Ulceronecrotic Plaques, Patchy Scalp Alopecia and Visual Disturbance in a 46‐Year‐Old Man

A 46-year-old incarcerated man with chronic hepatitis C infection and intravenous drug use presented with a rapidly progressive pruritic eruption involving the scalp, trunk, and limbs, accompanied by patchy scalp alopecia and bilateral panuveitis. Examination demonstrated widespread erythematous papules and plaques with central necrosis, prominent scalp involvement, patchy alopecia, and palmoplantar hyperkeratosis. Skin biopsy revealed epidermal ulceration with dense dermal lymphohistiocytic infiltrate, while immunohistochemistry demonstrated numerous spirochetes and serology revealed a markedly elevated non-treponemal titre. This case of malignant syphilis (lues maligna) highlights the importance of clinicopathological correlation and consideration of syphilis in the differential diagnosis of ulceronecrotic dermatoses with systemic features.