Cerebrospinal fluid patterns in different causes of viral meningitis in children

CSF: cerebrospinal fluid; WBC: white blood cell; RBC: red blood cell; ↑: elevated; ↓: decreased; NL: normal; SL: slightly.
* In most cases of viral meningitis, the CSF WBC is within the range of 10 to 500 cells/microL, though higher values can be seen with some viruses. Normal CSF WBC counts can be seen in enteroviral meningitis, particularly in young infants. Normal CSF WBC can also rarely be seen in herpes simplex virus meningoencephalitis early in the course of infection. In most cases of viral meningitis, there is a mononuclear-predominant pleocytosis, although a neutrophil predominance has been described early in the course of enteroviral meningitis (ie, within the first 24 to 48 hours). For additional details, refer to UpToDate content on CSF interpretation in children with viral meningitis.