Retrospective study of 744 children with fever of unknown origin

Abstract

Objective To investigate the etiology, diagnostic methods and procedures for management of fever of unknown origin (FUO) in children. Methods All 744 children with fever of unknown origin admitted to Beijing Children's Hospital between January 1, 1993 and December 31,1998 were divided into three groups according to age, group 1: younger than 3 years; group 2: between 3 and 7 years; group 3: older than 7 years. Medical records were reviewed retrospectively. Results There were 417 boys and 327 girls with an average of 7.2years (from 14 days to 14 years) . (1) In group 1,50 cases among 96 children (52%) had infectious diseases with 21 cases (22%) of respiratory tract infections; 15 cases and 9 cases of 96 (16% and 9%) had miscellaneons disonders and neoplasm with 14 cases (15%) of congenital diseases and 4 cases (4.2%) of malignant histiocytosis, respectively. Collagen vascular diseases were found in 5 cases (5%) , and in 17 (18%) of 96 cases no diagnosis could be made. (2) In group 2,115 cases among 192 children (59.9%) had infectious diseases with 38 cases (19.8%) of respiratory tract infections; 28 cases and 11 cases of 192 (14.6% and 5.7%) had collagen vascular diseases and neoplasm with 26 cases (13.5%) and 6 cases (3.1%) of juvenile rheumatoid arthritis and leukemia, separately. Miscellaneous disorders were found in 10 cases (5.2%) and in 28 (14.6%) of 192 cases no diagnosis could be made. (3) In group 3,305 of 456 children (66.9%) had evidences of infectious diseases with 102 cases (22.4%) of respiratory tract infections; 69 and 15 of 456 (15.1% and 3.3%) cases had collagen vascular diseases and neoplasm and 37 cases (8.1%) and 8 cases (1.8%) had juvenile rheumatoid arthritis and leukemia, respectively. Miscellaneous disorders were confirmed in 15 of 456 (3.3%) cases with 11 cases (2.4%) of subacute necrotizing lymphadenitis, and no diagnosis could be made in 52 of 456 (11.4%) cases. History, physical examination and routine laboratory studies led to a final diagnosis in 39.9% (297/744) of all cases. Ultrasonography, CT scan, bone marrow examination and biopsy contributed to the diagnosis in 3.4%, 3.7%, 8.5% and 71.1% of the cases, separately. Conclusions Infectious diseases, congenital diseases with disturbances in temperature regulation and neoplasm were the three major causes of FUO in children younger than three years of age. Infectious disease, collagen vascular disease and neoplasm were the three most frequent causes of FUO in children older than 3 years of age. Respiratory tract infection was the leading cause in each group. Juvenile rheumatoid arthritis and leukemia dominated the collagen vascular disease and neoplasm, and subacute necrotizing lymphadenitis was found in a small proportion of the two groups older than 3 years of age. A thorough history of disease, full physical examination of the patient and routine laboratory studies, especially erythrocyte sedimentation rate and C-reactive protein were very important in diagnosing the etiology of fever of unknown origin. The use of non-invasive imaging techniques and invasive methods may be helpful to indiagnosis. Key words: Fever of unknown origin; Diagnosis; Child