What is the treatment approach for viral meningitis?

Viral Meningitis Treatment

Viral meningitis requires primarily supportive care with analgesia and fluids, as there are no treatments of proven benefit for most viral causes. 1

Primary Treatment Approach

The cornerstone of management is supportive care, not antiviral therapy. The British Infection Association explicitly states that viral meningitis treatment consists of supportive care with analgesia and fluids, as currently no treatments have proven benefit for most causes 1. This represents a fundamental departure from bacterial meningitis management.

Core Supportive Measures

• Provide adequate analgesia for headache and other symptoms using acetaminophen or NSAIDs (ibuprofen, naproxen), though NSAIDs should be used cautiously as they can rarely cause aseptic meningitis 1, 2
• Ensure adequate hydration with intravenous or oral fluids as clinically indicated 1
• Discontinue antibiotics immediately once viral diagnosis is confirmed by CSF PCR 1
• Expedite hospital discharge once diagnosis is established, as viral meningitis rarely requires prolonged hospitalization 1

Pathogen-Specific Considerations

Enterovirus Meningitis (Most Common)

• Supportive care only - no specific antiviral therapy is available or recommended 1
• Enteroviruses account for the majority of viral meningitis cases (50-80% of all meningitis) 1

HSV Meningitis (Controversial Area)

This is where guidelines diverge significantly. The British Infection Association states there is no evidence supporting acyclovir or valacyclovir for HSV meningitis and recommends supportive care only 1, 3. However, the CDC recommends intravenous acyclovir for HSV-2 meningitis despite acknowledging optimal therapies haven't been studied 3.

In clinical practice, the risk-benefit ratio favors treatment with acyclovir because:

• HSV meningitis can progress to encephalitis with high mortality if untreated 3
• Acyclovir is relatively safe, with main risk being reversible nephropathy preventable with adequate hydration 3
• CSF PCR remains positive for 7-10 days after starting acyclovir, preserving diagnostic yield 3

If treating HSV meningitis:

• Acyclovir 10 mg/kg IV every 8 hours until resolution of fever and headache 3
• Follow with valacyclovir 1g three times daily to complete a 14-day course 3
• Monitor renal function closely and maintain adequate hydration 3

VZV Meningitis

• No evidence supports specific antiviral treatment, similar to HSV meningitis 1
• Supportive care is recommended 1

Critical Distinction: Encephalitis vs Meningitis

If encephalitis is suspected at any point, immediately administer intravenous acyclovir for suspected HSV encephalitis, requiring 14-21 days of IV therapy 1, 3. This is non-negotiable as HSV encephalitis has high mortality without treatment.

Recurrent Viral Meningitis

Most commonly caused by HSV-2, with episodes occurring months to years apart with complete recovery between episodes 1.

Prophylactic acyclovir/valacyclovir is NOT recommended - it did not reduce recurrent HSV-2 meningitis in placebo-controlled trials and may cause rebound after discontinuation 1, 3. This contradicts older literature 4 but represents current best evidence.

Follow-Up and Long-Term Sequelae

All patients require assessment for potential long-term sequelae before discharge 1:

• Headaches occur in up to one-third of patients and are the most common long-term sequela 1
• Fatigue, sleep disorders, and emotional difficulties are common 1
• Staged return to work or studies should be supported, starting part-time initially 1, 2
• Post-discharge follow-up should be offered as many issues only become apparent after discharge 1, 2

Common Pitfalls to Avoid

• Continuing antibiotics after viral diagnosis is confirmed - this increases costs, prolongs hospitalization, and exposes patients to unnecessary risks 1
• Failing to distinguish viral meningitis from encephalitis - encephalitis requires immediate IV acyclovir regardless of pathogen 1, 3
• Prolonged hospitalization - once viral diagnosis is confirmed and patient is stable, expedite discharge 1
• Missing the need for follow-up - long-term sequelae are common and require ongoing management 1

Prognosis

Viral meningitis is rarely fatal in immunocompetent adults, with most patients making full recovery, though some experience long-term sequelae 1. This benign prognosis supports the supportive care approach rather than aggressive antiviral therapy.