The duration of febrile seizures and peripheral leukocytosis.

In 203 consecutive children with febrile seizures, no clear association (odds ratio = 1.0 [95% CI, 0.9-1.1], P = .59) was found between seizure duration and blood leukocytosis (> or = 15.0 x 10(9) cells/L). Increased leukocyte counts may be misinterpreted because of seizure duration. In children with febrile seizures, leukocyte counts should be used to evaluate the underlying cause of fever.