colonic adenocarcinoma metastases can demonstrate a well-differentiated, glandular architecture with mucin-secreting cells.^3,8,9 There also is a histologic pattern of neoplastic cells arranging themselves between collagen bundles in linear strands; this finding more commonly is seen in adenocarcinoma of the breast but also was seen in our patient.^3,9 With immunohistochemical staining, a truncated panel of cytokeratin 7, cytokeratin 20, and S-100 had a diagnostic accuracy of 100% for cutaneous metastases from colonic adenocarcinoma in one study. The pattern of all colonic adenocarcinomas was cytokeratin 20 positive and cytokeratin 7 and S-100 negative.⁶ 

Cutaneous metastases typically demonstrate widespread and rapidly progressive disease.^3,9 Survival studies of cutaneous metastases showed that 48% to 66% of patients died within the first 6 months.^3,6 Specifically, cutaneous metastases from colorectal cancers showed a median survival of 3 to 5 months.^6,7 Currently there are no treatment guidelines for cutaneous metastases.   

The Diagnosis: Cutaneous Metastasis 

Histopathology demonstrated ulceration of the epidermis with necrosis of the papillary dermis. There was a diffuse infiltration of pleomorphic and atypical epithelioid cells in the reticular dermis (Figure). Focally there was ductal and glandular differentiation. The stroma was sclerotic. At the deep aspect of the biopsy specimen, tumor cells intercalated between collagen bundles in linear strands. Atypical mitoses were common, and necrosis en masse was seen. An immunohistochemical panel also was performed. Tissue from the biopsy was strongly positive for CDX-2 and cytokeratin 20 and diffusely negative for cytokeratin 7, gross cystic disease fluid protein 15, and prostate-specific antigen. The other biopsy was sent for cultures and grew no organisms, which confirmed the diagnosis of cutaneous metastasis from the patient's primary colonic adenocarcinoma. Due to the poor prognosis and his overall poor health, our patient opted for palliative care. 

Based on large retrospective studies, the frequency of cutaneous metastasis for patients diagnosed with any malignancy is 0.7% to 9.0%.^1-4 The third most common malignancy in both sexes is colorectal cancer, affecting approximately 5% of the US population.³ The frequency of cutaneous metastases from colorectal cancer is 0.81% to 3.9%.^1,2,4,5 Generally, cutaneous metastases present within 2 to 3 years from diagnosis of primary malignancy.^6,7 The most common sites for cutaneous metastases in a patient with colorectal cancer are the abdomen and pelvic region, often at surgical sites.^1-4,6-9  

The clinical presentation of cutaneous metastases varies greatly, and as a result, they commonly are misdiagnosed.^6,7 Although treatment with many antibiotics and antifungals had failed in our patient, the examination still was concerning for a possible granulomatous infection vs malignancy. With the history of colon cancer, radiation treatment, and chemotherapy, the possible malignancy diagnoses included primary skin cancers, viral tumors, and cutaneous metastasis. The initial evaluations had focused on infectious causes and resulted in 6 weeks of misdiagnosis and inappropriate therapy. Despite cutaneous metastases being uncommon, there should be a high index of suspicion for lesions in patients who have a history of cancer, especially if the lesion does not respond to treatment.^2,6,7  

Physical examination in our patient showed a high tumor burden as well as evidence of carcinoma erysipeloides on the lower abdomen and thighs, in addition to carcinoma en cuirasse throughout the pubic region. Carcinoma erysipeloides was first described in 1893 in a patient with breast cancer: "The erythematous infiltration of the skin was very superficial, and was attended simply by redness with a slight degree of induration. Until touched by the finger the condition might easily have been taken for a slightly-marked form of erysipelas."¹⁰ The clinical findings are a result of lymphatic and vascular obstruction.^3,9 The breast is the most common location to find carcinoma erysipeloides.³ It is an unusual occurrence to find it on the abdomen from colonic adenocarcinoma. The term cancer en cuirasse was coined in 1838 to describe the cutaneous manifestation of breast cancer that caused the skin to resemble the metal breastplate of a cuirasser.⁴ Similar to carcinoma erysipeloides, carcinoma en cuirasse most commonly is found as cutaneous metastasis from breast cancer, not from colonic adenocarcinoma.³  

The histologic characteristics of cutaneous metastases in general are similar to the primary malignancy but can be more poorly differentiated.⁷ Generally, neoplastic cells are seen in the lymphatic and blood vessels, and a large portion of the tumor is confined to the deep dermis and in the subcutaneous fat.^3,6 Histologic features of colonic adenocarcinoma metastases can demonstrate a well-differentiated, glandular architecture with mucin-secreting cells.^3,8,9 There also is a histologic pattern of neoplastic cells arranging themselves between collagen bundles in linear strands; this finding more commonly is seen in adenocarcinoma of the breast but also was seen in our patient.^3,9 With immunohistochemical staining, a truncated panel of cytokeratin 7, cytokeratin 20, and S-100 had a diagnostic accuracy of 100% for cutaneous metastases from colonic adenocarcinoma in one study. The pattern of all colonic adenocarcinomas was cytokeratin 20 positive and cytokeratin 7 and S-100 negative.⁶ 

Cutaneous metastases typically demonstrate widespread and rapidly progressive disease.^3,9 Survival studies of cutaneous metastases showed that 48% to 66% of patients died within the first 6 months.^3,6 Specifically, cutaneous metastases from colorectal cancers showed a median survival of 3 to 5 months.^6,7 Currently there are no treatment guidelines for cutaneous metastases.   

The Diagnosis: Cutaneous Metastasis 

Histopathology demonstrated ulceration of the epidermis with necrosis of the papillary dermis. There was a diffuse infiltration of pleomorphic and atypical epithelioid cells in the reticular dermis (Figure). Focally there was ductal and glandular differentiation. The stroma was sclerotic. At the deep aspect of the biopsy specimen, tumor cells intercalated between collagen bundles in linear strands. Atypical mitoses were common, and necrosis en masse was seen. An immunohistochemical panel also was performed. Tissue from the biopsy was strongly positive for CDX-2 and cytokeratin 20 and diffusely negative for cytokeratin 7, gross cystic disease fluid protein 15, and prostate-specific antigen. The other biopsy was sent for cultures and grew no organisms, which confirmed the diagnosis of cutaneous metastasis from the patient's primary colonic adenocarcinoma. Due to the poor prognosis and his overall poor health, our patient opted for palliative care. 

Based on large retrospective studies, the frequency of cutaneous metastasis for patients diagnosed with any malignancy is 0.7% to 9.0%.^1-4 The third most common malignancy in both sexes is colorectal cancer, affecting approximately 5% of the US population.³ The frequency of cutaneous metastases from colorectal cancer is 0.81% to 3.9%.^1,2,4,5 Generally, cutaneous metastases present within 2 to 3 years from diagnosis of primary malignancy.^6,7 The most common sites for cutaneous metastases in a patient with colorectal cancer are the abdomen and pelvic region, often at surgical sites.^1-4,6-9  

The clinical presentation of cutaneous metastases varies greatly, and as a result, they commonly are misdiagnosed.^6,7 Although treatment with many antibiotics and antifungals had failed in our patient, the examination still was concerning for a possible granulomatous infection vs malignancy. With the history of colon cancer, radiation treatment, and chemotherapy, the possible malignancy diagnoses included primary skin cancers, viral tumors, and cutaneous metastasis. The initial evaluations had focused on infectious causes and resulted in 6 weeks of misdiagnosis and inappropriate therapy. Despite cutaneous metastases being uncommon, there should be a high index of suspicion for lesions in patients who have a history of cancer, especially if the lesion does not respond to treatment.^2,6,7  

Physical examination in our patient showed a high tumor burden as well as evidence of carcinoma erysipeloides on the lower abdomen and thighs, in addition to carcinoma en cuirasse throughout the pubic region. Carcinoma erysipeloides was first described in 1893 in a patient with breast cancer: "The erythematous infiltration of the skin was very superficial, and was attended simply by redness with a slight degree of induration. Until touched by the finger the condition might easily have been taken for a slightly-marked form of erysipelas."¹⁰ The clinical findings are a result of lymphatic and vascular obstruction.^3,9 The breast is the most common location to find carcinoma erysipeloides.³ It is an unusual occurrence to find it on the abdomen from colonic adenocarcinoma. The term cancer en cuirasse was coined in 1838 to describe the cutaneous manifestation of breast cancer that caused the skin to resemble the metal breastplate of a cuirasser.⁴ Similar to carcinoma erysipeloides, carcinoma en cuirasse most commonly is found as cutaneous metastasis from breast cancer, not from colonic adenocarcinoma.³  

The histologic characteristics of cutaneous metastases in general are similar to the primary malignancy but can be more poorly differentiated.⁷ Generally, neoplastic cells are seen in the lymphatic and blood vessels, and a large portion of the tumor is confined to the deep dermis and in the subcutaneous fat.^3,6 Histologic features of colonic adenocarcinoma metastases can demonstrate a well-differentiated, glandular architecture with mucin-secreting cells.^3,8,9 There also is a histologic pattern of neoplastic cells arranging themselves between collagen bundles in linear strands; this finding more commonly is seen in adenocarcinoma of the breast but also was seen in our patient.^3,9 With immunohistochemical staining, a truncated panel of cytokeratin 7, cytokeratin 20, and S-100 had a diagnostic accuracy of 100% for cutaneous metastases from colonic adenocarcinoma in one study. The pattern of all colonic adenocarcinomas was cytokeratin 20 positive and cytokeratin 7 and S-100 negative.⁶ 

Cutaneous metastases typically demonstrate widespread and rapidly progressive disease.^3,9 Survival studies of cutaneous metastases showed that 48% to 66% of patients died within the first 6 months.^3,6 Specifically, cutaneous metastases from colorectal cancers showed a median survival of 3 to 5 months.^6,7 Currently there are no treatment guidelines for cutaneous metastases.   

The Diagnosis: Dermatofibroma With Sebaceous Induction 

The biopsy of the lesion revealed a fibrohistiocytic dermal pattern with overlying benign epidermal and sebaceous hyperplasia with a proliferation of fibroblasts in the dermis. Other sections revealed hyperplastic sebaceous glands of the superficial and mid dermis. These findings were suggestive of a dermatofibroma (DF) that had induced epidermal and sebaceous hyperplasia.  

Dermatofibromas are common benign fibrous soft tissue growths that account for approximately 3% of dermatopathology specimens.¹ The etiology of DFs is unknown; however, they are thought to arise from sites of prior trauma or arthropod bites. Multiple or eruptive DFs have been reported in patients with lupus and atopic dermatitis.² They commonly appear as round firm nodules measuring less than 1 cm in diameter on the extremities of young adults. Eruptive dermatofibromas also have been reported in human immunodeficiency virus-positive and immunosuppressed patients.^3,4 On physical examination, gently pinching the lesion causes a downward movement known as the "dimple sign." If left undisturbed, DFs persist but may undergo partial regression, especially in the center; they also may be excised if symptomatic.  

The clinical differential for this papule included a scar and sebaceous hyperplasia. The lack of history of skin cancer or prior procedure made a scar less likely. Sebaceous glands are less prominent on the shoulders, making sebaceous hyperplasia less likely, though dermoscopy showed pale yellow lobules. Sebaceous adenomas most commonly are seen on the head or neck and present as a flesh-colored papule. Sebaceous induction by DFs is rare but has been reported in the literature.^5,6 

The histology of DFs is described as a nodular proliferation of spindle-shaped fibroblasts and myofibroblasts with short intersecting fascicles. A predilection for sebaceous induction from an underlying DF on the shoulder has been reported.⁵ Sebaceous differentiation has been reported in 16% to 31.6% of DFs.^5,6 Seborrheic keratosis-like epidermal hyperplasia frequently has been seen in DFs with sebaceous induction in comparison to DFs without sebaceous induction.⁵ Immunohistochemical stains are important to help differentiate DF from dermatofibrosarcoma protuberans, especially when approaching the subcutis. Dermatofibromas stain positive for factor XIIIa and negative for CD34, whereas dermatofibrosarcoma protuberans stain negative for factor XIIIa and positive for CD34.⁷ Dermatofibromas also demonstrate positive immunostaining for vimentin, stromelysin 3,⁸ muscle-specific actin, and CD68.  

The Diagnosis: Dermatofibroma With Sebaceous Induction 

The biopsy of the lesion revealed a fibrohistiocytic dermal pattern with overlying benign epidermal and sebaceous hyperplasia with a proliferation of fibroblasts in the dermis. Other sections revealed hyperplastic sebaceous glands of the superficial and mid dermis. These findings were suggestive of a dermatofibroma (DF) that had induced epidermal and sebaceous hyperplasia.  

Dermatofibromas are common benign fibrous soft tissue growths that account for approximately 3% of dermatopathology specimens.¹ The etiology of DFs is unknown; however, they are thought to arise from sites of prior trauma or arthropod bites. Multiple or eruptive DFs have been reported in patients with lupus and atopic dermatitis.² They commonly appear as round firm nodules measuring less than 1 cm in diameter on the extremities of young adults. Eruptive dermatofibromas also have been reported in human immunodeficiency virus-positive and immunosuppressed patients.^3,4 On physical examination, gently pinching the lesion causes a downward movement known as the "dimple sign." If left undisturbed, DFs persist but may undergo partial regression, especially in the center; they also may be excised if symptomatic.  

The clinical differential for this papule included a scar and sebaceous hyperplasia. The lack of history of skin cancer or prior procedure made a scar less likely. Sebaceous glands are less prominent on the shoulders, making sebaceous hyperplasia less likely, though dermoscopy showed pale yellow lobules. Sebaceous adenomas most commonly are seen on the head or neck and present as a flesh-colored papule. Sebaceous induction by DFs is rare but has been reported in the literature.^5,6 

The histology of DFs is described as a nodular proliferation of spindle-shaped fibroblasts and myofibroblasts with short intersecting fascicles. A predilection for sebaceous induction from an underlying DF on the shoulder has been reported.⁵ Sebaceous differentiation has been reported in 16% to 31.6% of DFs.^5,6 Seborrheic keratosis-like epidermal hyperplasia frequently has been seen in DFs with sebaceous induction in comparison to DFs without sebaceous induction.⁵ Immunohistochemical stains are important to help differentiate DF from dermatofibrosarcoma protuberans, especially when approaching the subcutis. Dermatofibromas stain positive for factor XIIIa and negative for CD34, whereas dermatofibrosarcoma protuberans stain negative for factor XIIIa and positive for CD34.⁷ Dermatofibromas also demonstrate positive immunostaining for vimentin, stromelysin 3,⁸ muscle-specific actin, and CD68.  

The Diagnosis: Dermatofibroma With Sebaceous Induction 

The biopsy of the lesion revealed a fibrohistiocytic dermal pattern with overlying benign epidermal and sebaceous hyperplasia with a proliferation of fibroblasts in the dermis. Other sections revealed hyperplastic sebaceous glands of the superficial and mid dermis. These findings were suggestive of a dermatofibroma (DF) that had induced epidermal and sebaceous hyperplasia.  

Dermatofibromas are common benign fibrous soft tissue growths that account for approximately 3% of dermatopathology specimens.¹ The etiology of DFs is unknown; however, they are thought to arise from sites of prior trauma or arthropod bites. Multiple or eruptive DFs have been reported in patients with lupus and atopic dermatitis.² They commonly appear as round firm nodules measuring less than 1 cm in diameter on the extremities of young adults. Eruptive dermatofibromas also have been reported in human immunodeficiency virus-positive and immunosuppressed patients.^3,4 On physical examination, gently pinching the lesion causes a downward movement known as the "dimple sign." If left undisturbed, DFs persist but may undergo partial regression, especially in the center; they also may be excised if symptomatic.  

The clinical differential for this papule included a scar and sebaceous hyperplasia. The lack of history of skin cancer or prior procedure made a scar less likely. Sebaceous glands are less prominent on the shoulders, making sebaceous hyperplasia less likely, though dermoscopy showed pale yellow lobules. Sebaceous adenomas most commonly are seen on the head or neck and present as a flesh-colored papule. Sebaceous induction by DFs is rare but has been reported in the literature.^5,6 

The histology of DFs is described as a nodular proliferation of spindle-shaped fibroblasts and myofibroblasts with short intersecting fascicles. A predilection for sebaceous induction from an underlying DF on the shoulder has been reported.⁵ Sebaceous differentiation has been reported in 16% to 31.6% of DFs.^5,6 Seborrheic keratosis-like epidermal hyperplasia frequently has been seen in DFs with sebaceous induction in comparison to DFs without sebaceous induction.⁵ Immunohistochemical stains are important to help differentiate DF from dermatofibrosarcoma protuberans, especially when approaching the subcutis. Dermatofibromas stain positive for factor XIIIa and negative for CD34, whereas dermatofibrosarcoma protuberans stain negative for factor XIIIa and positive for CD34.⁷ Dermatofibromas also demonstrate positive immunostaining for vimentin, stromelysin 3,⁸ muscle-specific actin, and CD68.  

The Diagnosis: Rumpel-Leede Phenomenon 

Rumpel-Leede (R-L) phenomenon describes the rare benign occurrence of dermal capillaries acutely rupturing following the administration of a tourniquetlike force on an extremity,¹ which manifests as asymptomatic petechiae and ecchymoses on a distal extremity, usually following noninvasive measurement of blood pressure.² Rumpel-Leede phenomenon represents an underrecognized entity that either is excluded or minimally referenced in most dermatology textbooks. The R-L sign initially was described in the early 1900s after it was observed that tourniquets applied to the arms of patients with scarlet fever would lead to the development of petechiae in that extremity.³ It later was elucidated that underlying vascular disease predisposes to dermal capillary fragility, a risk factor for R-L phenomenon to occur upon application of a tourniquet. Rumpel-Leede phenomenon has been noted in patients with diabetes mellitus, acute or chronic hypertension, and thrombocytopenia.⁴ In addition to being hypertensive and diabetic, our patient had been taking amlodipine and diltiazem. Calcium channel blockers have been linked to R-L phenomenon in case reports as well as in a study of calcium channel blockers inducing capillary fragility in vivo.⁵ Rumpel-Leede phenomenon also has been noted in patients with tightly fitting garments and infants carried in baby carriers.¹ 

The differential diagnosis for R-L phenomenon includes actinic purpura, small vessel vasculitis, disseminated intravascular coagulation (DIC), and deep vein thrombosis (DVT). Actinic purpura, also called solar purpura or senile purpura, represents the petechiae and ecchymoses that are associated with aging skin. It is thought to occur when DNA damage, UV-induced solar elastosis, and decreased lipids in the stratum corneum cause a weakened ability to contain red blood cell extravasation from capillaries.⁶ Due to the lack of history of trauma and clear association with the blood pressure cuff placement in our patient, a diagnosis of actinic purpura was unlikely. In small vessel vasculitis, patients classically present with nonblanching palpable purpura frequently distributed over the lower extremities. The isolation of the lesions to only the left arm lowered the suspicion for vasculitis. Cutaneous manifestations of DIC and other hypercoagulable states may include purpura, livedo reticularis, atrophie blanche, and in extreme cases purpura fulminans. Routine laboratory examination reveals thrombocytopenia, prolonged prothrombin time/partial thromboplastin time, and hemolytic anemia.⁷ Although our patient had the risk factors of recent infection and surgery, a hemoglobin level of 10.9 g/dL (reference range, 14.0-17.5 g/dL) and platelet count of 279,000/µL (reference range, 150,000-350,000/µL) excluded DIC as the probable diagnosis. Our patient was at an overall increased risk for DVT due to his prolonged hospital stay, increased age, and other factors. Despite these risk factors, the lack of pain or swelling made this diagnosis unlikely. Furthermore, our patient was heparinized throughout his hospital stay, and upper extremity DVT accounts for only 4% to 10% of the total DVT incidence.⁵ 

Although R-L phenomenon is a benign, self-limited condition, it may be necessary in some cases to rule out more serious underlying etiologies with investigative workup comprised of a complete blood cell count, coagulation profile, and basic metabolic panel. However, recognition of the R-L phenomenon in the right clinical context of localized petechiae or ecchymoses with a history of a tourniquetlike force may prevent an unnecessary and costly workup. Patients should be encouraged that R-L phenomenon will resolve over time with identification and correction of the tourniquetlike force. In this case, we recommended loosening of the sphygmomanometer cuff and alternating extremities to which the cuff was to be placed, which resulted in complete clearance of the petechiae and ecchymoses within 5 days.  

The Diagnosis: Rumpel-Leede Phenomenon 

Rumpel-Leede (R-L) phenomenon describes the rare benign occurrence of dermal capillaries acutely rupturing following the administration of a tourniquetlike force on an extremity,¹ which manifests as asymptomatic petechiae and ecchymoses on a distal extremity, usually following noninvasive measurement of blood pressure.² Rumpel-Leede phenomenon represents an underrecognized entity that either is excluded or minimally referenced in most dermatology textbooks. The R-L sign initially was described in the early 1900s after it was observed that tourniquets applied to the arms of patients with scarlet fever would lead to the development of petechiae in that extremity.³ It later was elucidated that underlying vascular disease predisposes to dermal capillary fragility, a risk factor for R-L phenomenon to occur upon application of a tourniquet. Rumpel-Leede phenomenon has been noted in patients with diabetes mellitus, acute or chronic hypertension, and thrombocytopenia.⁴ In addition to being hypertensive and diabetic, our patient had been taking amlodipine and diltiazem. Calcium channel blockers have been linked to R-L phenomenon in case reports as well as in a study of calcium channel blockers inducing capillary fragility in vivo.⁵ Rumpel-Leede phenomenon also has been noted in patients with tightly fitting garments and infants carried in baby carriers.¹ 

The differential diagnosis for R-L phenomenon includes actinic purpura, small vessel vasculitis, disseminated intravascular coagulation (DIC), and deep vein thrombosis (DVT). Actinic purpura, also called solar purpura or senile purpura, represents the petechiae and ecchymoses that are associated with aging skin. It is thought to occur when DNA damage, UV-induced solar elastosis, and decreased lipids in the stratum corneum cause a weakened ability to contain red blood cell extravasation from capillaries.⁶ Due to the lack of history of trauma and clear association with the blood pressure cuff placement in our patient, a diagnosis of actinic purpura was unlikely. In small vessel vasculitis, patients classically present with nonblanching palpable purpura frequently distributed over the lower extremities. The isolation of the lesions to only the left arm lowered the suspicion for vasculitis. Cutaneous manifestations of DIC and other hypercoagulable states may include purpura, livedo reticularis, atrophie blanche, and in extreme cases purpura fulminans. Routine laboratory examination reveals thrombocytopenia, prolonged prothrombin time/partial thromboplastin time, and hemolytic anemia.⁷ Although our patient had the risk factors of recent infection and surgery, a hemoglobin level of 10.9 g/dL (reference range, 14.0-17.5 g/dL) and platelet count of 279,000/µL (reference range, 150,000-350,000/µL) excluded DIC as the probable diagnosis. Our patient was at an overall increased risk for DVT due to his prolonged hospital stay, increased age, and other factors. Despite these risk factors, the lack of pain or swelling made this diagnosis unlikely. Furthermore, our patient was heparinized throughout his hospital stay, and upper extremity DVT accounts for only 4% to 10% of the total DVT incidence.⁵ 

Although R-L phenomenon is a benign, self-limited condition, it may be necessary in some cases to rule out more serious underlying etiologies with investigative workup comprised of a complete blood cell count, coagulation profile, and basic metabolic panel. However, recognition of the R-L phenomenon in the right clinical context of localized petechiae or ecchymoses with a history of a tourniquetlike force may prevent an unnecessary and costly workup. Patients should be encouraged that R-L phenomenon will resolve over time with identification and correction of the tourniquetlike force. In this case, we recommended loosening of the sphygmomanometer cuff and alternating extremities to which the cuff was to be placed, which resulted in complete clearance of the petechiae and ecchymoses within 5 days.  

The Diagnosis: Rumpel-Leede Phenomenon 

Rumpel-Leede (R-L) phenomenon describes the rare benign occurrence of dermal capillaries acutely rupturing following the administration of a tourniquetlike force on an extremity,¹ which manifests as asymptomatic petechiae and ecchymoses on a distal extremity, usually following noninvasive measurement of blood pressure.² Rumpel-Leede phenomenon represents an underrecognized entity that either is excluded or minimally referenced in most dermatology textbooks. The R-L sign initially was described in the early 1900s after it was observed that tourniquets applied to the arms of patients with scarlet fever would lead to the development of petechiae in that extremity.³ It later was elucidated that underlying vascular disease predisposes to dermal capillary fragility, a risk factor for R-L phenomenon to occur upon application of a tourniquet. Rumpel-Leede phenomenon has been noted in patients with diabetes mellitus, acute or chronic hypertension, and thrombocytopenia.⁴ In addition to being hypertensive and diabetic, our patient had been taking amlodipine and diltiazem. Calcium channel blockers have been linked to R-L phenomenon in case reports as well as in a study of calcium channel blockers inducing capillary fragility in vivo.⁵ Rumpel-Leede phenomenon also has been noted in patients with tightly fitting garments and infants carried in baby carriers.¹ 

The differential diagnosis for R-L phenomenon includes actinic purpura, small vessel vasculitis, disseminated intravascular coagulation (DIC), and deep vein thrombosis (DVT). Actinic purpura, also called solar purpura or senile purpura, represents the petechiae and ecchymoses that are associated with aging skin. It is thought to occur when DNA damage, UV-induced solar elastosis, and decreased lipids in the stratum corneum cause a weakened ability to contain red blood cell extravasation from capillaries.⁶ Due to the lack of history of trauma and clear association with the blood pressure cuff placement in our patient, a diagnosis of actinic purpura was unlikely. In small vessel vasculitis, patients classically present with nonblanching palpable purpura frequently distributed over the lower extremities. The isolation of the lesions to only the left arm lowered the suspicion for vasculitis. Cutaneous manifestations of DIC and other hypercoagulable states may include purpura, livedo reticularis, atrophie blanche, and in extreme cases purpura fulminans. Routine laboratory examination reveals thrombocytopenia, prolonged prothrombin time/partial thromboplastin time, and hemolytic anemia.⁷ Although our patient had the risk factors of recent infection and surgery, a hemoglobin level of 10.9 g/dL (reference range, 14.0-17.5 g/dL) and platelet count of 279,000/µL (reference range, 150,000-350,000/µL) excluded DIC as the probable diagnosis. Our patient was at an overall increased risk for DVT due to his prolonged hospital stay, increased age, and other factors. Despite these risk factors, the lack of pain or swelling made this diagnosis unlikely. Furthermore, our patient was heparinized throughout his hospital stay, and upper extremity DVT accounts for only 4% to 10% of the total DVT incidence.⁵ 

Although R-L phenomenon is a benign, self-limited condition, it may be necessary in some cases to rule out more serious underlying etiologies with investigative workup comprised of a complete blood cell count, coagulation profile, and basic metabolic panel. However, recognition of the R-L phenomenon in the right clinical context of localized petechiae or ecchymoses with a history of a tourniquetlike force may prevent an unnecessary and costly workup. Patients should be encouraged that R-L phenomenon will resolve over time with identification and correction of the tourniquetlike force. In this case, we recommended loosening of the sphygmomanometer cuff and alternating extremities to which the cuff was to be placed, which resulted in complete clearance of the petechiae and ecchymoses within 5 days.  

The Diagnosis: Fiddler's Neck 

A thorough patient history revealed that the patient was retired and played violin regularly in the local orchestra. Fiddler's neck, or violin hickey, is an uncommon physical examination finding and often is considered a badge of honor by musicians who develop it. Fiddler's neck is a hobby-related callus seen in highly dedicated violin and viola players, and in some circles, it is known as a mark of greatness. In one instance, members of the public were asked to display a violin hickey before they were allowed to play a $3.5 million violin on public display in London, England.¹ Fiddler's neck is a benign submandibular lesion caused by pressure and friction on the skin from extensive time spent playing the instrument. The primary cause is thought to be mechanical, but it is not fully understood why the lesion occurs in some musicians and not others, regardless of playing time.¹ This submandibular fiddler's neck is distinct from a similarly named supraclavicular lesion, which represents an allergic contact dermatitis to the nickel bracket of the instrument's chin rest and presents with eczematous scale and/or vesicles.^2,3 Submandibular fiddler's neck presents with some combination of erythema, edema, lichenification, and scarring just below the angle of the jaw. Occasionally, papules, pustules, and even cyst formation may be noted. Lesions are sometimes mistaken for malignancy or lymphedema. Therefore, a thorough history and clinical expertise are important, as surgical excision should be avoided.²  

Depending on presentation, the differential diagnosis also may include malignant melanoma due to irregular pigmentation, branchial cleft cyst or sialolithiasis due to location and texture, or a tumor of the salivary gland. 

Management of fiddler's neck may include topical steroids, neck or instrument padding, or decreased playing time. However, the lesion often is worn with pride, seen as a testament to the musician's dedication, and reassurance generally is most appropriate.¹  

The Diagnosis: Fiddler's Neck 

A thorough patient history revealed that the patient was retired and played violin regularly in the local orchestra. Fiddler's neck, or violin hickey, is an uncommon physical examination finding and often is considered a badge of honor by musicians who develop it. Fiddler's neck is a hobby-related callus seen in highly dedicated violin and viola players, and in some circles, it is known as a mark of greatness. In one instance, members of the public were asked to display a violin hickey before they were allowed to play a $3.5 million violin on public display in London, England.¹ Fiddler's neck is a benign submandibular lesion caused by pressure and friction on the skin from extensive time spent playing the instrument. The primary cause is thought to be mechanical, but it is not fully understood why the lesion occurs in some musicians and not others, regardless of playing time.¹ This submandibular fiddler's neck is distinct from a similarly named supraclavicular lesion, which represents an allergic contact dermatitis to the nickel bracket of the instrument's chin rest and presents with eczematous scale and/or vesicles.^2,3 Submandibular fiddler's neck presents with some combination of erythema, edema, lichenification, and scarring just below the angle of the jaw. Occasionally, papules, pustules, and even cyst formation may be noted. Lesions are sometimes mistaken for malignancy or lymphedema. Therefore, a thorough history and clinical expertise are important, as surgical excision should be avoided.²  

Depending on presentation, the differential diagnosis also may include malignant melanoma due to irregular pigmentation, branchial cleft cyst or sialolithiasis due to location and texture, or a tumor of the salivary gland. 

Management of fiddler's neck may include topical steroids, neck or instrument padding, or decreased playing time. However, the lesion often is worn with pride, seen as a testament to the musician's dedication, and reassurance generally is most appropriate.¹  

The Diagnosis: Fiddler's Neck 

A thorough patient history revealed that the patient was retired and played violin regularly in the local orchestra. Fiddler's neck, or violin hickey, is an uncommon physical examination finding and often is considered a badge of honor by musicians who develop it. Fiddler's neck is a hobby-related callus seen in highly dedicated violin and viola players, and in some circles, it is known as a mark of greatness. In one instance, members of the public were asked to display a violin hickey before they were allowed to play a $3.5 million violin on public display in London, England.¹ Fiddler's neck is a benign submandibular lesion caused by pressure and friction on the skin from extensive time spent playing the instrument. The primary cause is thought to be mechanical, but it is not fully understood why the lesion occurs in some musicians and not others, regardless of playing time.¹ This submandibular fiddler's neck is distinct from a similarly named supraclavicular lesion, which represents an allergic contact dermatitis to the nickel bracket of the instrument's chin rest and presents with eczematous scale and/or vesicles.^2,3 Submandibular fiddler's neck presents with some combination of erythema, edema, lichenification, and scarring just below the angle of the jaw. Occasionally, papules, pustules, and even cyst formation may be noted. Lesions are sometimes mistaken for malignancy or lymphedema. Therefore, a thorough history and clinical expertise are important, as surgical excision should be avoided.²  

Depending on presentation, the differential diagnosis also may include malignant melanoma due to irregular pigmentation, branchial cleft cyst or sialolithiasis due to location and texture, or a tumor of the salivary gland. 

Management of fiddler's neck may include topical steroids, neck or instrument padding, or decreased playing time. However, the lesion often is worn with pride, seen as a testament to the musician's dedication, and reassurance generally is most appropriate.¹  

The Diagnosis: Candidal Intertrigo  

The biopsy confirmed a diagnosis of severe hyperkeratotic candidal intertrigo with no evidence of Hailey-Hailey disease. Hematoxylin and eosin- stained sections demonstrated irregular acanthosis and variable spongiosis. The stratum corneum was predominantly orthokeratotic with overlying psuedohyphae and yeast fungal elements (Figure 1). 

Hyperimmunoglobulinemia E syndrome (HIES), also known as hyper-IgE syndrome or Job syndrome, is a rare immunodeficiency disorder characterized by an eczematous dermatitis-like rash, recurrent skin and lung abscesses, eosinophilia, and elevated serum IgE. Facial asymmetry, prominent forehead, deep-set eyes, broad nose, and roughened facial skin with large pores are characteristic of the sporadic and autosomal-recessive forms. Other common findings include retained primary teeth, hyperextensible joints, and recurrent mucocutaneous candidiasis.¹ 

Although autosomal-dominant and autosomal-recessive inheritance patterns exist, sporadic mutations are the most common cause of HIES.² Several genes have been implicated depending on the inheritance pattern. The majority of autosomal-dominant cases are associated with inactivating STAT3 (signal transducer and activator of transcription 3) mutations, whereas the majority of autosomal-recessive cases are associated with inactivating DOCK8 (dedicator of cytokinesis 8) mutations.¹ Ultimately, all of these mutations lead to an impaired helper T cell (T_H17) response, which is crucial for clearing fungal and extracellular bacterial infections.³  

Skin eruptions typically are the first manifestation of HIES; they appear within the first week to month of life as papulopustular eruptions on the face and scalp and rapidly generalize to the rest of the body, favoring the shoulders, arms, chest, and buttocks. The pustules then coalesce into crusted plaques that resemble atopic dermatitis, frequently with superimposed Staphylococcus aureus infection. On microscopy, the pustules are folliculocentric and often contain eosinophils, whereas the plaques may contain intraepidermal collections of eosinophils.¹ 

Mucocutaneous candidiasis is seen in approximately 60% of HIES cases and is closely linked to STAT3 inactivating mutations.³ Histologically, there is marked acanthosis with neutrophil exocytosis and abundant yeast and pseudohyphal forms within the stratum corneum (Figure 2).⁴ Cutaneous candidal infections typically require both oral and topical antifungal agents to clear the infection.³ Most cases of mucocutaneous candidiasis are caused by Candida albicans; however, other known culprits include Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei.^5,6 Of note, species identification and antifungal susceptibility studies may be useful in refractory cases, especially with C glabrata, which is known to acquire resistance to azoles, such as fluconazole, with emerging resistance to echinocandins.⁶  

The differential diagnosis of this groin eruption included Hailey-Hailey disease; pemphigus vegetans, Hallopeau type; tinea cruris; and inverse psoriasis. Hailey-Hailey disease can be complicated by a superimposed candidal infection with similar clinical features, and biopsy may be required for definitive diagnosis. Hailey-Hailey disease typically presents with macerated fissured plaques that resemble macerated tissue paper with red fissures (Figure 3). Biopsy confirms full-thickness acantholysis resembling a dilapidated brick wall with minimal dyskeratosis.¹ Pemphigus vegetans is a localized variant of pemphigus vulgaris with a predilection for flexural surfaces. The lesions progress to vegetating erosive plaques.⁴ The Hallopeau type often is studded with pustules and typically remains more localized than the Neumann type. Direct immunofluorescence demonstrates intercellular deposition of IgG and C3, and routine sections characteristically show pseudoepitheliomatous hyperplasia with intraepidermal eosinophilic microabscesses.^1,4 Tinea cruris is characterized by erythematous annular lesions with raised scaly borders spreading down the inner thighs.⁷ The epidermis is variably spongiotic with parakeratosis, and neutrophils often present in a layered stratum corneum with basketweave keratin above a layer of more compact and eosinophilic keratin. Fungal stains, such as periodic acid-Schiff, will highlight the fungal hyphae within the stratum corneum. The inguinal folds are a typical location for inverse psoriasis, which generally appears as thin, sharply demarcated, shiny red plaques with less scale than plaque psoriasis.¹ Psoriasiform hyperplasia with a diminished granular layer and tortuous papillary dermal vessels would be expected histologically.¹ 

The Diagnosis: Candidal Intertrigo  

The biopsy confirmed a diagnosis of severe hyperkeratotic candidal intertrigo with no evidence of Hailey-Hailey disease. Hematoxylin and eosin- stained sections demonstrated irregular acanthosis and variable spongiosis. The stratum corneum was predominantly orthokeratotic with overlying psuedohyphae and yeast fungal elements (Figure 1). 

Hyperimmunoglobulinemia E syndrome (HIES), also known as hyper-IgE syndrome or Job syndrome, is a rare immunodeficiency disorder characterized by an eczematous dermatitis-like rash, recurrent skin and lung abscesses, eosinophilia, and elevated serum IgE. Facial asymmetry, prominent forehead, deep-set eyes, broad nose, and roughened facial skin with large pores are characteristic of the sporadic and autosomal-recessive forms. Other common findings include retained primary teeth, hyperextensible joints, and recurrent mucocutaneous candidiasis.¹ 

Although autosomal-dominant and autosomal-recessive inheritance patterns exist, sporadic mutations are the most common cause of HIES.² Several genes have been implicated depending on the inheritance pattern. The majority of autosomal-dominant cases are associated with inactivating STAT3 (signal transducer and activator of transcription 3) mutations, whereas the majority of autosomal-recessive cases are associated with inactivating DOCK8 (dedicator of cytokinesis 8) mutations.¹ Ultimately, all of these mutations lead to an impaired helper T cell (T_H17) response, which is crucial for clearing fungal and extracellular bacterial infections.³  

Skin eruptions typically are the first manifestation of HIES; they appear within the first week to month of life as papulopustular eruptions on the face and scalp and rapidly generalize to the rest of the body, favoring the shoulders, arms, chest, and buttocks. The pustules then coalesce into crusted plaques that resemble atopic dermatitis, frequently with superimposed Staphylococcus aureus infection. On microscopy, the pustules are folliculocentric and often contain eosinophils, whereas the plaques may contain intraepidermal collections of eosinophils.¹ 

Mucocutaneous candidiasis is seen in approximately 60% of HIES cases and is closely linked to STAT3 inactivating mutations.³ Histologically, there is marked acanthosis with neutrophil exocytosis and abundant yeast and pseudohyphal forms within the stratum corneum (Figure 2).⁴ Cutaneous candidal infections typically require both oral and topical antifungal agents to clear the infection.³ Most cases of mucocutaneous candidiasis are caused by Candida albicans; however, other known culprits include Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei.^5,6 Of note, species identification and antifungal susceptibility studies may be useful in refractory cases, especially with C glabrata, which is known to acquire resistance to azoles, such as fluconazole, with emerging resistance to echinocandins.⁶  

The differential diagnosis of this groin eruption included Hailey-Hailey disease; pemphigus vegetans, Hallopeau type; tinea cruris; and inverse psoriasis. Hailey-Hailey disease can be complicated by a superimposed candidal infection with similar clinical features, and biopsy may be required for definitive diagnosis. Hailey-Hailey disease typically presents with macerated fissured plaques that resemble macerated tissue paper with red fissures (Figure 3). Biopsy confirms full-thickness acantholysis resembling a dilapidated brick wall with minimal dyskeratosis.¹ Pemphigus vegetans is a localized variant of pemphigus vulgaris with a predilection for flexural surfaces. The lesions progress to vegetating erosive plaques.⁴ The Hallopeau type often is studded with pustules and typically remains more localized than the Neumann type. Direct immunofluorescence demonstrates intercellular deposition of IgG and C3, and routine sections characteristically show pseudoepitheliomatous hyperplasia with intraepidermal eosinophilic microabscesses.^1,4 Tinea cruris is characterized by erythematous annular lesions with raised scaly borders spreading down the inner thighs.⁷ The epidermis is variably spongiotic with parakeratosis, and neutrophils often present in a layered stratum corneum with basketweave keratin above a layer of more compact and eosinophilic keratin. Fungal stains, such as periodic acid-Schiff, will highlight the fungal hyphae within the stratum corneum. The inguinal folds are a typical location for inverse psoriasis, which generally appears as thin, sharply demarcated, shiny red plaques with less scale than plaque psoriasis.¹ Psoriasiform hyperplasia with a diminished granular layer and tortuous papillary dermal vessels would be expected histologically.¹ 

The Diagnosis: Candidal Intertrigo  

The biopsy confirmed a diagnosis of severe hyperkeratotic candidal intertrigo with no evidence of Hailey-Hailey disease. Hematoxylin and eosin- stained sections demonstrated irregular acanthosis and variable spongiosis. The stratum corneum was predominantly orthokeratotic with overlying psuedohyphae and yeast fungal elements (Figure 1). 

Hyperimmunoglobulinemia E syndrome (HIES), also known as hyper-IgE syndrome or Job syndrome, is a rare immunodeficiency disorder characterized by an eczematous dermatitis-like rash, recurrent skin and lung abscesses, eosinophilia, and elevated serum IgE. Facial asymmetry, prominent forehead, deep-set eyes, broad nose, and roughened facial skin with large pores are characteristic of the sporadic and autosomal-recessive forms. Other common findings include retained primary teeth, hyperextensible joints, and recurrent mucocutaneous candidiasis.¹ 

Although autosomal-dominant and autosomal-recessive inheritance patterns exist, sporadic mutations are the most common cause of HIES.² Several genes have been implicated depending on the inheritance pattern. The majority of autosomal-dominant cases are associated with inactivating STAT3 (signal transducer and activator of transcription 3) mutations, whereas the majority of autosomal-recessive cases are associated with inactivating DOCK8 (dedicator of cytokinesis 8) mutations.¹ Ultimately, all of these mutations lead to an impaired helper T cell (T_H17) response, which is crucial for clearing fungal and extracellular bacterial infections.³  

Skin eruptions typically are the first manifestation of HIES; they appear within the first week to month of life as papulopustular eruptions on the face and scalp and rapidly generalize to the rest of the body, favoring the shoulders, arms, chest, and buttocks. The pustules then coalesce into crusted plaques that resemble atopic dermatitis, frequently with superimposed Staphylococcus aureus infection. On microscopy, the pustules are folliculocentric and often contain eosinophils, whereas the plaques may contain intraepidermal collections of eosinophils.¹ 

Mucocutaneous candidiasis is seen in approximately 60% of HIES cases and is closely linked to STAT3 inactivating mutations.³ Histologically, there is marked acanthosis with neutrophil exocytosis and abundant yeast and pseudohyphal forms within the stratum corneum (Figure 2).⁴ Cutaneous candidal infections typically require both oral and topical antifungal agents to clear the infection.³ Most cases of mucocutaneous candidiasis are caused by Candida albicans; however, other known culprits include Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei.^5,6 Of note, species identification and antifungal susceptibility studies may be useful in refractory cases, especially with C glabrata, which is known to acquire resistance to azoles, such as fluconazole, with emerging resistance to echinocandins.⁶  

The differential diagnosis of this groin eruption included Hailey-Hailey disease; pemphigus vegetans, Hallopeau type; tinea cruris; and inverse psoriasis. Hailey-Hailey disease can be complicated by a superimposed candidal infection with similar clinical features, and biopsy may be required for definitive diagnosis. Hailey-Hailey disease typically presents with macerated fissured plaques that resemble macerated tissue paper with red fissures (Figure 3). Biopsy confirms full-thickness acantholysis resembling a dilapidated brick wall with minimal dyskeratosis.¹ Pemphigus vegetans is a localized variant of pemphigus vulgaris with a predilection for flexural surfaces. The lesions progress to vegetating erosive plaques.⁴ The Hallopeau type often is studded with pustules and typically remains more localized than the Neumann type. Direct immunofluorescence demonstrates intercellular deposition of IgG and C3, and routine sections characteristically show pseudoepitheliomatous hyperplasia with intraepidermal eosinophilic microabscesses.^1,4 Tinea cruris is characterized by erythematous annular lesions with raised scaly borders spreading down the inner thighs.⁷ The epidermis is variably spongiotic with parakeratosis, and neutrophils often present in a layered stratum corneum with basketweave keratin above a layer of more compact and eosinophilic keratin. Fungal stains, such as periodic acid-Schiff, will highlight the fungal hyphae within the stratum corneum. The inguinal folds are a typical location for inverse psoriasis, which generally appears as thin, sharply demarcated, shiny red plaques with less scale than plaque psoriasis.¹ Psoriasiform hyperplasia with a diminished granular layer and tortuous papillary dermal vessels would be expected histologically.¹ 

The Diagnosis: Eosinophilic Folliculitis 

A  shave biopsy specimen of an intact pustule on the left side of the chest was obtained. Histopathologic examination revealed follicular inflammation with copious eosinophils (Figure, A and B). Based on the histopathology and clinical presentation, a diagnosis of human immunodeficiency virus (HIV)-associated eosinophilic folliculitis (EF) was made. 

The patient was started on triamcinolone ointment 0.1% twice daily to active lesions, oral cetirizine 10 mg in the morning, and oral hydroxyzine 25 mg at bedtime. Laboratory evaluation at the time of diagnosis showed eosinophilia with a peripheral blood eosinophil count of 0.5 K/μL (reference range, 0.03–0.48 K/μL).

Human immunodeficiency virus-associated EF is a pruritic follicular eruption that occurs in HIV-positive individuals with advanced disease. Clinically, it is characterized by intermittent, urticarial, red or flesh-colored, 2- to 5-mm papules with sparse pustules involving the head, neck, arms, and upper trunk.^1,2 The cardinal clinical feature of the disorder is intense pruritus, with overlying crusts and excoriations present on physical examination.³  

Patients usually have a CD4 count of less than 250 cells/mm³.^2,3 Patients with HIV can develop an exacerbation of EF in the first 3 to 6 months after initiating antiretroviral therapy. This clinical pattern is believed to be due to the reconstituted immune system and increased circulation of inflammatory cells.⁴ Peripheral eosinophilia and elevated serum IgE levels are found in 25% to 50% of patients with HIV-associated EF.^2,3  

Clinically, the differential diagnosis of intensely pruritic papules with excoriations should include scabies.³ Other diagnoses to consider include opportunistic infections and papular urticaria.⁵ Acne vulgaris and Demodex folliculitis also may present with lesions similar to HIV-associated EF; however, these lesions tend not to be as intensely pruritic.^1,5 

The etiology of HIV-associated EF is unknown.³ One proposed mechanism involves a hypersensitivity reaction to Pityrosporum or Demodex mite fragments, as evidenced by studies that found fragments of these microorganisms in biopsied lesions of HIV-associated EF.^3,6 In our patient's histopathology, it was noted that the afflicted hair follicle held a single Demodex mite (Figure, C). 

The histopathology is characterized by a perifollicular inflammatory infiltrate of eosinophils and CD8+ lymphocytes with areas of sebaceous lysis.^3,6 Spongiosis of the follicular epithelium is seen in early lesions of HIV-associated EF.⁶ 

The first-line treatment of HIV-associated EF includes antiretroviral therapy with topical steroids and antihistamines. Human immunodeficiency virus-associated EF improves as CD4 helper T-cell counts rise above 250 cells/mm³ with continued antiretroviral therapy, though it initially can cause a flare of the condition.⁴ High-potency steroids and antihistamines are added during this period to treat the severe pruritus.^1,7 In particular, daily cetirizine has been shown to be effective, which may be due to its ability to block eosinophil migration in addition to H1-receptor antagonist properties.^3,7 

Various alternative therapies have been described in case reports and case series; however, there have been no controlled studies comparing therapies. Phototherapy with UVB light 3 times weekly for 3 to 6 weeks has been effective and curative in recalcitrant cases.⁷ Other frequently used treatments include oral metronidazole, oral itraconazole, and permethrin cream 5%. The effectiveness of the latter 2 treatments is believed to be related to the proposed role of Pityrosporum and Demodex in the pathogenesis.³  

Acknowledgment
The authors thank Garth Fraga, MD (Kansas City, Kansas), for his help compiling the histopathological images and their diagnostic descriptions.  
 

The Diagnosis: Eosinophilic Folliculitis 

A  shave biopsy specimen of an intact pustule on the left side of the chest was obtained. Histopathologic examination revealed follicular inflammation with copious eosinophils (Figure, A and B). Based on the histopathology and clinical presentation, a diagnosis of human immunodeficiency virus (HIV)-associated eosinophilic folliculitis (EF) was made. 

The patient was started on triamcinolone ointment 0.1% twice daily to active lesions, oral cetirizine 10 mg in the morning, and oral hydroxyzine 25 mg at bedtime. Laboratory evaluation at the time of diagnosis showed eosinophilia with a peripheral blood eosinophil count of 0.5 K/μL (reference range, 0.03–0.48 K/μL).

Human immunodeficiency virus-associated EF is a pruritic follicular eruption that occurs in HIV-positive individuals with advanced disease. Clinically, it is characterized by intermittent, urticarial, red or flesh-colored, 2- to 5-mm papules with sparse pustules involving the head, neck, arms, and upper trunk.^1,2 The cardinal clinical feature of the disorder is intense pruritus, with overlying crusts and excoriations present on physical examination.³  

Patients usually have a CD4 count of less than 250 cells/mm³.^2,3 Patients with HIV can develop an exacerbation of EF in the first 3 to 6 months after initiating antiretroviral therapy. This clinical pattern is believed to be due to the reconstituted immune system and increased circulation of inflammatory cells.⁴ Peripheral eosinophilia and elevated serum IgE levels are found in 25% to 50% of patients with HIV-associated EF.^2,3  

Clinically, the differential diagnosis of intensely pruritic papules with excoriations should include scabies.³ Other diagnoses to consider include opportunistic infections and papular urticaria.⁵ Acne vulgaris and Demodex folliculitis also may present with lesions similar to HIV-associated EF; however, these lesions tend not to be as intensely pruritic.^1,5 

The etiology of HIV-associated EF is unknown.³ One proposed mechanism involves a hypersensitivity reaction to Pityrosporum or Demodex mite fragments, as evidenced by studies that found fragments of these microorganisms in biopsied lesions of HIV-associated EF.^3,6 In our patient's histopathology, it was noted that the afflicted hair follicle held a single Demodex mite (Figure, C). 

The histopathology is characterized by a perifollicular inflammatory infiltrate of eosinophils and CD8+ lymphocytes with areas of sebaceous lysis.^3,6 Spongiosis of the follicular epithelium is seen in early lesions of HIV-associated EF.⁶ 

The first-line treatment of HIV-associated EF includes antiretroviral therapy with topical steroids and antihistamines. Human immunodeficiency virus-associated EF improves as CD4 helper T-cell counts rise above 250 cells/mm³ with continued antiretroviral therapy, though it initially can cause a flare of the condition.⁴ High-potency steroids and antihistamines are added during this period to treat the severe pruritus.^1,7 In particular, daily cetirizine has been shown to be effective, which may be due to its ability to block eosinophil migration in addition to H1-receptor antagonist properties.^3,7 

Various alternative therapies have been described in case reports and case series; however, there have been no controlled studies comparing therapies. Phototherapy with UVB light 3 times weekly for 3 to 6 weeks has been effective and curative in recalcitrant cases.⁷ Other frequently used treatments include oral metronidazole, oral itraconazole, and permethrin cream 5%. The effectiveness of the latter 2 treatments is believed to be related to the proposed role of Pityrosporum and Demodex in the pathogenesis.³  

Acknowledgment
The authors thank Garth Fraga, MD (Kansas City, Kansas), for his help compiling the histopathological images and their diagnostic descriptions.  
 

The Diagnosis: Eosinophilic Folliculitis 

A  shave biopsy specimen of an intact pustule on the left side of the chest was obtained. Histopathologic examination revealed follicular inflammation with copious eosinophils (Figure, A and B). Based on the histopathology and clinical presentation, a diagnosis of human immunodeficiency virus (HIV)-associated eosinophilic folliculitis (EF) was made. 

The patient was started on triamcinolone ointment 0.1% twice daily to active lesions, oral cetirizine 10 mg in the morning, and oral hydroxyzine 25 mg at bedtime. Laboratory evaluation at the time of diagnosis showed eosinophilia with a peripheral blood eosinophil count of 0.5 K/μL (reference range, 0.03–0.48 K/μL).

Human immunodeficiency virus-associated EF is a pruritic follicular eruption that occurs in HIV-positive individuals with advanced disease. Clinically, it is characterized by intermittent, urticarial, red or flesh-colored, 2- to 5-mm papules with sparse pustules involving the head, neck, arms, and upper trunk.^1,2 The cardinal clinical feature of the disorder is intense pruritus, with overlying crusts and excoriations present on physical examination.³  

Patients usually have a CD4 count of less than 250 cells/mm³.^2,3 Patients with HIV can develop an exacerbation of EF in the first 3 to 6 months after initiating antiretroviral therapy. This clinical pattern is believed to be due to the reconstituted immune system and increased circulation of inflammatory cells.⁴ Peripheral eosinophilia and elevated serum IgE levels are found in 25% to 50% of patients with HIV-associated EF.^2,3  

Clinically, the differential diagnosis of intensely pruritic papules with excoriations should include scabies.³ Other diagnoses to consider include opportunistic infections and papular urticaria.⁵ Acne vulgaris and Demodex folliculitis also may present with lesions similar to HIV-associated EF; however, these lesions tend not to be as intensely pruritic.^1,5 

The etiology of HIV-associated EF is unknown.³ One proposed mechanism involves a hypersensitivity reaction to Pityrosporum or Demodex mite fragments, as evidenced by studies that found fragments of these microorganisms in biopsied lesions of HIV-associated EF.^3,6 In our patient's histopathology, it was noted that the afflicted hair follicle held a single Demodex mite (Figure, C). 

The histopathology is characterized by a perifollicular inflammatory infiltrate of eosinophils and CD8+ lymphocytes with areas of sebaceous lysis.^3,6 Spongiosis of the follicular epithelium is seen in early lesions of HIV-associated EF.⁶ 

The first-line treatment of HIV-associated EF includes antiretroviral therapy with topical steroids and antihistamines. Human immunodeficiency virus-associated EF improves as CD4 helper T-cell counts rise above 250 cells/mm³ with continued antiretroviral therapy, though it initially can cause a flare of the condition.⁴ High-potency steroids and antihistamines are added during this period to treat the severe pruritus.^1,7 In particular, daily cetirizine has been shown to be effective, which may be due to its ability to block eosinophil migration in addition to H1-receptor antagonist properties.^3,7 

Various alternative therapies have been described in case reports and case series; however, there have been no controlled studies comparing therapies. Phototherapy with UVB light 3 times weekly for 3 to 6 weeks has been effective and curative in recalcitrant cases.⁷ Other frequently used treatments include oral metronidazole, oral itraconazole, and permethrin cream 5%. The effectiveness of the latter 2 treatments is believed to be related to the proposed role of Pityrosporum and Demodex in the pathogenesis.³  

Acknowledgment
The authors thank Garth Fraga, MD (Kansas City, Kansas), for his help compiling the histopathological images and their diagnostic descriptions.  
 

The Diagnosis: Majocchi Granuloma 

Majocchi granuloma (MG) is a dermatophytic infection that reveals hyphal elements within the cornified cells of follicles and most commonly is caused by Trichophyton rubrum. However, occasionally other Trichophyton, Trichosporon, and Aspergillus species are involved.¹  

There typically are 2 forms of MG: (1) the small perifollicular papular form that usually is localized to the dermis and occurs in immunocompetent individuals, and (2) a deep form featuring subcutaneous plaques and nodules that generally occur on the hair-bearing surfaces in immunosuppressed hosts.² Majocchi granuloma also commonly occurs from the use of potent topical steroids on unsuspected tinea.³  

Histopathologically, MG generally presents as granulomatous inflammation with perifollicular neutrophilic infiltration. This polymorphonuclear cell infiltrate was visible clinically as a single pustule overlying the nodular plaque, a clue appreciable only on close inspection. Histopathologic examination revealed segmented branching filaments present within cornified elements of a follicle (Figure). Notably, potassium hydroxide (KOH) preparations are unreliable diagnostic aids in MG, as evidenced by the 2 negative KOH preparations in this case. According to Chou and Hsu,⁴ because KOH preparation can only detect fungi located in the stratum corneum, the result may be negative for MG due to deeper invasion of the fungi into the dermal follicular component. In fact, KOH preparations of MG may reveal no hyphae in 23.3% of cases.²  

The initiating factor in MG is not entirely known but is thought to be physical trauma that either directly or indirectly leads to follicle disruption and passive introduction of the organism into the dermis (eg, traumatic implantation via gardening or other recreational activities).² Other proposed mechanisms include the presentation of the membrane-associated ATP-binding cassette transporter on the surface of T rubrum.¹ Dermatophytes evade the host immune system through a variety of mechanisms: (1) cell wall glycoproteins, (2) release of anti-inflammatory cytokines, and (3) generation of immunosuppressive regulatory T cells.¹ 

Collectively, the clinical and histopathologic findings distinguish MG from other cutaneous conditions. Sporotrichosis, a granulomatous infection caused by Sporothrix schenckii, typically is found in tropical regions of the world and often is associated with floriculture.⁵ Sporotrichosis initially presents in a subcutaneous papulonodular form, but unlike MG, it later ulcerates and progresses along adjacent lymphatic chains.⁵ Pathology of sporotrichosis exhibits pseudoepitheliomatous hyperplasia with granulomas, possible foci of suppuration, and yeastlike forms called cigar bodies. Chromoblastomycosis clinically is defined by tumorlike lesions on the skin including verrucous, nodular, or scarlike plaques and typically is associated with traumatic injury and implantation of the microorganism. Histologically, chromoblastomycosis demonstrates pseudoepitheliomatous hyperplasia with granulomas and characteristic darkly pigmented, thick-walled sclerotic cells called Medlar bodies.⁶Mycobacterium marinum is one cause of nontuberculous mycobacterial skin infections in humans. Clinically, M marinum is associated with improper hygiene techniques and contact with fish tanks and other aqueous environments. Mycobacterium marinum can present histopathologically as early neutrophilic infiltration or late dermal granulomatous inflammation.⁷ Acid-fast bacilli typically are scant, leaving the diagnosis best secured via polymerase chain reaction assay. Nodular Kaposi sarcoma (KS) can present as a dusky nodular plaque on an acral surface but typically is seen in patients with underlying human immunodeficiency virus/AIDS or other immunosuppressive conditions. The pathology for KS shows a proliferation of human herpes virus 8-positive spindle cells with slitlike spaces containing red blood cells instead of granulomatous inflammation. 

Treatment regimens with topical corticosteroids can exacerbate the infection due to local suppression of cell-mediated immunity.⁸ In these scenarios, fungal infection is suspected, and systemic antifungals such as ketoconazole; itraconazole; or terbinafine, which has become the mainstay, are prescribed. Resolution of the infection with these medications usually is seen after 4 weeks.² 

A diagnosis of MG can be elusive and often may take multiple visits. Clinicians should note that MG could demonstrate repeated false-negative KOH preparations; therefore, these tests should not be relied on as the sole determination of a diagnosis. Although chromoblastomycosis, sporotrichosis, nodular KS, and infection with M marinum may all present as nodular plaques with granulomatous pathology, a follicular pustule may be a clinical clue to MG, as its mimics typically lack folliculocentric neutrophils.

The Diagnosis: Majocchi Granuloma 

Majocchi granuloma (MG) is a dermatophytic infection that reveals hyphal elements within the cornified cells of follicles and most commonly is caused by Trichophyton rubrum. However, occasionally other Trichophyton, Trichosporon, and Aspergillus species are involved.¹  

There typically are 2 forms of MG: (1) the small perifollicular papular form that usually is localized to the dermis and occurs in immunocompetent individuals, and (2) a deep form featuring subcutaneous plaques and nodules that generally occur on the hair-bearing surfaces in immunosuppressed hosts.² Majocchi granuloma also commonly occurs from the use of potent topical steroids on unsuspected tinea.³  

Histopathologically, MG generally presents as granulomatous inflammation with perifollicular neutrophilic infiltration. This polymorphonuclear cell infiltrate was visible clinically as a single pustule overlying the nodular plaque, a clue appreciable only on close inspection. Histopathologic examination revealed segmented branching filaments present within cornified elements of a follicle (Figure). Notably, potassium hydroxide (KOH) preparations are unreliable diagnostic aids in MG, as evidenced by the 2 negative KOH preparations in this case. According to Chou and Hsu,⁴ because KOH preparation can only detect fungi located in the stratum corneum, the result may be negative for MG due to deeper invasion of the fungi into the dermal follicular component. In fact, KOH preparations of MG may reveal no hyphae in 23.3% of cases.²  

The initiating factor in MG is not entirely known but is thought to be physical trauma that either directly or indirectly leads to follicle disruption and passive introduction of the organism into the dermis (eg, traumatic implantation via gardening or other recreational activities).² Other proposed mechanisms include the presentation of the membrane-associated ATP-binding cassette transporter on the surface of T rubrum.¹ Dermatophytes evade the host immune system through a variety of mechanisms: (1) cell wall glycoproteins, (2) release of anti-inflammatory cytokines, and (3) generation of immunosuppressive regulatory T cells.¹ 

Collectively, the clinical and histopathologic findings distinguish MG from other cutaneous conditions. Sporotrichosis, a granulomatous infection caused by Sporothrix schenckii, typically is found in tropical regions of the world and often is associated with floriculture.⁵ Sporotrichosis initially presents in a subcutaneous papulonodular form, but unlike MG, it later ulcerates and progresses along adjacent lymphatic chains.⁵ Pathology of sporotrichosis exhibits pseudoepitheliomatous hyperplasia with granulomas, possible foci of suppuration, and yeastlike forms called cigar bodies. Chromoblastomycosis clinically is defined by tumorlike lesions on the skin including verrucous, nodular, or scarlike plaques and typically is associated with traumatic injury and implantation of the microorganism. Histologically, chromoblastomycosis demonstrates pseudoepitheliomatous hyperplasia with granulomas and characteristic darkly pigmented, thick-walled sclerotic cells called Medlar bodies.⁶Mycobacterium marinum is one cause of nontuberculous mycobacterial skin infections in humans. Clinically, M marinum is associated with improper hygiene techniques and contact with fish tanks and other aqueous environments. Mycobacterium marinum can present histopathologically as early neutrophilic infiltration or late dermal granulomatous inflammation.⁷ Acid-fast bacilli typically are scant, leaving the diagnosis best secured via polymerase chain reaction assay. Nodular Kaposi sarcoma (KS) can present as a dusky nodular plaque on an acral surface but typically is seen in patients with underlying human immunodeficiency virus/AIDS or other immunosuppressive conditions. The pathology for KS shows a proliferation of human herpes virus 8-positive spindle cells with slitlike spaces containing red blood cells instead of granulomatous inflammation. 

Treatment regimens with topical corticosteroids can exacerbate the infection due to local suppression of cell-mediated immunity.⁸ In these scenarios, fungal infection is suspected, and systemic antifungals such as ketoconazole; itraconazole; or terbinafine, which has become the mainstay, are prescribed. Resolution of the infection with these medications usually is seen after 4 weeks.² 

A diagnosis of MG can be elusive and often may take multiple visits. Clinicians should note that MG could demonstrate repeated false-negative KOH preparations; therefore, these tests should not be relied on as the sole determination of a diagnosis. Although chromoblastomycosis, sporotrichosis, nodular KS, and infection with M marinum may all present as nodular plaques with granulomatous pathology, a follicular pustule may be a clinical clue to MG, as its mimics typically lack folliculocentric neutrophils.

The Diagnosis: Majocchi Granuloma 

Majocchi granuloma (MG) is a dermatophytic infection that reveals hyphal elements within the cornified cells of follicles and most commonly is caused by Trichophyton rubrum. However, occasionally other Trichophyton, Trichosporon, and Aspergillus species are involved.¹  

There typically are 2 forms of MG: (1) the small perifollicular papular form that usually is localized to the dermis and occurs in immunocompetent individuals, and (2) a deep form featuring subcutaneous plaques and nodules that generally occur on the hair-bearing surfaces in immunosuppressed hosts.² Majocchi granuloma also commonly occurs from the use of potent topical steroids on unsuspected tinea.³  

Histopathologically, MG generally presents as granulomatous inflammation with perifollicular neutrophilic infiltration. This polymorphonuclear cell infiltrate was visible clinically as a single pustule overlying the nodular plaque, a clue appreciable only on close inspection. Histopathologic examination revealed segmented branching filaments present within cornified elements of a follicle (Figure). Notably, potassium hydroxide (KOH) preparations are unreliable diagnostic aids in MG, as evidenced by the 2 negative KOH preparations in this case. According to Chou and Hsu,⁴ because KOH preparation can only detect fungi located in the stratum corneum, the result may be negative for MG due to deeper invasion of the fungi into the dermal follicular component. In fact, KOH preparations of MG may reveal no hyphae in 23.3% of cases.²  

The initiating factor in MG is not entirely known but is thought to be physical trauma that either directly or indirectly leads to follicle disruption and passive introduction of the organism into the dermis (eg, traumatic implantation via gardening or other recreational activities).² Other proposed mechanisms include the presentation of the membrane-associated ATP-binding cassette transporter on the surface of T rubrum.¹ Dermatophytes evade the host immune system through a variety of mechanisms: (1) cell wall glycoproteins, (2) release of anti-inflammatory cytokines, and (3) generation of immunosuppressive regulatory T cells.¹ 

Collectively, the clinical and histopathologic findings distinguish MG from other cutaneous conditions. Sporotrichosis, a granulomatous infection caused by Sporothrix schenckii, typically is found in tropical regions of the world and often is associated with floriculture.⁵ Sporotrichosis initially presents in a subcutaneous papulonodular form, but unlike MG, it later ulcerates and progresses along adjacent lymphatic chains.⁵ Pathology of sporotrichosis exhibits pseudoepitheliomatous hyperplasia with granulomas, possible foci of suppuration, and yeastlike forms called cigar bodies. Chromoblastomycosis clinically is defined by tumorlike lesions on the skin including verrucous, nodular, or scarlike plaques and typically is associated with traumatic injury and implantation of the microorganism. Histologically, chromoblastomycosis demonstrates pseudoepitheliomatous hyperplasia with granulomas and characteristic darkly pigmented, thick-walled sclerotic cells called Medlar bodies.⁶Mycobacterium marinum is one cause of nontuberculous mycobacterial skin infections in humans. Clinically, M marinum is associated with improper hygiene techniques and contact with fish tanks and other aqueous environments. Mycobacterium marinum can present histopathologically as early neutrophilic infiltration or late dermal granulomatous inflammation.⁷ Acid-fast bacilli typically are scant, leaving the diagnosis best secured via polymerase chain reaction assay. Nodular Kaposi sarcoma (KS) can present as a dusky nodular plaque on an acral surface but typically is seen in patients with underlying human immunodeficiency virus/AIDS or other immunosuppressive conditions. The pathology for KS shows a proliferation of human herpes virus 8-positive spindle cells with slitlike spaces containing red blood cells instead of granulomatous inflammation. 

Treatment regimens with topical corticosteroids can exacerbate the infection due to local suppression of cell-mediated immunity.⁸ In these scenarios, fungal infection is suspected, and systemic antifungals such as ketoconazole; itraconazole; or terbinafine, which has become the mainstay, are prescribed. Resolution of the infection with these medications usually is seen after 4 weeks.² 

A diagnosis of MG can be elusive and often may take multiple visits. Clinicians should note that MG could demonstrate repeated false-negative KOH preparations; therefore, these tests should not be relied on as the sole determination of a diagnosis. Although chromoblastomycosis, sporotrichosis, nodular KS, and infection with M marinum may all present as nodular plaques with granulomatous pathology, a follicular pustule may be a clinical clue to MG, as its mimics typically lack folliculocentric neutrophils.

The Diagnosis: Papuloerythroderma of Ofuji 

The patient presented with a characteristic finding of skinfold sparing, known as the "deck-chair sign" (Figure 1).¹ A repeat biopsy at our institution revealed a dermal perivascular and bandlike infiltrate with lymphocytes and occasional eosinophils (Figure 2). The epidermis showed mild spongiosis, lymphocytic exocytosis, and rare necrotic keratinocytes. A T-cell gene rearrangement assay was negative for a monoclonal population of T lymphocytes. Based on the clinical and histologic features, the diagnosis was most consistent with papuloerythroderma of Ofuji (PEO); however, a lymphoproliferative disorder needed to be excluded. Further workup included a peripheral smear, complete blood cell count with differential, comprehensive metabolic panel, IgE level, and hepatitis panel; all were normal, except for an elevated serum IgE level. Human immunodeficiency virus and age-appropriate malignancy screening were negative. The patient was prescribed betamethasone dipropionate cream 0.05% twice daily, which resulted in near-complete resolution of the rash and marked improvement in pruritus.

In 1984, PEO was described as an entity of generalized pruritic erythroderma characterized by flat-topped, red to brown, coalescing papules with sparing of the skinfolds, later coined the deck-chair sign.^1,2 Papuloerythroderma of Ofuji commonly presents in elderly Asian males with a male to female ratio of 4:1.³ Papuloerythroderma of Ofuji is a T cell-mediated skin disease; however, the etiology of the signature rash remains unclear. One explanation includes circulating factors in the skin that elicit an inflammatory response, which does not occur in areas of external pressure.³ The deck-chair sign may occur more frequently in elderly individuals due to increased skin laxity, which creates crease lines that are spared from rubbing and excoriations.⁴  

Although Ofuji et al² initially reported 4 idiopathic cases, subsequent authors described PEO in association with other conditions, including cutaneous T-cell lymphoma (CTCL) and atopic diathesis, and infections, as well as secondary to medications. Some authors have suggested that PEO may be an early variant of mycosis fungoides; therefore, physicians should monitor patients closely.^5-7 Maher et al⁶ commented that multiple causative factors including CTCL underlie the development of papuloerythroderma.  

In a review of PEO, Torchia et al³ proposed diagnostic criteria and an etiologic classification to address whether PEO represents an independent entity or an unusual manifestation of other dermatoses. They established 4 categories of papuloerythroderma--primary, secondary, papuloerythrodermalike CTCL, and pseudopapuloerythroderma--and proposed that primary PEO is a diagnosis of exclusion. If no secondary association is found, they proposed 10 criteria for primary PEO: 5 major criteria include coalescing flat-topped papules, the deck-chair sign, pruritus, histopathologic exclusion of diseases such as CTCL, and a negative workup to exclude other causes.³ In 2018, Maher et al⁶ recommended workup to rule out cutaneous malignancy, including skin biopsy, flow cytometry, Sézary cell count, T-cell rearrangement, lactate dehydrogenase, and human T-cell lymphotropic virus 1. The 5 minor criteria proposed by Torchia et al³ include age older than 55 years, male sex, eosinophilia, elevated IgE level, and lymphopenia. Our patient fulfilled all 5 major criteria and 3 minor criteria; eosinophilia and lymphopenia were absent.  

Clinically, PEO has been associated with the deck-chair sign, a pattern of selective sparing of skinfolds, including axillary, inguinal, submammary, and other flexural areas. Although the deck-chair sign was originally considered pathognomonic for PEO, this clinical pattern also has been observed in other entities, such as angioimmunoblastic lymphoma, cutaneous Waldenström macroglobulinemia, and acanthosis nigricans.^5,8,9  

Specific characteristics of the rash and certain clinical symptoms may help to distinguish the deck-chair sign of PEO from its other causes. Although malignant acanthosis nigricans may spare the skinfolds, lesions have a classic velvety thickening and brownish hyperpigmentation, which is not characteristic of the reddish brown, flat-topped papules of PEO.⁹ Pai et al⁵ described a patient with parthenium dermatitis presenting with the deck-chair sign that developed years after repeated exposure to the allergen. Our patient did not have a history of repeated episodes of allergic contact dermatitis. In addition, areas of sparing may mimic the appearance of pityriasis rubra pilaris. As in our patient, those with PEO generally lack the follicular hyperkeratotic papules, palmoplantar keratoderma, widespread orange-red erythema, and characteristic histopathologic finding of hyperkeratosis with alternating orthokeratosis and parakeratosis, allowing these entities to be easily distinguished in most instances.¹⁰ 

Histopathologically, primary PEO shows a nonspecific spongiotic dermatitis-like pattern characterized by slight epidermal hyperplasia with spongiosis and a predominantly perivascular dermal infiltrate with lymphocytes, histiocytes, and eosinophils.³ These histologic findings may at times show some overlap with CTCL, and therefore T-cell gene rearrangement and flow cytometry may be performed in those instances.⁶  

Treatment includes the management of any underlying condition causing the papuloerythroderma.^3,6 There are no large clinical trials of treatment options for primary PEO due to its rarity. Topical or systemic corticosteroids remain the mainstay of treatment.³ Alternative treatments used with variable success include phototherapy, interferon, etretinate, cyclosporine, and azathioprine.¹¹ Allegue et al¹¹ successfully used methotrexate to treat a patient with primary PEO and postulated that methotrexate may act through an immunosuppressive mechanism on activated T cells due to the involvement of helper T cells T_H2 and T_H22 in its pathogenesis. 

Although the cutaneous manifestations of PEO may respond well to topical steroids, it is important to consider the possible presence of an underlying malignancy and other associated systemic conditions.

The Diagnosis: Papuloerythroderma of Ofuji 

The patient presented with a characteristic finding of skinfold sparing, known as the "deck-chair sign" (Figure 1).¹ A repeat biopsy at our institution revealed a dermal perivascular and bandlike infiltrate with lymphocytes and occasional eosinophils (Figure 2). The epidermis showed mild spongiosis, lymphocytic exocytosis, and rare necrotic keratinocytes. A T-cell gene rearrangement assay was negative for a monoclonal population of T lymphocytes. Based on the clinical and histologic features, the diagnosis was most consistent with papuloerythroderma of Ofuji (PEO); however, a lymphoproliferative disorder needed to be excluded. Further workup included a peripheral smear, complete blood cell count with differential, comprehensive metabolic panel, IgE level, and hepatitis panel; all were normal, except for an elevated serum IgE level. Human immunodeficiency virus and age-appropriate malignancy screening were negative. The patient was prescribed betamethasone dipropionate cream 0.05% twice daily, which resulted in near-complete resolution of the rash and marked improvement in pruritus.

In 1984, PEO was described as an entity of generalized pruritic erythroderma characterized by flat-topped, red to brown, coalescing papules with sparing of the skinfolds, later coined the deck-chair sign.^1,2 Papuloerythroderma of Ofuji commonly presents in elderly Asian males with a male to female ratio of 4:1.³ Papuloerythroderma of Ofuji is a T cell-mediated skin disease; however, the etiology of the signature rash remains unclear. One explanation includes circulating factors in the skin that elicit an inflammatory response, which does not occur in areas of external pressure.³ The deck-chair sign may occur more frequently in elderly individuals due to increased skin laxity, which creates crease lines that are spared from rubbing and excoriations.⁴  

Although Ofuji et al² initially reported 4 idiopathic cases, subsequent authors described PEO in association with other conditions, including cutaneous T-cell lymphoma (CTCL) and atopic diathesis, and infections, as well as secondary to medications. Some authors have suggested that PEO may be an early variant of mycosis fungoides; therefore, physicians should monitor patients closely.^5-7 Maher et al⁶ commented that multiple causative factors including CTCL underlie the development of papuloerythroderma.  

In a review of PEO, Torchia et al³ proposed diagnostic criteria and an etiologic classification to address whether PEO represents an independent entity or an unusual manifestation of other dermatoses. They established 4 categories of papuloerythroderma--primary, secondary, papuloerythrodermalike CTCL, and pseudopapuloerythroderma--and proposed that primary PEO is a diagnosis of exclusion. If no secondary association is found, they proposed 10 criteria for primary PEO: 5 major criteria include coalescing flat-topped papules, the deck-chair sign, pruritus, histopathologic exclusion of diseases such as CTCL, and a negative workup to exclude other causes.³ In 2018, Maher et al⁶ recommended workup to rule out cutaneous malignancy, including skin biopsy, flow cytometry, Sézary cell count, T-cell rearrangement, lactate dehydrogenase, and human T-cell lymphotropic virus 1. The 5 minor criteria proposed by Torchia et al³ include age older than 55 years, male sex, eosinophilia, elevated IgE level, and lymphopenia. Our patient fulfilled all 5 major criteria and 3 minor criteria; eosinophilia and lymphopenia were absent.  

Clinically, PEO has been associated with the deck-chair sign, a pattern of selective sparing of skinfolds, including axillary, inguinal, submammary, and other flexural areas. Although the deck-chair sign was originally considered pathognomonic for PEO, this clinical pattern also has been observed in other entities, such as angioimmunoblastic lymphoma, cutaneous Waldenström macroglobulinemia, and acanthosis nigricans.^5,8,9  

Specific characteristics of the rash and certain clinical symptoms may help to distinguish the deck-chair sign of PEO from its other causes. Although malignant acanthosis nigricans may spare the skinfolds, lesions have a classic velvety thickening and brownish hyperpigmentation, which is not characteristic of the reddish brown, flat-topped papules of PEO.⁹ Pai et al⁵ described a patient with parthenium dermatitis presenting with the deck-chair sign that developed years after repeated exposure to the allergen. Our patient did not have a history of repeated episodes of allergic contact dermatitis. In addition, areas of sparing may mimic the appearance of pityriasis rubra pilaris. As in our patient, those with PEO generally lack the follicular hyperkeratotic papules, palmoplantar keratoderma, widespread orange-red erythema, and characteristic histopathologic finding of hyperkeratosis with alternating orthokeratosis and parakeratosis, allowing these entities to be easily distinguished in most instances.¹⁰ 

Histopathologically, primary PEO shows a nonspecific spongiotic dermatitis-like pattern characterized by slight epidermal hyperplasia with spongiosis and a predominantly perivascular dermal infiltrate with lymphocytes, histiocytes, and eosinophils.³ These histologic findings may at times show some overlap with CTCL, and therefore T-cell gene rearrangement and flow cytometry may be performed in those instances.⁶  

Treatment includes the management of any underlying condition causing the papuloerythroderma.^3,6 There are no large clinical trials of treatment options for primary PEO due to its rarity. Topical or systemic corticosteroids remain the mainstay of treatment.³ Alternative treatments used with variable success include phototherapy, interferon, etretinate, cyclosporine, and azathioprine.¹¹ Allegue et al¹¹ successfully used methotrexate to treat a patient with primary PEO and postulated that methotrexate may act through an immunosuppressive mechanism on activated T cells due to the involvement of helper T cells T_H2 and T_H22 in its pathogenesis. 

Although the cutaneous manifestations of PEO may respond well to topical steroids, it is important to consider the possible presence of an underlying malignancy and other associated systemic conditions.

The Diagnosis: Papuloerythroderma of Ofuji 

The patient presented with a characteristic finding of skinfold sparing, known as the "deck-chair sign" (Figure 1).¹ A repeat biopsy at our institution revealed a dermal perivascular and bandlike infiltrate with lymphocytes and occasional eosinophils (Figure 2). The epidermis showed mild spongiosis, lymphocytic exocytosis, and rare necrotic keratinocytes. A T-cell gene rearrangement assay was negative for a monoclonal population of T lymphocytes. Based on the clinical and histologic features, the diagnosis was most consistent with papuloerythroderma of Ofuji (PEO); however, a lymphoproliferative disorder needed to be excluded. Further workup included a peripheral smear, complete blood cell count with differential, comprehensive metabolic panel, IgE level, and hepatitis panel; all were normal, except for an elevated serum IgE level. Human immunodeficiency virus and age-appropriate malignancy screening were negative. The patient was prescribed betamethasone dipropionate cream 0.05% twice daily, which resulted in near-complete resolution of the rash and marked improvement in pruritus.

In 1984, PEO was described as an entity of generalized pruritic erythroderma characterized by flat-topped, red to brown, coalescing papules with sparing of the skinfolds, later coined the deck-chair sign.^1,2 Papuloerythroderma of Ofuji commonly presents in elderly Asian males with a male to female ratio of 4:1.³ Papuloerythroderma of Ofuji is a T cell-mediated skin disease; however, the etiology of the signature rash remains unclear. One explanation includes circulating factors in the skin that elicit an inflammatory response, which does not occur in areas of external pressure.³ The deck-chair sign may occur more frequently in elderly individuals due to increased skin laxity, which creates crease lines that are spared from rubbing and excoriations.⁴  

Although Ofuji et al² initially reported 4 idiopathic cases, subsequent authors described PEO in association with other conditions, including cutaneous T-cell lymphoma (CTCL) and atopic diathesis, and infections, as well as secondary to medications. Some authors have suggested that PEO may be an early variant of mycosis fungoides; therefore, physicians should monitor patients closely.^5-7 Maher et al⁶ commented that multiple causative factors including CTCL underlie the development of papuloerythroderma.  

In a review of PEO, Torchia et al³ proposed diagnostic criteria and an etiologic classification to address whether PEO represents an independent entity or an unusual manifestation of other dermatoses. They established 4 categories of papuloerythroderma--primary, secondary, papuloerythrodermalike CTCL, and pseudopapuloerythroderma--and proposed that primary PEO is a diagnosis of exclusion. If no secondary association is found, they proposed 10 criteria for primary PEO: 5 major criteria include coalescing flat-topped papules, the deck-chair sign, pruritus, histopathologic exclusion of diseases such as CTCL, and a negative workup to exclude other causes.³ In 2018, Maher et al⁶ recommended workup to rule out cutaneous malignancy, including skin biopsy, flow cytometry, Sézary cell count, T-cell rearrangement, lactate dehydrogenase, and human T-cell lymphotropic virus 1. The 5 minor criteria proposed by Torchia et al³ include age older than 55 years, male sex, eosinophilia, elevated IgE level, and lymphopenia. Our patient fulfilled all 5 major criteria and 3 minor criteria; eosinophilia and lymphopenia were absent.  

Clinically, PEO has been associated with the deck-chair sign, a pattern of selective sparing of skinfolds, including axillary, inguinal, submammary, and other flexural areas. Although the deck-chair sign was originally considered pathognomonic for PEO, this clinical pattern also has been observed in other entities, such as angioimmunoblastic lymphoma, cutaneous Waldenström macroglobulinemia, and acanthosis nigricans.^5,8,9  

Specific characteristics of the rash and certain clinical symptoms may help to distinguish the deck-chair sign of PEO from its other causes. Although malignant acanthosis nigricans may spare the skinfolds, lesions have a classic velvety thickening and brownish hyperpigmentation, which is not characteristic of the reddish brown, flat-topped papules of PEO.⁹ Pai et al⁵ described a patient with parthenium dermatitis presenting with the deck-chair sign that developed years after repeated exposure to the allergen. Our patient did not have a history of repeated episodes of allergic contact dermatitis. In addition, areas of sparing may mimic the appearance of pityriasis rubra pilaris. As in our patient, those with PEO generally lack the follicular hyperkeratotic papules, palmoplantar keratoderma, widespread orange-red erythema, and characteristic histopathologic finding of hyperkeratosis with alternating orthokeratosis and parakeratosis, allowing these entities to be easily distinguished in most instances.¹⁰ 

Histopathologically, primary PEO shows a nonspecific spongiotic dermatitis-like pattern characterized by slight epidermal hyperplasia with spongiosis and a predominantly perivascular dermal infiltrate with lymphocytes, histiocytes, and eosinophils.³ These histologic findings may at times show some overlap with CTCL, and therefore T-cell gene rearrangement and flow cytometry may be performed in those instances.⁶  

Treatment includes the management of any underlying condition causing the papuloerythroderma.^3,6 There are no large clinical trials of treatment options for primary PEO due to its rarity. Topical or systemic corticosteroids remain the mainstay of treatment.³ Alternative treatments used with variable success include phototherapy, interferon, etretinate, cyclosporine, and azathioprine.¹¹ Allegue et al¹¹ successfully used methotrexate to treat a patient with primary PEO and postulated that methotrexate may act through an immunosuppressive mechanism on activated T cells due to the involvement of helper T cells T_H2 and T_H22 in its pathogenesis. 

Although the cutaneous manifestations of PEO may respond well to topical steroids, it is important to consider the possible presence of an underlying malignancy and other associated systemic conditions.

The Diagnosis: Apocrine Hidrocystoma 

Histopathologic examination of one of the papules revealed cystic cavities located within the dermis (Figure 1) lined by a cuboidal epithelium demonstrating decapitation secretion (Figure 2), confirming the diagnosis of apocrine hidrocystomas. The presence of multiple lesions prompted further examination for an underlying genetic disorder; however, the patient's hair, nails, and teeth were normal. There also was no evidence of palmoplantar keratoderma or blaschkoid dermatosis. 

Hidrocystomas are benign cysts of the sudoriferous apparatus that can be subdivided based on histogenesis (apocrine vs eccrine) or lesion count (single vs multiple).¹ Multiple lesions may be associated with disorders of ectodermal dysplasia, including Goltz syndrome and Schopf-Schulz-Passarge syndrome. Apocrine hidrocystomas tend to present as solitary, translucent, flesh-colored to bluish facial papules, and the occurrence of multiple lesions is rare in contrast to its eccrine counterpart.² Various extrafacial sites have been described including the trunk, axillae, umbilicus, genitalia, and digits.³ Apocrine hidrocystomas do not demonstrate aggravation with exposure to heat, unlike their eccrine counterparts.² 

A review of 107 patients with 215 histologically proven hidrocystomas demonstrated a preponderance for women in their mid 50s; 74.8% of patients had unilateral disease, and 69.8% of all lesions affected either the lower eyelid or lateral canthus. Recurrence following conventional surgical excision was observed in 2.3% of lesions.¹ 

A review from Japan recounted an incidence of 5 cases per year from 1999 to 2003.⁴ Patients ranged in age from 30 to 70 years, but there was no gender predilection. Individual apocrine hidrocystomas were mostly less than 2 cm and varied from flesh colored to light red, brown, blue, or purple; 61% of lesions arose periorbitally. Within their cohort, patients with multiple lesions were uncommon, with only 2 cases presenting with 2 lesions simultaneously.⁴  

Apocrine hidrocystomas are thought to result from a cystic proliferation of the secretory component of apocrine sweat glands, though the exact pathogenesis still is unclear.³ Histologic features include a unilocular or multilocular cystic cavity within the dermis lined by columnar cells demonstrating decapitation secretion, followed by a peripheral rim of flattened myoepithelial cells. 

Treatment of apocrine hidrocystomas includes topical anticholinergics, surgical excision, electrodesiccation, 1450-nm diode or CO² lasers, and trichloroacetic acid.² The novel use of cryotherapy,⁵ botulinum toxin,² and intralesional injections of 50% glucose (as a sclerosant)⁶ also have been reported. Caution should be exercised when managing digital lesions, as digital papillary carcinoma has been described as a clinical and histopathologic mimicker.⁷ 

Lipoid proteinosis is a rare autosomal-recessive disorder. Cutaneous lesions manifest in 2 overlapping stages, typically within the first 2 years of life. The first stage consists of vesicles and hemorrhagic crusts on the face and extremities and intraorally, which may heal with scarring. In the second stage, the skin becomes diffusely thickened and waxy, with the appearance of papules, nodules, or plaques along the eyelid margins (moniliform blepharosis), face, axillae, or scrotum. Verrucous lesions also may develop on the knee or elbow extensors.⁸  

Lymphangioma circumscriptum represents microcystic lymphatic malformations that can arise anywhere on the skin or oral mucosa. They present as clusters of clear or hemorrhagic vesicles of variable size and number favoring the proximal extremities and chest. Histologically, dilated lymphatic channels are seen in the upper dermis.⁸  

Syringomas are common benign tumors of the sweat ducts characterized histologically by superficial dermal proliferations of small comma-shaped ducts set in a fibrotic stroma. Clinically, syringomas appear as small, firm, flesh-colored papules with a predilection for the periorbital area. An eruptive onset may be observed, most commonly affecting the trunk. Syringomas may be associated with Down syndrome, while the clear cell variant may be associated with diabetes mellitus.⁸    

Primary systemic amyloidosis may present with a variety of systemic manifestations. Skin involvement can present as waxy, translucent, or purpuric papulonodules or plaques characteristically affecting the periorbital region. Other mucocutaneous signs include macroglossia with or without translucent to hemorrhagic papulovesicles; bruising, especially on the eyelids, neck, axillae, or anogenital area; vesiculobullous skin lesions; or diffuse cutaneous infiltration imparting a sclerodermoid appearance.⁸

The Diagnosis: Apocrine Hidrocystoma 

Histopathologic examination of one of the papules revealed cystic cavities located within the dermis (Figure 1) lined by a cuboidal epithelium demonstrating decapitation secretion (Figure 2), confirming the diagnosis of apocrine hidrocystomas. The presence of multiple lesions prompted further examination for an underlying genetic disorder; however, the patient's hair, nails, and teeth were normal. There also was no evidence of palmoplantar keratoderma or blaschkoid dermatosis. 

Hidrocystomas are benign cysts of the sudoriferous apparatus that can be subdivided based on histogenesis (apocrine vs eccrine) or lesion count (single vs multiple).¹ Multiple lesions may be associated with disorders of ectodermal dysplasia, including Goltz syndrome and Schopf-Schulz-Passarge syndrome. Apocrine hidrocystomas tend to present as solitary, translucent, flesh-colored to bluish facial papules, and the occurrence of multiple lesions is rare in contrast to its eccrine counterpart.² Various extrafacial sites have been described including the trunk, axillae, umbilicus, genitalia, and digits.³ Apocrine hidrocystomas do not demonstrate aggravation with exposure to heat, unlike their eccrine counterparts.² 

A review of 107 patients with 215 histologically proven hidrocystomas demonstrated a preponderance for women in their mid 50s; 74.8% of patients had unilateral disease, and 69.8% of all lesions affected either the lower eyelid or lateral canthus. Recurrence following conventional surgical excision was observed in 2.3% of lesions.¹ 

A review from Japan recounted an incidence of 5 cases per year from 1999 to 2003.⁴ Patients ranged in age from 30 to 70 years, but there was no gender predilection. Individual apocrine hidrocystomas were mostly less than 2 cm and varied from flesh colored to light red, brown, blue, or purple; 61% of lesions arose periorbitally. Within their cohort, patients with multiple lesions were uncommon, with only 2 cases presenting with 2 lesions simultaneously.⁴  

Apocrine hidrocystomas are thought to result from a cystic proliferation of the secretory component of apocrine sweat glands, though the exact pathogenesis still is unclear.³ Histologic features include a unilocular or multilocular cystic cavity within the dermis lined by columnar cells demonstrating decapitation secretion, followed by a peripheral rim of flattened myoepithelial cells. 

Treatment of apocrine hidrocystomas includes topical anticholinergics, surgical excision, electrodesiccation, 1450-nm diode or CO² lasers, and trichloroacetic acid.² The novel use of cryotherapy,⁵ botulinum toxin,² and intralesional injections of 50% glucose (as a sclerosant)⁶ also have been reported. Caution should be exercised when managing digital lesions, as digital papillary carcinoma has been described as a clinical and histopathologic mimicker.⁷ 

Lipoid proteinosis is a rare autosomal-recessive disorder. Cutaneous lesions manifest in 2 overlapping stages, typically within the first 2 years of life. The first stage consists of vesicles and hemorrhagic crusts on the face and extremities and intraorally, which may heal with scarring. In the second stage, the skin becomes diffusely thickened and waxy, with the appearance of papules, nodules, or plaques along the eyelid margins (moniliform blepharosis), face, axillae, or scrotum. Verrucous lesions also may develop on the knee or elbow extensors.⁸  

Lymphangioma circumscriptum represents microcystic lymphatic malformations that can arise anywhere on the skin or oral mucosa. They present as clusters of clear or hemorrhagic vesicles of variable size and number favoring the proximal extremities and chest. Histologically, dilated lymphatic channels are seen in the upper dermis.⁸  

Syringomas are common benign tumors of the sweat ducts characterized histologically by superficial dermal proliferations of small comma-shaped ducts set in a fibrotic stroma. Clinically, syringomas appear as small, firm, flesh-colored papules with a predilection for the periorbital area. An eruptive onset may be observed, most commonly affecting the trunk. Syringomas may be associated with Down syndrome, while the clear cell variant may be associated with diabetes mellitus.⁸    

Primary systemic amyloidosis may present with a variety of systemic manifestations. Skin involvement can present as waxy, translucent, or purpuric papulonodules or plaques characteristically affecting the periorbital region. Other mucocutaneous signs include macroglossia with or without translucent to hemorrhagic papulovesicles; bruising, especially on the eyelids, neck, axillae, or anogenital area; vesiculobullous skin lesions; or diffuse cutaneous infiltration imparting a sclerodermoid appearance.⁸

The Diagnosis: Apocrine Hidrocystoma 

Histopathologic examination of one of the papules revealed cystic cavities located within the dermis (Figure 1) lined by a cuboidal epithelium demonstrating decapitation secretion (Figure 2), confirming the diagnosis of apocrine hidrocystomas. The presence of multiple lesions prompted further examination for an underlying genetic disorder; however, the patient's hair, nails, and teeth were normal. There also was no evidence of palmoplantar keratoderma or blaschkoid dermatosis. 

Hidrocystomas are benign cysts of the sudoriferous apparatus that can be subdivided based on histogenesis (apocrine vs eccrine) or lesion count (single vs multiple).¹ Multiple lesions may be associated with disorders of ectodermal dysplasia, including Goltz syndrome and Schopf-Schulz-Passarge syndrome. Apocrine hidrocystomas tend to present as solitary, translucent, flesh-colored to bluish facial papules, and the occurrence of multiple lesions is rare in contrast to its eccrine counterpart.² Various extrafacial sites have been described including the trunk, axillae, umbilicus, genitalia, and digits.³ Apocrine hidrocystomas do not demonstrate aggravation with exposure to heat, unlike their eccrine counterparts.² 

A review of 107 patients with 215 histologically proven hidrocystomas demonstrated a preponderance for women in their mid 50s; 74.8% of patients had unilateral disease, and 69.8% of all lesions affected either the lower eyelid or lateral canthus. Recurrence following conventional surgical excision was observed in 2.3% of lesions.¹ 

A review from Japan recounted an incidence of 5 cases per year from 1999 to 2003.⁴ Patients ranged in age from 30 to 70 years, but there was no gender predilection. Individual apocrine hidrocystomas were mostly less than 2 cm and varied from flesh colored to light red, brown, blue, or purple; 61% of lesions arose periorbitally. Within their cohort, patients with multiple lesions were uncommon, with only 2 cases presenting with 2 lesions simultaneously.⁴  

Apocrine hidrocystomas are thought to result from a cystic proliferation of the secretory component of apocrine sweat glands, though the exact pathogenesis still is unclear.³ Histologic features include a unilocular or multilocular cystic cavity within the dermis lined by columnar cells demonstrating decapitation secretion, followed by a peripheral rim of flattened myoepithelial cells. 

Treatment of apocrine hidrocystomas includes topical anticholinergics, surgical excision, electrodesiccation, 1450-nm diode or CO² lasers, and trichloroacetic acid.² The novel use of cryotherapy,⁵ botulinum toxin,² and intralesional injections of 50% glucose (as a sclerosant)⁶ also have been reported. Caution should be exercised when managing digital lesions, as digital papillary carcinoma has been described as a clinical and histopathologic mimicker.⁷ 

Lipoid proteinosis is a rare autosomal-recessive disorder. Cutaneous lesions manifest in 2 overlapping stages, typically within the first 2 years of life. The first stage consists of vesicles and hemorrhagic crusts on the face and extremities and intraorally, which may heal with scarring. In the second stage, the skin becomes diffusely thickened and waxy, with the appearance of papules, nodules, or plaques along the eyelid margins (moniliform blepharosis), face, axillae, or scrotum. Verrucous lesions also may develop on the knee or elbow extensors.⁸  

Lymphangioma circumscriptum represents microcystic lymphatic malformations that can arise anywhere on the skin or oral mucosa. They present as clusters of clear or hemorrhagic vesicles of variable size and number favoring the proximal extremities and chest. Histologically, dilated lymphatic channels are seen in the upper dermis.⁸  

Syringomas are common benign tumors of the sweat ducts characterized histologically by superficial dermal proliferations of small comma-shaped ducts set in a fibrotic stroma. Clinically, syringomas appear as small, firm, flesh-colored papules with a predilection for the periorbital area. An eruptive onset may be observed, most commonly affecting the trunk. Syringomas may be associated with Down syndrome, while the clear cell variant may be associated with diabetes mellitus.⁸    

Primary systemic amyloidosis may present with a variety of systemic manifestations. Skin involvement can present as waxy, translucent, or purpuric papulonodules or plaques characteristically affecting the periorbital region. Other mucocutaneous signs include macroglossia with or without translucent to hemorrhagic papulovesicles; bruising, especially on the eyelids, neck, axillae, or anogenital area; vesiculobullous skin lesions; or diffuse cutaneous infiltration imparting a sclerodermoid appearance.⁸