Oestrogen associated with ultraviolet B irradiation recapitulates the specific melanosome distribution observed in caucasoid melasma

Melasma is characterized by light to dark brown macules that usually occur on the face. Melasma occurs in 10-15% of pregnant women and in 10-25% of women taking oral contraceptives. Fertile women are most likely to develop melasma. Histological examination of melasma lesional skin revealed mainly pigmentary disorders with an increased melanin deposition in all layers of the epidermis including the horny layer and a frequent presence of melanophages in the dermis. On the other hand in the upper dermis, a disruption of the basement membrane in 3.9% of cases, an abundance of elastotic material and an increased number of blood vessels and mast cells have been reported in melasma. This article is protected by copyright. All rights reserved.