Subacute combined degeneration: a case of pernicious anaemia without haematological manifestations.

Vitamin B12 deficiency can be caused by a diverse group of aetiologies. One of the less common of these is an autoimmune condition pernicious anaemia, so named after the most common physiological manifestation of B12 deficiency: anaemia. However, B12 is also necessary for nervous system function and its depletion can lead to dysfunction of the posterior columns of the spinal cord resulting in subacute combined degeneration (SCD). This disease, while debilitating in its acute phase, can usually be mostly if not fully reversed if caught early and treated appropriately. Early detection can prove challenging if there are no haematological manifestations of B12 deficiency and the only guidance is the high index of suspicion. We present a case of pernicious anaemia leading to SCD without any clinical or laboratory findings of anaemia in this report. © BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.