Thyrotoxic periodic paralysis in a hispanic man.

Thyrotoxic periodic paralysis occurs much more frequently in Orientals than in whites, and has rarely been reported in patients of Hispanic descent. A 28-year-old Mexican man presented with acute onset of bilateral lower extremity weakness after ingestion of a large carbohydrate meal. Laboratory investigation revealed severe hypokalemia, with a serum potassium level of 2.1 mmol/L (2.1 mEq/L), and hyperthyroidism. Administration of potassium chloride resulted in normalization of the serum potassium level and resolution of muscle weakness. Treatment with propranolol, and subsequent restoration of a euthyroid state with iodine 131, was effective in preventing further episodes of paralysis. Thyrotoxic periodic paralysis, although rare, may occur in Hispanic patients, and should be considered in the differential diagnosis of muscle weakness in this population.