We present the case of a Caucasian girl who in 1991 at the age of 4 started virilising and was diagnosed to have 21-hydroxylase deficiency. She started her periods at 10 and has been under regular follow up. In 2004 she underwent vaginoplasty and clitoral reduction and made good recovery. She has been stable on hydrocortisone 10 mg in the morning, 12.5 mg in the evening and fludrocortisone 50 mcg once daily (Testosterone<0.7 mmol/l (0.53.0), 17-hydroxy progesterone=1.0 nmol/l (1.010), DHEA-sulfate <0.4 pmol/l and normal FSH and LH). In February 2006, she presented to our accident and emergency department with tiredness, vomiting and generally being unwell for 10 days. She was significantly dehydrated, acidotic and had plasma glucose of 55, with significant ketonuria. She was treated for Diabetic ketoacidosis in the High Dependency Unit and made good recovery. She is presently on a basal bolus regime, along with her regular dose of hydrocortisone and fludrocortisone.
21-hydroxylase deficiency, accounting for 9095% of all congenital adrenal hyperplasia (CAH), is characterised by insufficient cortisol synthesis and androgen excess. Dependant on the extend of enzyme impairment classic CAH is subdivided into salt wasting (deficient in both aldosterone and cortisol) and simple virilising with mainly cortisol deficiency. Androgen excess in both conditions results in virilisation of external genitalia in females. The therapeutic spectrum of glucocorticoids is narrow, and supraphysiological doses, often needed to suppress adrenal androgens, bring a risk for adiposity, insulin resistance and osteoporosis. Indeed, a progressive increase in fat mass during childhood has been reported in CAH patients. Elevated androgens may lead to insulin resistance. The high frequency of gestational diabetes among CAH patients indicates, however high risk of future diabetes. Certainly there is a need for long term follow up and further studies of insulin sensitivity in CAH. There are only few reported cases in the literature of type 1 diabetes in association with 21-hydroxylase deficiency congenital adrenal hyperplasia.