Melasma.

Melasma is a common acquired hypermelanosis that primarily affects women of skin type IV-VI. It tends to appear on sun-exposed areas of face and neck. The exact pathogenesis is linked with many factors include ultraviolet radiation, pregnancy, hormonal activity, thyroid abnormalities, and medications. Melasma, which involves increased melanin production and melanocytosis, may be principally epidermal, dermal, or mixed. Mainstays of treatment include topical hypopigmenting agents, lasers, chemical peels, and dermabrasion.