Knuckle Hyperpigmentation and Melasma Associated with Vitamin B12 Deficiency: A Case Report

Abstract

Cyanocobalamin is essential in humans for the methylation process which is important for deoxyribonucleic acid and cellular metabolism. In its deficiency, haematological, neurological, and even dermatological manifestations arise. We report a case of a young female patient who presented with hyperpigmentation of the dorsal aspects of knuckles along with melasma attributed to a deficiency of vitamin B12. The cellular maturation is incomplete in vitamin B12 insufficiency which leads to cytopenias and tyrosinase activity is enhanced which results in hyperpigmentation of skin. Disturbance in the pattern of skin pigmentation can be an early sign of vitamin B12 deficiency which appears before anaemia. Dermatological signs if identified early, anaemia and severe neurological complications can be prevented and treated.