We present the case of a woman who first presented at age 18 with hirsutism. Menarche had been normal and she had regular menses. She gave no past medical history except that at age 6 she had been admitted to hospital with tonsillitis that was complicated by diarrhoea and vomiting, drowsiness and hypotension. At that time, Na+ was 130 mmol/l and K+5.8 mmol/l. She was treated with antibiotics and fluids and improved; electrolytes returned to normal.
On examination her blood pressure was 140/105 mmHg. She had acne but no features of virilisation; her BMI was 20.8 kg/m2.
Routine biochemistry was normal. Two random measurements of 17 hydroxy-progesterone (17-OHP) were raised at 47 and 55 nmol/l (1.412). Synacthen stimulation resulted in an increase of 17-OHP from 72 to 79 nmol/l and then 88 nmol/l at 30 and 60 min respectively. Peak cortisol response was suboptimal at 412 mmol/l. DHEAS was high at >26 μmol/l (1.810.2) with a high testosterone 5.1 nmol/l (1.43.8). A 24 h urine collection showed normal cortisol excretion at 498 nmol/24 h and cortisol suppressed after overnight dexamethasone of 1 mg.
A diagnosis of non-classical heterozygous congenital adrenal hyperplasia was made and she was started on prednisolone 2.5 mg in the morning and 5 mg at night.
Her hirsutism improved and due to over-suppression of 17-OHP, prednisolone was tapered and eventually stopped 9 years later at age 27. A repeat short synacthen test (SST) showed a 17-OHP peak of 20.0 nmol/l and a cortisol peak of 500 nmol/l, again suboptimal. She also tested negative for known 21-hydroxylase mutations and repeat androgen levels had normalised.
Repeated SSTs have resulted in suboptimal cortisol response but normal 17OHP responses but with no clinical features of androgenisation or hypoadrenalism. We have no explanation for the resolved abnormalities but she remains well having declined long term steroid therapy and has steroids at times of illness.