A man in his 30s with no relevant past medical history presented with an approximately 1-month history of diffuse, nonpruritic cutaneous lesions. Physical examination revealed numerous red-brown papules on the oral mucosa, glans, trunk, and bilateral upper extremities, sparing palmar and plantar surfaces ( Fig. 1a,b). Some lesions developed ulcerated necrotic centers with thick crust. All other findings of his examination were within normal limits. There was no lymphadenopathy noted.
Histopathological findings and clinical courseHistopathologic examination demonstrated focal vacuolar degeneration in the epidermal basal layer not associated with psoriasiform hyperplasia or pustules. A perivascular inflammatory infiltrate was also observed, more prominent in the superficial dermis, predominantly lymphocytic, and with the presence of histiocytes, occasional eosinophils, and very rare plasma cells ( Fig. 2a). Likewise, periadnexal and perivascular epithelioid granulomas were identified (Fig. 2b,c). Stains for fungi and mycobacteria were negative. A subsequent complete blood count, electrolytes, and liver enzymes were within normal limits. Laboratory testing for human immunodeficiency virus (HIV) was negative. Rapid plasma reagin (RPR) titer was 1:64, and Treponema pallidum enzyme immunoassay (TP-EIA) test results were positive. With immunohistochemical staining for Treponema, scant (a) (b) (c) (d) Figure 2 (a) Focal vacuolar degeneration in the epidermal basal layer and perivascular inflammatory infiltrate, more prominent in the superficial dermis, predominantly lymphocytic, and with the presence of histiocytes, occasional eosinophils, and very rare plasma cells (Hematoxylin-eosin stain, original magnification 94). (b,c) Skin biopsy demonstrating periadnexal and perivascular epithelioid granulomas. (b) (Hematoxylin-eosin stain, original magnification 910), (c) (Hematoxylin-eosin stain, original magnification 940), (d) Immunohistochemical staining for Treponema show isolated spirochetes within the epidermis (black arrows, original magnification 940) (a) (b) Figure 1 (a,b) Multiple red-brown papules and ulcers on the trunk ª
