Graves’ Disease Presenting as Adrenal Crisis in a Patient With Congenital Adrenal Hyperplasia

Background: Adrenal crisis (AC) is a life-threatening condition that occurs either as the initial presentation of adrenal insufficiency or in patients who are known to have hypoadrenalism, when a precipitating acute stressor outweighs the mineralocorticoid and glucocorticoid supply. It is known that exposure to high levels of thyroid hormones in the presence of hypoadrenalism may precipitate AC.Graves’ disease (GD), as a precipitant of AC in patients with congenital adrenal hyperplasia (CAH), has been rarely described in the literature. Clinical Case: A 15-year-old male with classic CAH diagnosed since birth when he had vomiting and darkly pigmented skin. He was on regular follow-up with his endocrinologist in his home country. For an unclear reason, he was on hydrocortisone 40 mg daily in divided doses. The patient presented to the emergency department with nausea, vomiting, loose stool, dizziness, and fatigue for 5 days. On examination, he was conscious and oriented but looked tired. He had a temperature of 36.8°C, blood pressure (supine) 132/78 mmHg (standing blood pressure could not be taken because the patient was dizzy), pulse rate 130/minute, and respiratory rate 17/minute. Otherwise, the physical exam was unremarkable. Initial laboratory investigations showed sodium 114 (136–145 mmol/L), potassium 6.0 (3.5–5.1 mmol/l), chloride 83 (102–104 mmol/L) and Bicarbonate 14 (22–29 mmol/L). Serum creatinine, complete blood count, C-reactive protein (CRP) and procalcitonin levels were within normal. He was treated for AC with stress doses of hydrocortisone intravenously, and normal saline intravenous infusion. He showed a gradual improvement of his symptoms with normalization of the electrolytes. Thus, he was switched to oral hydrocortisone replacement 15 mg am and 10 mg in the afternoon. Nevertheless, his pulse rate was 105 -110 / min. Therefore, thyroid function test (TFT) was done and revealed TSH 0.3 (0.5–4.3 mIU/L) and FT4 30.6 (12.9–20.6 pmol/L). Thyroid uptake scan showed a mildly enlarged thyroid gland with homogeneous and slightly increased radiotracer uptake suggestive of GD. Thus, propranolol and carbimazole were prescribed in addition to hydrocortisone. Then, the patient was discharged after proper education about precipitating factors of AC. Later on, the patient appeared for his clinic appointment, he was clinically well with normal vital signs, serum electrolytes, and TFT. Propranolol was stopped, carbimazole dose was adjusted, and he was maintained on hydrocortisone. Conclusion: Unrecognized Graves’ disease was the precipitating factor of the adrenal crisis in this patient with CAH. Despite the rarity of the association, a high index of clinical suspicion for unusual acute stressors is very important for proper management of AC and to prevent future recurrence.