Background: Pseudohypoaldosteronism (PHA) is a rare entity inducing, in case of late or missed diagnosis, life-threatening clinical and biochemical complications.
Objective and hypotheses: To report a case of 4-week-old boy with failure to thrive, dehydration, hyponatremia, hyperkalemia, metabolic acidosis. The first diagnosis was congenital adrenal hyperplasia, but in the evolution, the right diagnosis of PHA was retained.
Method: The baby presented to a general hospital with failure to thrive (actual weight below the weight at birth), clinical sign of dehydration (no vomiting or diarrhoea), dyselectrolytemia (hyponatremia, hyperkalemia) and metabolic acidosis. The first diagnosis was adrenal crisis and intravenous hydrocortisone was started. 24 h later, he was transferred to our Department, with a better clinical appearance, but with persisting hyponatremia and hyperkalemia. He is the second child of non-consanguineous parents. No history of sudden infant death, but a paternal cousin had transient problems with salt in the neonatal period.
Results: An extensive hormonal profile revealed normal 17 hydroxyprogesterone level, high cortisol, renin and aldosterone levels, high urinary sodium and low potassium, confirming biologically the clinical suspicion of PHA. The sweat test was normal. Neither urinary tract obstruction, no infection. As the clinical evolution, response to hydrocortisone and biological results were suggestive of PHA, hydrocortisone was stopped and normal salt was added into the milk. The clinical and biological course was satisfactory (weigh gain of 50 g/d, stabilized sodium and normal potassium levels).
Conclusion: Considering the clinical spectrum, family history, favourable response to sodium supplementation and kidney restricted aldosterone resistance (no sodium loss through sweat) we assume that this PHA is a renal type 1. A genetic analysis is under way. Our goal in describing this case is to underline the necessity to have in mind a differential diagnosis for clinical and biological appearance of CAH, notably early in the presentation, when the hormonal profile is not completely available.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology