Salt losing nephropathy simulating congenital adrenal hyperplasia in an infant.

Pseudo-hypoaldosteronism occurring predominately in male infants has been reported in association with a spectrum of urologic diseases including obstructive uropathy. This is thought to reflect tubule unresponsiveness to aldosterone. We report a case, which was misdiagnosed as a case of congenital adrenal hyperplasia and treated inappropriately with hydrocortisone and fludrocortisone for 12-months before he had a urinary tract infection and was discovered to have obstructive uropathy on ultrasound. He presented with vomiting, dehydration, hyperkalemia, hyponatremia and metabolic acidosis. His initial 17 hydroxyprogestrone was high. His electrolytes improved to normal after relieving the obstruction by vesicostomy and his treatment weaned slowly without complications. This case demonstrates the importance of urine culture and ultrasound examination in suspected cases of pseudo-hypoaldosteronism.