Reversible Facial Hyperpigmentation Associated With Vitamin B12 Deficiency.

Vitamin B12 (cobalamin) deficiency is common in developing countries. Its dermatologic manifestations include hair and nail changes and glossitis. Cases of generalized hyperpigmentation associated with vitamin B12 deficiency have rarely been reported. Localized hyperpigmentation is less frequently described, affecting palms, soles, and flexural areas. We report a rare case of reversible melasma-like cutaneous hyperpigmentation associated with pernicious anemia and discuss the possible mechanisms of this association.