Long-term exposure to cortisol carry health risk and its important to establish the cause and exclude exogenous steroid use before starting investigation for endogenous causes, we present a young man with clinical picture of Cushing but low random cortisol.
16 years old studying for his AS examinations at the time, presented to his GP with 5-week history of fatigue, weight gain of 2 stone in 18 months, insomnia, diarrhoea, left sided abdominal pain, reduced concentration, loss of appetite, dizziness and occasional headache.
On examination; BMI of 29.1, normal blood pressure, moon face and multiple striae over his trunk, axillae and abdomen. His visual fields were intact.
Initial investigation by GP; showed 9am cortisol of 100 followed by suboptimum short Synacthen test, he had been started on replacement dose Hydrocortisone (HC) and appointment booked with endocrine.
Seen in endocrine clinic, symptoms had not improved on HC, felt to have Cushingoid features clinically, Steroid had been gradually stopped and repeated testing 2 weeks later showed 9am cortisol of 192, Overnight Dexamethasone suppression cortisol less than 20, normal MRI Pituitary and Urinary steroid profile. He manages to lose five kg in weight.
We had a patient with Clinical appearance of Cushings and suboptimal biochemistry our working diagnosis include cyclic Cushings and exogenous steroid use based on clinical pictures and very low base line cortisol on his initial short Synacthen test. Patient had denied substance misuse on multiple occasions. patient had been asked not to cut his hair and a hair sample had been sent for steroid testing. preliminary result had showed high level of steroid for two consecutive months. We aware that hair test may not differentiate cyclic Cushing from exogenous use and our plan is to follow him clinically with repeated testing.