[A case of alcoholism presenting pellagra and hypokalemic myopathy]

A 32-year-old man with chronic alcoholism over 10 years developed skin eruptions, dark-red tongue and severe watery diarrhea, followed by weakness of bilateral lower extremities. Physical examination revealed hyperpigmented skin eruptions with scales on the dorsa of his hands and extensor aspects of his forearms. Neurological examination showed proximal muscle weakness of both lower extremities, hyperactive knee and ankle jerks, positive Chaddock reflexes and stocking type sensory disturbances. Laboratory data revealed elevation of myolytic enzyme, hypokalemia and decrease of niacin level in the blood. Diagnosis of hypokalemic myopathy and pellagra was made. With the correction of serum potassium level, muscle weakness improved rapidly and with the supplement of niacin, other physical signs and symptoms improved. In this case hypokalemic myopathy could be attributed to the alcoholic malnutritional state such as pellagrous diarrhea, malnutrition, malabsorption and others.