Nondiabetic neuropathy in a patient with diabetes.

A case of peripheral neuropathy in a patient with diabetes who had atypical clinical findings is presented. Because of the atypical initial manifestations and short duration of insulin-dependent diabetes, another cause of the neuropathy was suspected. The presence of vitiligo, hypothyroidism, and diabetes prompted a search for evidence of pernicious anemia. Despite a normal blood cell count, the diagnosis of pernicious anemia was confirmed on the basis of an increased serum gastrin level and antiparietal cell antibody titer. Treatment with vitamin B12 resulted in an arrest, but not a reversal, of the signs of peripheral neuropathy. In patients with diabetes, vitamin B12 deficiency should be suspected; its early diagnosis and treatment are important in minimizing neurologic damage.