[Becker's melanosis: a case report].

Becker melanosis is a dermatosis characterized by hyperpigmentation and hypertrichosis in absence of cells nevus; its frequency is unknown an its presentation is rare in the infancy; appearance usually during puberty. In the last years its association to anomalies of development increase the importance of this entity. We present the case of 4 years old girl considered the youngest report in the literature, with affection of trunk and right leg associated to minimum shorten of right leg.