An Interesting case of hypokalemic paralysis

A 40-yr-old woman presented with complaints of weakness of both upper and lower limbs lasting for two days. She was found to have hypokalaemic periodic paralysis. She had thyroid goitre on examination and was a known hyperthyroid on treatment. However, on investigating it was found that she also had urinary potassium loss with metabolic acidosis and a reduced ability to acidify urine. The coexistence of distal renal tubular acidosis (RTA) was confirmed. There was no evidence of xerostomia or xerophthalmia, although rheumatoid factor and anti nuclear antibody were positive. The purpose of presenting this case is to show that in view of the strong male predominance of thyrotoxic periodic paralysis (TPP), female patients should be thoroughly investigated for possible additional precipitating factors, particularly when there are atypical metabolic features.