Disorders of pigmentation

Skin colour is due to a mixture of the pigments melanin, oxyhaemoglobin (in blood), and carotene (in the stratum corneum and subcutaneous fat). Pigmentary diseases are common and particularly distressing to those with darker skin. Disorders of pigmentation often involve melanocytes. Vitiligo is the commonest disease of reduced pigmentation, and melasma is the commonest of hyperpigmentation.