Urinary tract malformation and infection with hyperkalemia and decreased fractional excretion of potassium in an infant.

We describe an uncircumcised male infant treated for urinary tract infection who exhibited multiple hormonal and electrolyte abnormalities consistent with a diagnosis of transient pseudohypoaldosteronism. Successful treatment of the urinary tract infection was accompanied by the resolution of all hormonal and electrolyte abnormalities, including hyperaldosteronemia, hyperreninemia, hyponatremia and hyperkalemia. Radiographic examination revealed marked left dilatation of the renal pelvis and hydroureter but no vesicoureteral reflux. Owing to the possibilities of future renal scarring, decreased renal function, and hypertension, evaluation of urinary tract malformation and appropriate hormonal studies should be performed in infants with urinary tract infection and hyperkalemia.