Type II polyglandular autoimmune syndrome: a case of Addison's disease precipitated by use of levothyroxine.

A 46-year-old woman was referred to the endocrinology clinic for evaluation of progressive fatigue, dizziness and treatment-resistant hypothyroidism. Initial laboratory results revealed hypothyroidism, hyponatraemia and hyperkalaemia. Liothyronine sodium (Cytomel) was initiated, which exacerbated her fatigue and dizziness. Suspecting adrenal insufficiency, an 08:00 cortisol level was obtained and found to be low with failure to increase following cosyntropin stimulation test. Diagnosis of primary adrenal insufficiency was confirmed via CT abdomen and pelvis revealing diminutive adrenal glands and elevated 21-hydroxylase antibody. Treatment was initiated with hydrocortisone 10 mg every morning and 5 mg at 16:00/day, with plan for patient follow-up in 3 weeks to assess need for mineralocorticoid replacement. Polyglandular syndromes are rare and have a wide variety of presentation. Thus, we recommend screening patients with a single autoimmune disorder who do not respond to conventional therapy to prevent possible life-threatening adrenal crisis.