Pseudohypoaldosteronism due to sweat gland dysfunction.
Pseudohypoaldosteronism is an uncommon disorder characterized by urinary sodium wasting and is attributed to a defect in distal renal tubular sodium handling with failure to respond to endogenous aldosterone. Sweat electrolyte values in other reported patients, when measured, have been normal. A 3.5-year-old girl developed repeated episodes of dehydration, hyponatremia, and hyperkalemia during the first 19 months of life. Serum sodium was as low as 113 mEq/liter and potassium as high as 11.1 mEq/liter. Her plasma and urinary aldosterone levels were persistently elevated (Figs. 1-4). Unlike patients with classic pseudohypoaldosteronism she demonstrated no urinary sodium wasting (Figs. 2 and 3). During episodes of hyponatremia and reduced sodium intake her urinary sodium was less than 5 mEq/liter. In addition, her sweat sodium concentration was consistently above 125 mEq/liter and salivary sodium concentration above 58 mEq/liter. Her chest x-ray, 72-hr fecal fat excretion, serum and urinary pancreatic amylase (amy-2) were normal, providing no evidence for cystic fibrosis. It is proposed that this patient represents a new variant of pseudohypoaldosteronism with excessive loss of sodium from the sweat and salivary glands instead of the kidneys.
D000450:Aldosterone / Q000378:metabolism*; D002675:Child, Preschool; D003681:Dehydration / Q000209:etiology; D005260:Female; D006801:Humans; D006947:Hyperkalemia / Q000209:etiology; D007010:Hyponatremia / Q000209:etiology; D007668:Kidney / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013542:Sweat / Q000032:analysis; D013543:Sweat Gland Diseases / Q000378:metabolism*
D000450:Aldosterone; D012964:Sodium; D011188:Potassium