Negative C-reactive protein in children with bacterial infection

Purpose: To evaluate the practical value of initial C-reactive protein (CRP ) in the diagnosis of bacterial infection in children. Methods: The subjects comprised 11 children, six boys and five girls, aged 3 months through to 3 years (median age 16 months), whose initial CRP level s were < 1.0 mg/dL despite bacterial infection. C-reactive protein was quan titated at the first medical examination by nephelometry. Results: The diagnosis was urinary tract infection (n=4), bacterial meningi tis (n=2), sepsis (n=2), pneumonia (n=2) and arthritis of the hip joint (n= 1). The CRP levels were significantly elevated during the course of infecti on, ranging from 7.6 to 28.5 mg/dL. The bacterial etiology was non-specific . Eight patients were examined within 12 h of onset, three exhibited negati ve CRP values despite the duration of the insult over 12 h. Six patients we re tentatively diagnosed as having a bacterial infection, but the other fiv e were not. Each patient was treated, leading to a favorable outcome withou t any serious complications. Conclusions: Low levels of CRP do not rule out the possibility of bacterial infection in children. The initial value of CRP may be negative, even in p atients with severe bacterial infection or even after 12 h from onset. The data suggest that pediatricians should consistently be aware of the possibi lity of bacterial infection even if the initial CRP test result is negative and that serial CRP measurements appear to be practical.