Chen Y.-S.Su D.-H.Hsiao Y.-L.TIEN-CHUN CHANG2020-06-032020-06-0320041016-7390https://www.scopus.com/inward/record.uri?eid=2-s2.0-1942499780&partnerID=40&md5=f63cbb64f3b5c02cc6cabdee78b783f5https://scholars.lib.ntu.edu.tw/handle/123456789/496671Subacute thyroiditis (SAT) is often overlooked and misdiagnosed as pharyngitis, but well documented cause of fever of unknown origin. We hereby reported a case of fever of unknown origin in a 42-year-old female with SAT. She presented with high fever for more than two weeks and previous history of upper respiratory infection, followed by thyrotoxicosis. After the examinations of thyroid sonography and fine needle aspiration cytology (FNAC), the diagnosis of SAT was confirmed. She was administrated with prednisolone. The symptoms and signs were improved dramatically. The clinical manifestations of SAT are painful thyroid, a rise in ESR and thyroglobulin, depressed RAIU and echoic hypogenisity. Depending on the physician's attitude and local availability, FNAC, ultrasound or scintigraphy may support the diagnosis. Although SAT is a self-limited disease, the purpose of medications is for relief of symptom only. Therapy with antithyroid agents and antibiotics is not suggested. The reason for follow-up of SAT is to survey the relapse and permanent hypothyroidism. Physical examination and thyroid sonography and FNAC are the convenient methods for the physician to follow up and further management of SAT.Fine needle aspiration cytology; Subacute thyroiditis; Thyroid ultrasonography; Thyrotoxicosis[SDGs]SDG3antibiotic agent; antithyroid agent; glucocorticoid; prednisolone; radioactive iodine; thyroglobulin; adult; article; aspiration biopsy; case report; erythrocyte sedimentation rate; female; fever; follow up; human; human tissue; hypothyroidism; physical examination; physician attitude; pyrexia idiopathica; recurrence risk; subacute thyroiditis; symptomatology; thyroid scintiscanning; thyrotoxicosis; treatment outcome; ultrasound; upper respiratory tract infectionjournal article2-s2.0-1942499780