A painful periumbilical rash.

Jacquet's erosive dermatitis, or dermatitis syphiloides posterosiva, is classified as a severe irritant dermatitis characterized by erythematous papules and nodules with erosive, punched-out lesions. It can be found in the perineal distribution and is frequently reported in infants over 6 months of age. In adults, it is associated with urinary or fecal incontinence. We present a case of a 21-year-old white woman with a history of chronic umbilical drainage and a 3-year history of a periumbilical rash with red, friable, well-demarcated papules. Biopsy revealed pseudoepitheliomatous hyperplasia with focal epidermal erosion and a superficial perivascular infiltrate of lymphocytes and plasma cells. Our case sheds light on this uncommon diagnosis in an unlikely location.