A case report of pseudohypoaldosteronism type 1 initially misdiagnosed as congenital adrenal hyperplasia in a 3-month-old infant

Pseudohypoaldosteronism type 1 (PHA1) is a rare and serious disorder caused by aldosterone resistance, leading to significant disturbances in electrolyte balance. Due to overlapping clinical manifestations, it is frequently misidentified as congenital adrenal hyperplasia (CAH), resulting in unnecessary corticosteroid therapy. We reported on the case of a 3-month-old infant who had been initially diagnosed and treated for CAH due to severe salt-wasting symptoms. Further biochemical evaluation and genetic analysis later confirmed PHA1. The patient achieved clinical stabilization with fludrocortisone and sodium supplementation. This case underscored the necessity of differentiating PHA1 from CAH through repeated biochemical assessments and genetic testing to ensure an accurate diagnosis and appropriate treatment strategy.