Differential Diagnosis
- Infectious
- Viral
- EV-B species (includes Group B coxsackieviruses and echoviruses) are the most common cause of aseptic meningitis in both children and adults
- CV-B2 to CV-B5, E-6, E-6, E-9, E-11, E-13, E-16, E-18, E-30, and E-33
- Herpes (especially HSV-2, as primary infection)
- Varicella
- Mumps (encephalitis), measles (acute encephalitis)
- Arboviruses
- Lymphocytic choriomeningitis virus (LCMV)
- Acute HIV
- EBV, influenza, Colorado tick virus, rabies
- Bacterial
- Leptospirosis
- Lyme disease
- Rickettsioses (before onset of fever)
- Other causes of bacterial meningitis after antibiotics
- Mycobacterial
- Fungal
- Non-infectious
- Systemic lupus erythematosus
- Drug-induced meningitis
- IVIg
- Azathioprine
- NSAIDs
- Septra, amoxicillin, isoniazid
- Allopurinol
Investigations
- Enterovirus
- Usually positive PCR of CSF
- Can look for enterovirus in stool, nasopharyngeal, and throat, as well as conjunctiva if there is conjunctivitis
- Persists in stool for several weeks, but less specific
- NP preferred over throat
- Parechovirus PCR if very young child or immunocompromised
- West Nile IgM/IgG/PCR from CSF and blood
- Syphilis screening EIA
- HIV screen
