Extensive inflammatory nevus comedonicus involving half of the body.

Nevus comedonicus is an uncommon variant of adnexal hamartoma without known cause. It usually occurs on the face, neck and chest and appears as groups of closely arranged dilated follicular openings with keratin plugs. We report extensive inflammatory nevus comedonicus in a 14-year-old boy involving half of his body, limited by the midline, with suppuration and residual scarring. The lesions first appeared at 3 years of age and worsened at the start of puberty. The clinical features, etiopathology, histopathology and treatment options of nevus comedonicus are briefly reviewed in the light of the literature.