[Secondary pseudohypoaldosteronism in neonates due to pyelonephritis and congenital urinary tract malformations].

We report two cases of neonates with secondary pseudohypoaldosteronism due to pyelonephritis and congenital urinary tract malformations. Both patients presented with failure to thrive, dehydration, severe hyponatraemia and metabolic acidosis. One of the patients also developed severe hyperkalaemia. Secondary pseudohypoaldosteronism may resemble congenital adrenal hyperplasia. Early diagnosis is essential since both conditions, when untreated, are fatal, and treatment of the two differs significantly. Differential diagnosis may be achieved by acute analysis of urine culture and renal ultrasonography.