Idiopathic disseminated comedones in a child.

An 11-year-old girl had an uncountable number of hyperkeratotic comedo-like lesions on her shoulders, arms, buttocks, and thighs, present for 5 years. Depressed scars, cysts, and small purulent nodules were observed in involved areas. Her 6-year-old brother does not have similar lesions. Other members of her family were not available for examination. Light microscopy showed dilated elongated infundibula filled with corneocytes and arranged in a lamellated pattern. A peri-infundibular inflammatory infiltrate was present.