Fever of unknown origin: Subacute thyroiditis versus typhoid fever

Fever of Unknown Origin: A Clinical Approach

“…33,34 Neck/jaw pain, easily dismissed as dental pain, may be a clue to subacute thyroiditis. [35][36][37][38] Factitious fever should be considered in medical personnel. 39 Specifically inquire about inflammatory bowel disease (regional enteritis), alcoholism (cirrhosis), and medications (pseudolymphoma, drug fever).…”

Fever of unknown origin (FUO): de Quervain's subacute thyroiditis with highly elevated ferritin levels mimicking temporal arteritis (TA)

“…[3][4][5][11][12][13][14][15] In the case presented, a 55-year-old woman had historical findings that suggested TA (ie, bitemporal headaches and bilateral angle of the jaw pain). Nonspecific laboratory test results also were consistent with the diagnosis of TA (ie, a highly elevated ESR).…”

“…3,[7][8][9] Among the miscellaneous causes of FUO are endocrine disorders that may cause fever in a small group of patients. 4,5,[10][11][12][13][14][15] Adrenal insufficiency, pheochromocytomas, and hyperthyroidism are rare causes of FUO because clinical findings usually suggest the diagnosis. 8,10 In the past, etiocholanolone fevers were occasionally cited as potential causes of FUO, but this potential cause of FUO is no longer recognized in the FUO differential diagnosis.…”

“…8,10 A rare endocrine cause of FUO is subacute thyroiditis. 4,5,[11][12][13][14][15] Subacute thyroiditis is usually a fairly straightforward diagnosis. However, if a patient with subacute thyroiditis has a history and physical and nonspecific laboratory findings that suggest an alternate diagnosis, then subacute thyroiditis can be a difficult FUO diagnosis.…”

Uncommon Causes of Thyrotoxicosis

“…The hallmark of this variant is a painful and tender thyroid after a viral prodrome of myalgias, pharyngitis, low-grade fever, and fatigue (90)(91)(92). The most accepted etiology of subacute thyroiditis is a viral illness.…”