CASI CLINICI   

Gazzetta Medica Italiana Archivio per le Scienze Mediche 2014 July-August;173(7-8):427-30

Copyright © 2014 EDIZIONI MINERVA MEDICA

lingua: Inglese

Subacute thyroiditis causing fever of unknown origin: a case report

Liu Y. M. ^{1, 2}

¹ Department Infectious Disease, Changhua Christian Hospital, Changhua, Taiwan; ² Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan

Endocrine causes of fever of unknown origin may be difficult to discover when they mimic other disorders that are more common. Endocrine causes of fever cited in the literature include thyrotoxicosis, subacute thyroiditis, adrenal insufficiency, and pheochromocytoma. Among these causes, subacute thyroiditis is often overlooked. I reports the case of a 41-year-old woman with initial complaints of night fever and sweats for 2 weeks after developing sore throat. Physical examination revealed thyroid gland enlargement but no tenderness. Minocycline was prescribed initially due to suspicion of Q fever and leptospirosis but her fever and cold sweating did not improve. Subsequent testing revealed a thyroid-stimulating hormone (TSH) level of 0.008 IU/L. Her free T4 level was 1.74 ng/dL (reference range, 0.7-1.48 ng/dL), T4 level was 12.37 µg/dL (reference range, 4.87-11.72 µg/dL), and T3 level was 1.08 ng/mL (reference range, 0.58-1.59 ng/mL). Her antithyroglobulin antibody levels were elevated at 1:400 times. TSH-binding inhibitory immunoglobulin percent was 17.2% (reference range, <15%). Her erythrocyte sedimentation rate (ESR) was 132 mm/h (reference range, 0-25 mm/h).A Tc-99m thyroid scan showed diffusely decreased uptake. She was treated with diclofenac (25 mg) 3 times daily and became afebrile after treatment. Subacute thyroiditis should be considered a possible cause of fever of unknown origin even if signs of hyperthyroidism and thyroid tenderness are absent.