Managing fever of unknown origin in adults - BMJ review

Few clinical problems generate such a wide differential diagnosis as pyrexia (fever) of unknown origin. The initial definition proposed by Petersdorf and Beeson in 1961 was later revised. Essentially the term refers to a prolonged febrile illness without an obvious cause despite reasonable evaluation and diagnostic testing.

Definition

Classic adult fever of unknown origin (FUO) is fever of 38.3°C (101°F) or greater for at least 3 weeks with no identified cause after 3 days of hospital evaluation or 3 outpatient visits

Causes of FUO

Common causes of FUO are infections, neoplasms, and connective tissue disorders.

Investigations almost always include imaging studies. Serological tests may be indicated

Treatment of FUO

Empirical antibiotics are warranted only for individuals who are clinically unstable or neutropenic. In stable patients empirical treatment is discouraged, although NSAIDs may be used after investigations are complete. Empirical corticosteroid therapy is discouraged.

References:

Investigating and managing pyrexia of unknown origin in adults. BMJ 2010; 341:c5470 doi: 10.1136/bmj.c5470 (Published 15 October 2010).

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