A Case of Secondary Pseudohypoaldosteronism in a Neonate not Due to Urinary Tract Issues.

Abstract

In this report, we present a case of a female infant diagnosed with secondary PHA who exhibited weight loss, hyponatremia, hyperkalemia, and metabolic acidosis without the presence of UTA or UTI. The patient was a female infant born at 35 weeks gestation who developed electrolyte abnormalities and was diagnosed with secondary pseudohypoaldosteronism (PHA). Initially managed for transient tachypnea of the newborn, she developed respiratory distress requiring mechanical ventilation. Subsequently, she exhibited persistent hyponatremia, hyperkalemia, and metabolic acidosis despite adequate fluid therapy, prompting consideration of adrenal insufficiency and congenital adrenal hyperplasia (CAH). Treatment with hydrocortisone and fludrocortisone was initiated empirically until hormonal analyses excluded CAH. Further evaluation excluded urinary tract anomalies and infections as underlying causes, implicating secondary PHA. The infant responded well to saline and electrolyte replacement therapy, with normalization of electrolyte levels and clinical improvement. Follow-up assessments demonstrated resolution of electrolyte imbalances, and the patient was discharged after 27 days without further complications. Secondary PHA, characterized by renal tubular resistance to aldosterone, typically presents with severe electrolyte disturbances in infancy. It can occur independently of urinary tract abnormalities or infections, highlighting the importance of considering this diagnosis in neonates and infants presenting with hyponatremia, hyperkalemia, and metabolic acidosis that do not respond to conventional therapies. Early recognition and appropriate management, including fluid-electrolyte correction and hormone replacement if indicated, are crucial to prevent life-threatening complications associated with salt-wasting syndromes in this vulnerable population.