Congenital adrenal hyperplasia: issues in diagnosis and treatment in children

Congenital adrenal hyperplasia (CAH) is a common disorder of impaired adrenal cortisol biosynthesis with associated androgen excess. The clinical presentation of 21-hydroxylase deficiency, the commonest cause of CAH, forms a spectrum and can be divided into classic and non-classic types. The former consists of life threatening salt wasting and non-life threatening simple virilizing phenotypes. Patients with the non-classic form are asymptomatic or have mild features of androgen excess. Most developed countries have newborn screening facilities for CAH. In the absence of newborn screening, the diagnosis of CAH may be missed or delayed. This can result in neonatal mortality in salt wasting forms and incorrect sex of rearing in females with simple virilizing form. The diagnosis is reached by demonstrating high serum 17-hydroxyprogesterone (17OHP) levels. Preterm birth and neonatal illness can cause physiological elevation of 17OHP, thus complicating the diagnosis of CAH in the newborn period. Prenatal diagnosis and treatment with dexamethasone to prevent virilization of affected female fetuses is another area of controversy. The management of CAH is complicated by the need to use supraphysiologic doses of glucocorticoids to suppress adrenal androgen synthesis. In this review, the authors address pertinent issues related to the diagnosis and management of CAH in children.