Treatment of Viral Meningitis
For a patient with viral meningitis confirmed by CSF showing no bacteria, supportive care is the primary treatment approach, with most cases being self-limited and requiring only symptomatic management. 1, 2
Immediate Management
Supportive care is the cornerstone of treatment for viral meningitis. 3, 1 This includes:
- Hydration with intravenous crystalloids to maintain euvolemia 4
- Analgesics for headache management 2
- Antipyretics for fever control 2
- Antiemetics for nausea and vomiting 2
Antiviral Therapy Considerations
If herpes simplex virus (HSV) encephalitis cannot be excluded clinically, intravenous acyclovir 10 mg/kg three times daily should be started within 6 hours of admission and continued pending CSF PCR results. 5, 3 This is critical because:
- HSV meningitis/encephalitis is one of the few viral CNS infections with specific treatment 6
- Early acyclovir administration can prevent progression to encephalitis 3
- Treatment should continue for 14-21 days if HSV is confirmed 5
For varicella-zoster virus (VZV) meningitis, intravenous acyclovir 10-15 mg/kg three times daily with renal dose adjustment is recommended. 5
For recurrent viral meningitis (often HSV-2), early administration of acyclovir, valacyclovir, or famciclovir can shorten episode duration, and daily prophylaxis reduces recurrence frequency. 6
Monitoring and Follow-up
Monitor renal function frequently during acyclovir therapy, as crystalluria-induced renal impairment occurs in up to 20% of patients. 5
Assess for potential sequelae before discharge, including:
- Hearing loss (test if clinically indicated within 4 weeks) 7
- Cognitive deficits 7, 4
- Persistent headaches or fatigue 7
- Psychological impacts, which can be profound and may require mental health referral 7
When to Stop Antibiotics
Discontinue empiric antibiotics once bacterial meningitis is definitively excluded by:
- CSF showing lymphocytic pleocytosis (not neutrophilic) 8
- Negative CSF Gram stain and culture 7
- Negative bacterial PCR if performed 7
- Clinical improvement without antibiotics 2
Common Pitfalls to Avoid
Do not assume all viral meningitis is benign - while mortality is rare in immunocompetent adults, significant morbidity and psychological impacts can occur. 7
Do not delay acyclovir if HSV cannot be excluded - waiting for PCR results before starting treatment can worsen outcomes in HSV encephalitis. 5, 3
Do not forget to assess for immunocompromise - in immunocompromised patients, consider broader viral pathogens including CMV, EBV, and atypical organisms requiring different management. 5
Do not discharge without counseling - patients and families should be informed about expected recovery timeline, potential sequelae, and when to seek re-evaluation. 7
Prognosis
Viral meningitis is generally self-limited with good prognosis in immunocompetent adults. 1, 2 Most patients recover completely within 7-10 days with supportive care alone. 2