4. What is Congenital Adrenal Hyperplasia (CAH)? Congenital Adrenal Hyperplasia (CAH) is a family of inherited disorders affecting the adrenal glands. Autosomal recessive (mutation of chromosome 6 21-hydroxylase enzyme impairment) Commoner in consanguineous marriage
10. Clinical Manifestation Cortisol deficiency – hypoglycemia, inability to withstand stress, vasomotor collapse, hyperpigmentation, apneic spells, muscle weakness & fatigue. Aldosterone deficiency – hyponatremia, hyperkalemia, vomiting, urinary sodium wasting, salt craving, acidosis, failure to thrive, volume depletion, hypotension, dehydration, shock, diarrhea. Androgen excess – ambiguous genitalia, virilization of external genitalia , hirsutism, early appearance of pubic hair, penile enlargement , excessive height gain and skeletal advance. *Late onset CAH – normal genitalia, have acne, hirsutism, irregular menses/amenorrhea.
11. Investigation Karyotyping (determine sex chromosome) Abdominal Ultrasound – to detect presence of uterus, cervix and vagina. Serum 17-hydroxyprogesterone
12. Diagnosis Biochemical diagnostic studies: - elevated serum 17-OHP (0.25mg IV bolus of ACTH after 60min) 100,000 10,000 ACTH stimulated 1,000 100 0 10,000 100 1,000 100,000 Basal 17-OHP, ng/dL
13. Management Glucocorticoids (oral hydrocortisone etc.) 13-18 mg/m²/24hr in 3 divided doses. Monitoring: serum concentration of adrenal precursors (17-OHP) & linear growth and skeletal age assessment. *During stressful state ie febrile ilnesses or surgery, 3x higher dose. *In severe emergency: intramuscular SC glucocorticoid (Solu-Cortef) Mineralocorticoid therapy (fludrocortisone) at a dose of 0.1-0.2 mg/24hr + sodium chloride supplement 1-2g daily. Monitoring: serum sodium & potassium, plasma renin activity levels. Surgical correction of ambiguous genitalia by 1-2 y/o normal development of gender identity.
14. CYP21 genotyping can be performed in a family with history of CAH. Treatment with dexamethasone to suppress fetal ACTH-induced androgen production can reduce/eliminate ambiguity of external genitalia in affected female fetuses.
16. Adrenal Crisis important to recognize because of its potentially life-threatening implications when the adrenal is prevented from producing normal amounts of its vital hormones Symptoms and signs of adrenal crisis are varied and nonspecific. In infancy these include lethargy, vomiting, poor appetite and failure to thrive. In older children chronic fatigue, headache, gastrointestinal symptoms, salt-craving and excess skin pigmentation may be noted. the underlying problems include low blood sugar, low blood sodium, dehydration, low blood pressure, all predisposing the individual to heart failure and shock (collapse).
17. References Nelson Essentials of Paediatrics, 5th ed, 2006, Elsevier Inc. Illustrated Textbook of Paediatrics, 3rded, Tom Lissauer, Graham Clayden, 2007,Elsevier Limited. Pediatrics Endocrinology, Mechanisms, Manifestations and Management, Ora H. Pescovitz, Erica A. Eugster, 2004 by Lippincott Williams & Wilkins. http://www.caresfoundation.org/ http://www.aafp.org/