Infants with undetected CAH may present to the emergency department at 7–14 days with which sign?

• A. Hypernatremia
• B. Congestive heart failure
• C. Jaundice
• D. Shock

Answer: (D)

Infants with undetected CAH have aldosterone deficiency leading to renal salt wasting. This causes loss of sodium and water, producing dehydration and reduced circulating blood volume. As this hypovolemia progresses in the first couple of weeks of life, perfusion to tissues drops and shock develops. So, the sign you’d expect in a salt-wasting crisis around 7–14 days is shock from hypovolemia. Hypernatremia isn’t typical because the problem is sodium loss with hyponatremia rather than high sodium; congestive heart failure and jaundice don’t specifically reflect the acute hypovolemic state seen in this crisis.