Abstract
We present a case of sarcoidosis in a herpetiform distribution localized to the forearms exhibiting histologic evidence of transepidermal elimination (TEE). A 41-year-old black female presented with a 6-month history of a pruritic rash involving the forearms. Triamcinolone ointment did not provide relief. Review of systems elicited a 3-month history of shortness of breath and cough. On examination, there were numerous well-defined erythematous dermal papulonodules in a herpetiform distribution with raised borders and depressed centers involving the extensor surfaces of the bilateral forearms, with some papules exhibiting a hyperkeratotic surface. Punch biopsy was performed, and histopathology showed pseudoepitheliomatous epidermal hyperplasia overlying a sarcoidal pattern nodular dermal granulomatous infiltrate. Granulomatous inflammation was transepidermally eliminated via an epithelial structure (hair follicle or epidermal reti). A diagnosis of perforating sarcoidosis was favored. Chest X-Ray revealed bilateral prominence suggestive of sarcoid-related hilar lymphadenopathy. Pulmonary function testing revealed an obstructive pattern. Serum angiotensin-converting enzyme activity was increased at 100 U/L. Pulmonology physicians involved in her care rendered a diagnosis of sarcoidosis stage I with lymphadenopathy, confirming the histopathologic diagnosis. Initial therapy with Hydroxychloroquine 200 mg twice daily and Clobetasol 0.05% cream did not provide improvement. After adding Methotrexate 10 mg weekly, the patient reported substantial improvement and her clinical lesions showed significant flattening. This is the first report of TEE in lesions of sarcoidosis in a herpetiform distribution localized to the forearms. Additionally, this case illustrates the importance of the dermatologists role in establishing a diagnosis of systemic sarcoidosis based on a patients cutaneous findings.Financial Disclosure:
No current or relevant financial relationships exist.