Synopsis
Understand the enzyme defect and salt-wasting risk, maintain life-saving cortisol replacement without chronic excess, and coordinate growth, puberty, fertility, genetics and crisis prevention across specialist care.
- Congenital adrenal hyperplasia is a group of inherited steroid-synthesis disorders; 21-hydroxylase deficiency causes most cases and produces cortisol deficiency with excess adrenal androgen, plus aldosterone deficiency in salt-wasting disease.
- Classic salt-wasting CAH can present in infancy with vomiting, weight loss, dehydration, hyponatraemia, hyperkalaemia and shock; newborn screening and genital appearance do not identify every affected child.
- Treatment replaces glucocorticoid and, when deficient, mineralocorticoid while restraining excess ACTH and androgen; complete biochemical suppression at the cost of iatrogenic Cushing syndrome is not the goal.
Key red flags
Vomiting, diarrhoea, hypotension, confusion, hypoglycaemia or collapse in steroid-dependent CAH is adrenal crisis until assessed and needs immediate emergency hydrocortisone.
Investigation priorities
Identify the characteristic precursor elevation and follow biochemical control in 21-hydroxylase deficiency.
Management branches
A steroid-dependent person is haemodynamically unwell, hypoglycaemic or unable to absorb oral replacement.
- Give intramuscular or intravenous hydrocortisone immediately; obtaining cortisol or ACTH must never delay treatment.
- Call emergency services, establish monitoring and restore circulation with 0.9% sodium chloride while checking glucose and electrolytes.
Classic CAH is established and the patient is clinically stable on oral therapy.
Key medicines
Immediate-release hydrocortisoneNICE recommends 15 to 25 mg orally each day in two to four divided doses, using higher CAH dosing only with specialist advice.
FludrocortisoneUse the specialist-selected daily dose, commonly initiated within the NICE 50 to 300 microgram range and adjusted to clinical and renin response.