Letter to the Editor - Fever of Unknown Origin in Internal Medicine

Sir,
We read with interest the article by Kejariwal et al¹ and wish to share our experience on the same subject. We reviewed analysed 82 patients with a fever of unknown origin (FUO), diagnosed according to the definition of Petersdorf and Beeson, between 1980 and 1999 in a training hospital. The mean age of the patients was 39 years (range 17-87 years). Infection was the principal cause (59%), followed by neoplasm (10.9%), collagenoses/vasculitis (7%) and miscellaneous diseases (2.4%). Sixteen (20.7%) of the FUO cases remained undiagnosed. In the infection group, brucellosis (11 cases, 13%) and tuberculosis (10 cases, 12%) were the commonest. Lymphoma was the most common cause of neoplasm. Systemic lupus erythematosus, polyarteritis nodosa and Still's disease were causes of FUO in 25%, 21% and 17% of collagenoses/vasculitis group. Clinical recovery occurred in 47 (57.3%) patients, clinical condition remained unchanged in 30 (36.5%) patients and death was observed in 5 (6.2%) patients.