Acral Hyperpigmentation Due to Vitamin B12 Deficiency

Clinico-histopathological profile of acral hyperpigmentation in skin of colour- A case series and review of literature

“…Vitamin B12 (cobalamin) is a water soluble B complex vitamin. 8 It is obtained through dietary sources such as eggs, milk, beef, liver and organ meats. It is a critical coenzyme involved in DNA, proteins, lipid and carbohydrate metabolism.…”

“…It is a critical coenzyme involved in DNA, proteins, lipid and carbohydrate metabolism. 8 Deficiency may arise due to intrinsic factor deficiency, achlorhydria, ileac disease, malnutrition, malabsorption syndromes, or a strict vegetarian diet. 9 The patients present with anemia, neurological manifestations such as loss of vibration, proprioception, spasticity, paraplegia, urinary incontinence, mucocutaneous features such as glossitis, angular cheilitis, localised or diffuse hair depigmentation and cutaneous hyperpigmentation of face, nails, acral pigmentation involving hands and feet, palmar creases and flexural surfaces.…”

“…9 The patients present with anemia, neurological manifestations such as loss of vibration, proprioception, spasticity, paraplegia, urinary incontinence, mucocutaneous features such as glossitis, angular cheilitis, localised or diffuse hair depigmentation and cutaneous hyperpigmentation of face, nails, acral pigmentation involving hands and feet, palmar creases and flexural surfaces. 8,10 The pathogenesis of cutaneous hyperpigmentation due to vitamin B12 deficiency is poorly understood. Decreased vitamin B12 causes decrease in glutathione levels which leads to decrease in inhibitory effect on tyrosinase enzyme, thus leading to increased melanogenesis.…”

“…10 Vitamin B12 deficiency also causes defective melanin transfer from melanocytes to adjacent keratinocytes. 8 Blood tests reveal macrocytic anemia, hyper-segmented neutrophils and reduced serum vitamin B12. 9 Histopathology shows hyperkeratosis, increased melanin granules in the basal layer, scattered melanophages, and perivascular lymphocytic infiltrates in the upper dermis.Histopathology shows hyperkeratosis, increased number in melanin granules of the basal layer, scattered melanophages along with perivascular lymphocytic infiltrates in upper dermis.…”

Cyclosporine‐induced acrofacial hyperpigmentation: report of a rare occurrence and review of the literature

“…Cyclosporine is rarely considered in the differential diagnosis of acrofacial pigmentation. Relevant investigations would help differentiate it from common conditions with similar presentation like vitamin B12 deficiency, Addison’s disease, Cushing’s disease, hypo‐ or hyperthyroidism, and drug‐induced (tetracycline, antimalarials, clofazimine, zidovudine, antipsychotics, amiodarone, chemotherapeutics, oral contraceptives, amitriptyline, PUVA, and heavy metal) reaction 8,9 …”