TB or not to be? Kikuchi-Fujimoto disease: a rare but important differential for TB

A 29-year-old British Pakistani woman presented with a 2-month history of drenching fevers, night sweats, lethargy and tender cervical and axillary lymphadenopathy. Initial investigations, bloods and imaging were unremarkable. Fever persisted during her admission, and treatment for tuberculosis (TB) lymphadenitis was started postbiopsy until histology confirmed a diagnosis of Kikuchi-Fujimoto's disease (KFD). KFD has a non-specific presentation of fever, night sweats and lymphadenopathy and commonly raises a clinical suspicion of a number of other serious conditions such as TB, lymphoma, HIV, systemic lupus erythematous, toxoplasmosis and infectious mononucleosis. Although rare, KFD should be considered to be a differential diagnosis for fever of unknown origin and tender lymphadenopathy in otherwise well individuals. This case demonstrates the importance of a timely histological biopsy diagnosis to prevent an incorrect diagnosis and administration of unnecessary medications.