Pigmentation in vitamin B12 deficiency masquerading Addison′s pigmentation: A rare presentation

Abstract

A 35-year-female presented with generalized weakness, weight loss, and progressive pigmentation was worked up for suspicion of Addisons disease. On examination hyper pigmentation was noted on both palmar and dorsal aspect of hands involving knuckles, creases, feet, tongue, oral mucosa and gluteal region. There was no evidence of hypocortisolemia as initially suspected, and literature search revealed a possibility of vitamin B12 deficiency. She had megaloblastic anemia with a low serum vitamin B12, mostly due to poor dietary intake. Her hyper pigmentation resolved with vitamin B12 supplementation. Skin biopsy showed increased pigmentation at stratum spinosum and basal-layer. The mechanism of hyper pigmentation in vitamin B12 deficiency was due to an increase in melanin synthesis.

Reversible ecchymosis and hyperpigmented lesions: A rare presentation of dietary Vitamin B12 deficiency

“…[23] A hypothesis explained hyperpigmentation in Vitamin B12 deficiency due to increase synthesis of melanin with increased melanosomes in the basal layer of skin by decreasing the level of reduced glutathione, which activates tyrosinase and thus leads to transfer to melanosomes; a defect is also described in the melanin transfer between melanocytes and keratinocytes, resulting in pigmentary incontinence. [45] The patients with nutritional Vitamin B12 deficiency also had bleeding manifestations and qualitative abnormalities of platelets, i.e., abnormal aggregation to adenosine diphosphate, collagen, epinephrine, and ristocetin. [6]…”

Melanoderma: uncommon presentation of a common condition

“…There are few reports hyperpigmentation with vitamin B12 deficiency in the literature 3 4. The likely explanations postulated for increased pigmentation in vitamin B12 deficiency include increased melanin synthesis and deposition in the basal layer of the epidermis rather than a defect in the melanin transport or melanocyte dysfunction 3–5…”

Hiperpigmentación cutánea secundaria a déficit de vitamina B12 en un lactante

“…3) Por último, Marks hace referencia a que habría un cambio en la distribución de la melanina y afirma que, en las anemias megaloblásticas, existiría un defecto en el transporte o incorporación de la melanina dentro de los queratinocitos, lo que ocasionaría, en los pacientes, incontinencia pigmentaria. 10,11 Ante la sospecha clínica de un paciente con deficiencia de vit. B12, la anamnesis debe incluir preguntas acerca de enfermedades digestivas, cirugías intestinales y hábitos dietarios, ya que podrían ser factores de riesgo para presentar la hipovitaminosis.…”