Transient pseudohypoaldosteronism type I in infants with urinary tract infections and/or uropathy: insights from a French multicenter cohort.

backgroundDuring the first year of life, and especially in the first 6 months, urinary tract infections, congenital anomalies of the kidney and urinary tract (CAKUT)-particularly obstructive types-and the coexistence of both factors may lead to transient resistance to aldosterone. This condition is characterized by fluid and salt loss despite significant activation of the renin-angiotensin-aldosterone system, and by electrolyte disturbance featuring hyponatremia, hyperkalemia, and metabolic acidosis with a normal anion gap. Transient resistance to aldosterone is not widely recognized by clinicians. Our objective was to describe the clinical presentations and management strategies in order to propose a comprehensive diagnostic approach.

methodsWe conducted a 13-year retrospective study involving 35 children from eight centers across France, as well as one child from Switzerland.

resultsMost of the children in our cohort were under 6 months of age (68.6% male). The clinical presentation of pseudohypoaldosteronism was variable and often similar to that of adrenal insufficiency. The pyelonephritis diagnosis was retained in 94.3% of the cases and uropathy was present in 85.7% of the children. Treatment was primarily symptomatic, and included intravenous hydration, salt supplementation, correction of potassium levels, and antibiotic therapy when pyelonephritis was diagnosed.

conclusionTransient type I pseudohypoaldosteronism should be promptly considered in any infant presenting with a deteriorating general condition and fluid and electrolyte imbalances, particularly hyponatremia and hyperkalemia, in the context of acute pyelonephritis and/or uropathy. WHAT IS KNOWN: • Transient type I pseudohypoaldosteronism affects infants under 1 year of age with congenital anomalies of the kidney and urinary tract during acute pyelonephritis. • Treatment mostly consists of antibiotics and parenteral fluids. WHAT IS NEW: • This is the first article to report on 34 cases from a single country. • The importance of renal ultrasound in the context of urinary tract infection with salt wasting symptoms in infants without known congenital anomalies the kidney and urinary tract. • The importance of assessing hydro-electrolytic status in cases of urinary tract infection in infants under 6 months with or without known congenital anomalies of the kidney and urinary tract. • A decision tree for the diagnostic approach of transient type I pseudohypoaldosteronism.