Clinical analysis of fever of unknown origin in children: A 10-year experience in a northern Taiwan medical center

BACKGROUND: Fever of unknown origin (FUO) was first described in 1961 as fever >38.3°C for at least 3 weeks with no apparent source after 1 week of investigations in the hospital. Infectious disease comprises the majority of cases (40-60%). There is no related research on FUO in children in Taiwan. The aim of this study is to determine the etiologies of FUO in children in Taiwan and to evaluate the relationship between the diagnosis and patient's demography and laboratory data. METHODS: Children under 18 years old with fever >38.3°C for >2 weeks without apparent source after preliminary investigations at Taipei Veterans General Hospital during 2002-2012 were included. Fever duration, symptoms and signs, laboratory examinations, and final diagnosis were recorded. The distribution of etiologies and age, fever duration, laboratory examinations, and associated symptoms and signs were analyzed. RESULTS: A total of 126 children were enrolled; 60 were girls and 66 were boys. The mean age was 6.7 years old. Infection accounted for 27.0% of cases, followed by undiagnosed cases (23.8%), miscellaneous etiologies (19.8%), malignancies (16.6%), and autoimmune disorders (12.7%). Epstein-Barr virus (EBV) and cytomegalovirus (CMV) were the most commonly found pathogens for infectious disease, and Kawasaki disease (KD) was the top cause of miscellaneous diagnosis. CONCLUSIONS: Infectious disease remains the most common etiology. Careful history taking and physical examination are most crucial for making the diagnosis. Conservative treatment may be enough for most children with FUO, except for those suffering from malignancies.