Rare case of pseudohypoaldosteronism in a neonate secondary to congenital hydrometrocolpos.

Pseudohypoaldosteronism (PHA) due to obstructive uropathy, urinary tract infections and congenital urogenital malformations has been reported in the literature; however, there are no reports of PHA associated with hydrometrocolpos due to a common urogenital tract. Hydrometrocolpos is a condition resulting in distension of the vagina and uterus due to accumulation of secretions (other than blood), caused by increased oestrogenic stimulation and vaginal outflow obstruction. We report on a neonatal case of PHA caused by recurrent hydrometrocolpos presenting with vomiting and poor weight gain. There was significant hyponatraemia, hyperkalaemia, and anaemia requiring medical stabilisation prior to surgery. The mechanism by which PHA occurs in obstruction involves renal tubular dysfunction due to pressure from hydronephrosis and the release of intrarenal cytokines. In addition, there is an immature or resistant renal tubular responsiveness to aldosterone during infancy. Clinicians should be aware of this uncommon but serious presentation. © BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.