Addisonian pigmentation secondary to vitamin B12 deficiency.

A 32 yr old male† presented to the department of Dermatology, All India Institute of Medical Sciences, Bhopal, in March 2019, with progressive darkening of his face for the last six months. He was a strict vegetarian and had no other systemic complaint, except occasional malaise and easy fatigability. There was diffuse dark-brown pigmentation over face (Fig. 1A) and dorsum of hands (Fig. 1B), exaggerated over knuckles. Discrete brown macules were noted over bilateral palm (Fig. 1C) and buccal mucosa (Fig. 1D). On routine investigation, he had macrocytic anaemia [Hb 7.1 g/dl (normal 14-16.5 g/dl), PCV 20.3% (normal 40-54%) and MCV 80.88 fl (normal 80-96 fl)], leukopenia [TLC 2,800/cmm (normal 4000-11000/cmm)], thrombocytopenia [platelet 62,000/cmm (normal 1.5-4 lacs/cmm)] and hyperbilirubinemia [total bilirubin 6.3 ng/mg/dl (normal 0.2-1.2), direct 1.15 (normal 0.0-0.2) and indirect 5.16 (normal 0.0-0.7)]. Further evaluation revealed normal morning cortisol [11.01 µg/dl (normal 10-20)], low vitamin B12 [112.0 ng/ml (normal 200-900)] and normal folate level [19.96 ng/ml (normal 2-20)] and thyroid profile. A case of Addisonian pigmentation due to vitamin B12 deficiency was made, and he was treated with thrice weekly injections of vitamin B12 (1000 mg) and folic acid for two weeks followed by weekly injections for two months. The pigmentation improved significantly (Fig. 2) in six weeks along with normalization haematological parameters and liver function tests (Hb 13.4, bilirubin 1.42 and TLC 7590). We could not pinpoint the reason behind the deficiency in his case although nutritional deficiency of vitamin B12 is common in this region. He was encouraged for adequate intake of vitamin B12 through food including milk. He was referred to gastroenterology to rule out malabsorption and advised to continue injections every three months. Until last follow up at 10 months, there was no relapse of clinical signs and symptoms.Fig. 1: Diffuse dark-brown pigmentation over (A) face, more prominent over lips, forehead and nose, (B) dorsum of hands with more prominent darkening over the dorsal aspect of the joints (black arrow) (C) with discrete dark-brown pigmented macules over bilateral palm and palmer aspect of fingers (black arrow), and (D) similar discrete brown macules over dorsal surface of tongue (white arrow).Fig. 2: Improvement in pigmentation in all affected sites six weeks after treatment with vitamin B12 injections.Acknowledgment: Authors acknowledge Dr Soumya Narula, Junior Resident, department of Dermatology, All India Institute of Medical Sciences, Bhopal for help in management of the patient. Financial support & sponsorship: None. Conflicts of Interest: None.