Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder caused by a defect in any of the five enzymatic steps required to synthesize cortisol from cholesterol. The deficiency of cortisol leads to adrenocortical hyperplasia and overproduction of intermediary metabolites. Depending on the enzymatic step that is deficient, there may be signs, symptoms, and laboratory findings of mineralocorticoid deficiency or excess, incomplete virilization or premature androgenization of the affected male; and virilization or sexual infantilism in the affected female.
All newborns in the United States are screened for classic CAH caused by genetic 21-hydroxylase deficiency during the first few days of life. This test does not identify nonclassic CAH.
Diagnosis of CAH includes:
The body needs more cortisol when it is under physical stress. Adults and children with classic CAH need close medical attention and may need to take more of their medication during these times. They may also need more medication if they:
People who have classic CAH need to wear a medical alert identification bracelet or necklace. To alert medical professionals in case of an emergency, the bracelet or necklace should read: "adrenal insufficiency, requires hydrocortisone." Adults or parents also need to learn how to give an injection of hydrocortisone if there is an emergency.
Patients with classic CAH need to take medication daily for their entire lives. If a patient stops taking his or her medication, symptoms will return.
The body makes different amounts of cortisol at different times in life, so sometimes a patient's dose of medication may be too high or too low. Taking too much medication to replace cortisol can cause symptoms of Cushing's syndrome. These include:
It is important to alert the health care provider if these symptoms appear so that he or she can adjust the medication dose.
Girls who are born with ambiguous external genitalia may need surgery. For example, surgery is necessary if changes to the genitals have affected urine flow.
Surgery for treatment of classic CAH should be done by an experienced surgeon who has expertise with this specific type of surgery. Parents may want to consider surgery for their child during infancy, or they may want to delay until later in childhood. Parents should work with their child's health care providers to determine the best timing of treatments.