Skin pigmentation in a patient with vitamin B12 deficiency presented with subacute combined degeneration of spinal cord

Vitamin B12 deficiency results in multisystem manifestations. A 30-years-old man presented with progressive weakness of lower limbs along with numbness. Patient had pale colour and noticed progressive pigmentation over dorsal and palmar aspects of both the hands and the feet. Neurological examination revealed absent ankle jerks, sensory impairment until T5 level, loss of joint position sensation and positive Romberg's sign. Workup showed macrocytic anaemia and hypersegmented neutrophils. There was no evidence of hypocortisolism. Magnetic Resonance Imaging of brain and spine was normal; however, Electromyography/Nerve conduction studies were suggestive of demyelinating neuropathy. His clinical and lab findings were suspicious of B12 deficiency, which was found to be very low. Hyperpigmentation is rare in B12 deficiency as presenting symptoms and diagnosis may be overlooked. Therefore, vitamin B12 levels should be checked as any delay in diagnosis and treatment will result in progression of Subacute Combined Degeneration of the spinal cord to the extent that it becomes irreversible.