THU188 Clinical Conundrum: Salt Wasting Congenital Adrenal Hyperplasia With Paradoxical High Cortisol

Disclosure: C. Pillai: None. Background: Salt wasting congenital adrenal hyperplasia (CAH) is a severe life-threatening condition and thus a cannot miss diagnosis. In salt wasting CAH, cortisol is generally very low. An ACTH stimulation test is often used to diagnose adrenal insufficiency and initiate life-saving hydrocortisone therapy. Clinical Case: I present a case of a male infant who was found to have salt-wasting CAH crisis despite a paradoxically high serum cortisol. He had an abnormal newborn screen for CAH. He was sent to the ER for reportedly high 17-hydroxyprogesterone (17-OHP). Endocrine was consulted and a serum 17-OHP, ACTH and cortisol level was requested. He was an incredibly difficult patient to collect blood work and after multiple attempts only a serum cortisol was collected. He was admitted for an ACTH stimulation test to rule out salt wasting CAH. His physical exam was unremarkable with male external genitalia with descended prepubertal testes. His cortisol from the ER resulted at 36.5 mcg/dL without any steroid administration in the morning. Family refused to do any additional blood work in the morning. Even anesthesiology was not able to collect the requested labs. The ACTH stimulation test was canceled, and he was discharged with close follow-up in 1 week. The state newborn screen department called and reported his initial 17-OHP was undetectably high. He was seen the same day and his BMP showed clear signs of salt wasting. His serum sodium was 131 mmol/L and potassium was 7.2 mmol/L. He was admitted for a salt wasting crisis and responded well to hydrocortisone and fludrocortisone. Serum sodium and potassium normalized. Blood draw issues continued and only BMP were collected during the hospitalization. 17-OHP after several days of therapy was 3270 ng/dl. 17-OHP, sodium and potassium have normalized on therapy. Genetic testing is pending. Conclusions: By reporting this case, I draw attention to the possibility that high levels of cortisol do not definitely rule out salt-wasting CAH. Reference Ranges: NA 132 - 145 mmol/L K 3.0 - 6.0 mmol/L Cortisol: 1.7 - 14.0 ug/dL 17 OHP:INTERPRETIVE INFORMATION for 17-Hydroxyprogesterone in premature and normal male infants: Premature (26 to 28 weeks) 124 to 841 ng/dL Premature (29 to 35 weeks) 26 to 568 ng/dL Full term Day 3 7 to 77 ng/dL 4 days to 2 months Less than 200 ng/dL. Presentation: Thursday, June 15, 2023