Abstract

Fever of unknown origin (FUO) is a common manifestation in paediatrics and is a diagnostic problem especially in primary care. The present study aims to revue the causes of FUO in an Iranian referral tertiary care hospital. Information on 95 patients referred to the Children's Medical Center Hospital, Tehran, between 2004 and 2006 with a primary diagnosis of FUO was evaluated retrospectively. Infectious diseases were diagnosed in 26.3 (n = 25) of the cases, while malignant and non-infectious inflammatory diseases constituted 7.4 (n = 7) and 14.7 (n = 14), respectively. Urinary tract infections, acute lymphoid leukaemia and Kawasaki disease were the most commonly diagnosed conditions. Urinary tract infection accounted for approximately half of the infectious cases (n = 14). Conclusive diagnostic factors included history and examination in 21 cases, analysis of different specimens (i.e., urine analysis, urine culture, serology, peripheral blood and cerebrospinal fluid CSF examination) in 12 cases, culture in nine cases and serological tests in four cases. Infection and malignancy in patients aged under three years, and inflammatory diseases in patients aged over three years were more common. In patients aged under three years urine culture, bone marrow aspiration and peripheral blood smear proved more helpful in arriving at a final diagnosis of FUO, while in patients aged over three years, history and physical examination also contributed to the final diagnosis.