Case Report: A 5-month-old girl born to first-cousin parents was referred to endocrinology for evaluation following two hospitalizations for vomiting and dehydration with severe hyponatremia and hyperkalemia. She had a history of recurrent emesis and poor weight gain, with a reportedly normal abdominal and renal ultrasound.
Initial evaluation showed hyponatremia with elevated renin 170 ng/ml/hr (normal 2-37 ng/ml/hr) and aldosterone 275 ng/dl (normal 5-90 ng/dl). The suspected diagnosis was pseudohypoaldosteronism type 1 (PHA). Treatment was initiated with sodium supplementation and she subsequently maintained normal sodium and potassium levels with relative improvement in weight gain and less frequent emesis.
Three months' later, she re-presented with severe bilious emesis. Abdominal X-ray indicated obstruction. Urgent ultrasound showed grossly distended, fluid-filled hyper peristaltic stomach and duodenum, indicating obstruction distal to the third part of the duodenum. An upper-GI fluoroscopic study revealed distention of the duodenal bulb and descending loop. The third part of the duodenum showed funnel-shaped narrowing and obstruction to the flow of contrast. These findings suggested a duodenal web or duodenal stenosis/partial atresia. At laparotomy, a duodenal web was found and the patient underwent duodenojejunostomy.
Following surgical correction, the patient had complete resolution of emesis with normalization of the electrolytes, renin and aldosterone. She no longer required sodium supplementation. Genetic testing for PHA was negative.
Conclusion: This rare case highlights the presentation of transient PHA secondary to intestinal obstruction. Only one similar case has been previously described in an infant¹. Urinary tract infection or obstruction are the most commonly found causes of secondary transient PHA in infancy. In the scenario we describe, PHA is due to gastrointestinal losses of sodium and water resulting in decreased renal perfusion from dehydration and consequent rise in renin and aldosterone. This gives the biochemical picture of PHA.
¹ Nissen M, Dettmer P, Thränhardt R, Winter K, Niemeyer T, Tröbs RB. Congenital Jejunal Membrane Causing Transient Pseudohypoaldosteronism and Hypoprothrombinemia in a 7-Week-Old Infant. Klin Padiatr. 2017 Sep;229(5):302-303.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology