Bilateral hyperkeratosis of the nipples and areolae with linear nevus and acanthosis nigricans: A rare case report.

Hyperkeratosis of the nipples and areolae (HNA) is an uncommon skin disorder with no definite aetiology. We report a case of a 16-year-old boy, who presented with bilateral pigmentation and thickening of the nipples and areolae, accompanied with linear brown protrusions on the anterior neck and a velvet like appearance with pigmentation on the axillary bilaterlly. Based on clinical and histopathological, and dermatoscopic findings, the diagnosis of bilateral HNA accompanied by linear nevus and acanthosis nigricans was made. The skin lesions were improved by treatment with topical calcipotriol gel.