Acquired, bilateral nevus of Ota-like macules.

Blue-brown macules of the face occurring on both sides of the forehead, temple, eyelids, malar area, alae of the nose, and root of the nose are often observed in middle-aged Japanese women. These lesions histologically are a form of dermal melanocytosis as shown by electron microscopic examination. They differ clinically from nevus of Ota. The differential diagnosis includes nevus of Ota, Riehl's melanosis (female facial melanosis), and melasma. The differences between them are discussed.