We evaluated the C-reactive protein(CRP), white blood cell(WBC) and neutrophil levels in the various infectious diseases in a single hospital.

A total of 640 medical records of children with infectious diseases such as bacterial meningitis(19 cases), acute pyelonephritis(55 cases), measles(253 cases), chicken pox (38 cases), mycoplasma pneumonia(160 cases), tsutsugamushi disease(39 cases) and Kawasaki disease(152 cases) admitted to The Catholic University of Korea, Daejeon St. Mary's hospital from 1996 to 2002 were retrospectively analyzed.

The mean CRP level was 17.9±6.4 mg/dL in bacterial meningitis, 9.1±5.6 mg/dL in Kawasaki disease, and 8.1±3.3 mg/dL in acute pyelonephritis. In the mycoplasma pneumonia and tsutsugamush disease group(atypical bacterial group), the CRP level was 3.2±2.5 mg/dL, and 1.0±0.8 mg/dL in the viral diseases group(measles and chicken pox). There were also significant differences for the WBC count and neutrophil differential between the 3 infectious groups with higher level in the bacterial infections group(15,600±6,100/mm³, 62±21%) than in the atypical bacterial infections and in the viral infections group(9,600±3,300 mm³, 57±11% and 7,300±2,900/mm3, 49±16%, respectively). The inflammatory indices in Kawasaki disease were like those of bacterial infections. There was a correlation between CRP level and WBC or neutrophil count in the bacterial infections and Kawasaki disease groups.

The CRP, WBC and neutrophil levels showed a clear difference between the infectious diseases according to causative agents. The WBC and neutrophil level was different according to age in measles and mycoplasma pneumonia. There was a correlation between CRP level and WBC or neutrophil count in the bacterial infections and Kawasaki disease groups.