Newborn 7 days old with vomiting and dehydration clinical examination was normal except for hyperpigmentation of nipple. Electrolytes Na: 120 meq. K: 9 meq. most likely diagnosis -: (A) Cong, adrenal hyperplasia, (B) Primary hypothyroidism, (C) Panhypopituitarism, (D) Pyloric stenosis
Answer is A. Congenital adrenal hyperplasia due to a defect in CYP21A2 is suggested by episodes of acute adrenal insufficiency with hyponatremia, hyperkalemia, dehydration & vomiting