Endocrine Abstracts

Introduction: Autoimmune polyglandular syndrome type II is defined by the occurrence of Addison’s disease with thyroid autoimmune disease and/or type I diabetes mellitus.

Case presentation: A seventy-four-years old woman came to the hospital due to fatigue, nausea, vomiting and skin hyperpigmentation that had begun two months ago. On clinical examination, the patient had hyperpigmentation throughout the skin, large dark brown areas on the lips and the buccal mucosa and her blood pressure was 90/60 mm Hg. She had recently been diagnosed with hypothyroidism and had been receiving levothyroxine for two days before admission to the hospital. Her past medical history was otherwise unremarkable.

Laboratory tests revealed hyponatremia (serum sodium: 130 mEq/l), hyperkalemia (serum potassium: 5.56 mEq/l and anemia (hemoglobin: 11.8 g/dl).

Morning blood cortisol level was <0.2 μg/dl and ACTH levels were 1248.0 pg/ml. Addison’s disease was confirmed and antibodies directed against 21-hydroxylase (OH) were positive, a finding suggestive of autoimmune adrenalitis. TSH levels were 6.62 μU/l, T₃: 204.5 ng/dl, FT₄: 1.02 ng/dl, anti-TPO: 314.6 IU/ml, anti-Tg: 613.6 IU/ml.

Autoimmune adrenalitis together with autoimmune thyroid disease was diagnosed, a combination known as autoimmune polyglandular syndrome type II or Schmidt’s syndrome. It seems likely that the prescription of levothyroxine prior to adrenal steroid hormone replacement in this patient with concurrent Addison’s disease precipitated an adrenal crisis.

Conclusions: In hypothyroid patients, careful history taking, thorough clinical examination and laboratory tests should be performed to exclude concurrent Addison’s disease before the initiation of levothyroxine replacement as prescription of levothyroxine prior to adrenal steroid hormone replacement may be hazardous.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.