pediatrics
Congenital Adrenal Hyperplasia Caused by 21 Hydroxylase Deficiency
Treatment
Corticosteroid replacement Mineralocorticoid replacement (salt-wasting form) Possibly reconstructive surgery Adrenal crisisin infants may result in hypotension and shock, accompanied by hyponatremia and hyperkalemia. Depending on age, it may manifest with lethargy, fatigue, vomiting, confusion, or even coma. Urgent therapy with IV fluids is needed. Stress doses ofhydrocortisone(100 mg/m2/day) are given by continuous IV infusion to prevent adrenal crisis if the salt-wasting form is suspected; the dose is reduced over several weeks to a more physiologic replacement dose. Maintenance treatment ofclassic 21-hydroxylase deficiencyis corticosteroids as replacement for deficient steroids (typically, a tablet form of oralhydrocortisone3.5 to 5 mg/m23 times a day, with total daily dose typically ≤ 20 mg/m2). For infants and younger children, tablets are crushed or split and mixed with liquid. Low-dosehydrocortisonegranules (sprinkles) are now available for the treatment of infants with congenital adrenal hyperplasia and may improve the accuracy of dosing. Hydrocortisoneis preferred in growing children because it is less potent than other corticosteroid preparations and causes less growth suppression. Postpubertal adolescents and adults may be treated withprednisone5 to 7.5 mg orally once a day or 2.5 to 3.75 mg 2 times a day,prednisolone4 to 6 mg orally once a day or 2 to 3 mg 2 times a day, ordexamethasone0.25 to 0.5 mg once a day or 0.125 to 0.25 mg 2 times a day. 12 months every 3 to 4 months. Overtreatment with a corticosteroid results in iatrogenic Cushing Syndrome , causing obesity, subnormal growth, and delayed skeletal maturation. Undertreatment results in inability to suppress ACTH with consequent hyperandrogenism, causing virilization and supranormal growth velocity in children and, eventually, premature termination of growth and short stature. Monitoring involves measuring serum 17- For thesalt-wasting form,in addition to corticosteroids, maintenance treatment includes mineralocorticoid replacement for restoration of sodium and potassium homeostasis. Oralfludrocortisone(usually 0.1 mg once a day, range 0.05 to 0.3 mg) is given if salt loss occurs. Infants often require supplemental oral salt for about 1 year. Close monitoring during therapy is critical. With illness, corticosteroid dosages are increased (typically doubled or tripled) to prevent adrenal crisis. Mineralocorticoid replacement is not adjusted. When oral therapy is unreliable (eg, severe vomiting or life-threatening situations), a single IM injection ofhydrocortisone(50 to 100 mg/m2) can be given. When the injection is given, children typically need to be evaluated in the emergency department to determine whether they require IV fluids, additional corticosteroids, or both. Affected female infants may require surgical reconstruction with reduction clitoroplasty and construction of a vaginal opening. Often, further surgery is required during adulthood. With appropriate care and attention to psychosexual issues, normal sexual function and fertility may be expected. Forprenatal treatment,a corticosteroid (usuallydexamethasone) is given to the mother to suppress fetal pituitary secretion of ACTH and thus reduce or prevent masculinization of affected female fetuses. Treatment, which is experimental, must begin in the first several weeks of gestation. Treatment ofnonclassic 21-hydroxylase deficiencydepends on symptoms. If asymptomatic, no treatment is required. If symptomatic, corticosteroid treatment is similar to classic 21-hydroxylase deficiency, but lower doses are often effective. Mineralocorticoid replacement is not needed. 