title: Subacute thyroiditis manifesting as fever of unknown origin.
abstract: Subacute thyroiditis (SAT) usually occurs in women in middle age with a viral prodrome, thyroid or neck tenderness, classic symptoms of thyrotoxicosis, and elevated erythrocyte sedimentation rate (ESR). We report a case in an 81-year-old man who initially had 2 days of fever to 101.2 degrees F, confusion, and bilateral lower extremity weakness. Extensive evaluation was remarkable only for the following laboratory values: thyrotropin (TSH) 0.02 microIU/mL, free thyroxine (FT4) 3.1 ng/dL, free triiodothyronine (FT3) 6.0 pg/mL, and ESR 98 mm/hr. One week later, the patient had persistent fevers to 102 degrees F; no source was found. The fever resolved, and 3 months later the patient had profound hypothyroidism (TSH >44.0 microIU/mL, FT4 0.4 ng/dL, ESR 13 mm/hr). A painless thyroid gland and atypical manifestations of hyperthyroidism are unusual in SAT. When fever is of unknown origin, SAT should be considered even if classic features are absent.
authors.affiliation: Department of Medicine, Brooke Army Medical Center, Fort Sam Houston, Tex 78234-6200, USA.
authors.forename: B M
authors.initials: BM
authors.lastname: Weiss
authors.forename: M J
authors.initials: MJ
authors.lastname: Hepburn
authors.forename: D P
authors.initials: DP
authors.lastname: Mong
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001799:Blood Sedimentation; D003221:Confusion / Q000209:etiology; D003937:Diagnosis, Differential; D005335:Fever of Unknown Origin / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000175:diagnosis; D007866:Leg; D008297:Male; D018908:Muscle Weakness / Q000209:etiology; D013968:Thyroiditis, Subacute / Q000150:complications / Q000175:diagnosis*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
chemical_list: D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine