Although secondary pseudohypoaldosteronism (PHA) is rare in UTI, it is a known association. Features include hyponatremia and concomitant hyperkalemia.

The goal of a new article published in Frontiers in Pediatrics was to highlight these uncommon sequelae in UTI to avoid incorrect diagnosis and unnecessary investigations.

This study used clinical data of patients admitted and referred to a pediatric nephrologist at the University Malaya Medical Center from 2019-2020.

Three infants had hyponatremia and hyperkalemia during UTI episodes. Two of these were known to have posterior urethral valve (PUV) before the onset of UTI and one had UTI, which led to investigations confirming the diagnosis of bladder vaginal fistula. It was noted that the electrolyte derangements were temporary and resolved within 48-72 hours of treatment with i.v. fluid and appropriate antibiotic therapy. PHA was confirmed in only one. Reduced aldosterone activity could be due to absolute reduction in aldosterone titer or lack of aldosterone responsiveness at tissue level. In cases with reduced responsiveness, aldosterone titer is elevated. The infant who had PHA had the mentioned electrolyte abnormalities with a markedly elevated aldosterone titer. This signified defective action of the hormone at the level of mineralocorticoid receptor. Although the remaining two infants had no confirmatory hormonal study, all of them recovered within 48 hours of hospital admission, after receiving appropriate treatment for UTI. Moreover, there was a slower recovery of hyponatremia in relation to hyperkalemia, but none of these infants required salt replacement upon discharge.

It was recommended that infants with severe UTI and deranged electrolytes should be screened for structural abnormality and vice versa. Infants who require prolonged salt replacement or show involvement of other systems may require further evaluation, such as hormonal screening.

Source: Frontiers in Pediatrics. 2021; 9: 655010. Published online 2021 May5. doi: 10.3389/fped.2021.655010