What is the likely causative virus and optimal treatment, including the use of steroids and Intravenous Immunoglobulin (IVIG), for a patient with viral meningitis?

Viral Meningitis: Causative Viruses and Treatment

Direct Answer

For viral meningitis, steroids and IVIG are NOT recommended—the standard of care is supportive treatment only with analgesia and fluids. 1, 2

Most Common Causative Viruses

Enteroviruses are the predominant cause, accounting for 50-80% of all viral meningitis cases and 85-95% of aseptic meningitis. 1, 3, 4

Other important viral causes include:

• Herpes simplex virus type 2 (HSV-2) - the most common cause of recurrent viral meningitis 1, 5, 6
• Varicella zoster virus (VZV) 1
• HSV-1 (less common than HSV-2 for meningitis) 1
• Arboviruses, mumps, lymphocytic choriomeningitis virus, and influenza viruses (rare causes) 3

Why Steroids and IVIG Are NOT Recommended

Steroids

There is no evidence supporting corticosteroid use in viral meningitis. 7, 1

The only exceptions where steroids may be considered are:

• VZV vasculopathy (stroke-like presentation) - where corticosteroids are sometimes used alongside aciclovir, though evidence is limited 7
• VZV encephalitis - where a short course (e.g., 60-80 mg prednisolone daily for 3-5 days) may be given due to the inflammatory nature of the lesion 7

Critical distinction: The evidence for steroids in bacterial meningitis (particularly pneumococcal) is strong 8, but this does NOT apply to viral meningitis—do not confuse these two conditions.

IVIG (Intravenous Immunoglobulin)

IVIG has no proven benefit in viral meningitis and is not recommended for routine use. 7

The only scenarios where IVIG has been mentioned (without randomized trial evidence):

• Chronic enterovirus meningitis in immunocompromised patients (e.g., agammaglobulinemia) 7
• Severe enterovirus 71 infection 7

For typical viral meningitis in immunocompetent patients, IVIG offers no benefit and should not be used. 7

Recommended Treatment Approach

Standard Management Algorithm

1. Provide supportive care with analgesia for headache and other symptoms 1, 2
2. Ensure adequate hydration with IV or oral fluids as needed 1
3. Discontinue antibiotics once viral diagnosis is confirmed by CSF PCR 1, 9, 2
4. Expedite hospital discharge once diagnosis is established 1, 2

Antiviral Therapy Considerations

For enterovirus meningitis (the most common cause): No specific antiviral therapy is available or recommended—supportive care only. 7, 1

For HSV or VZV meningitis: Despite theoretical benefits, there is no evidence supporting aciclovir or valaciclovir treatment for uncomplicated meningitis. 1, 2

Exception for first-episode HSV-2 meningitis: Some clinicians use IV aciclovir 10 mg/kg every 8 hours until fever and headache resolve, followed by oral valacyclovir 1 gram three times daily to complete a 14-day course, though this practice lacks strong evidence. 2, 6

Critical Pitfall: Do Not Miss Encephalitis

If there are ANY signs of altered mental status, personality changes, behavioral changes, or cognitive impairment, immediately initiate IV aciclovir 10 mg/kg every 8 hours for presumed HSV encephalitis. 1, 2

• Preserved consciousness is the key distinguishing feature of viral meningitis 9
• Any alteration in mental status suggests encephalitis or other serious pathology requiring immediate antiviral treatment 9, 2

Special Considerations

Recurrent HSV-2 Meningitis

Prophylactic aciclovir/valaciclovir is NOT recommended for preventing recurrent HSV-2 meningitis. 1, 2

• A placebo-controlled trial showed that valaciclovir 500 mg twice daily did not reduce recurrent episodes and was associated with increased relapse risk after discontinuation 1, 2
• Episodes can occur months to years apart with complete recovery between episodes 1

Pleconaril for Enterovirus

Pleconaril may be considered in severe enterovirus disease, but it is not widely available and not routinely recommended. 7

• In phase III trials, it reduced headache duration by approximately 2 days compared to placebo 7
• It has not been studied in enterovirus encephalitis 7

Follow-up and Prognosis

Assess all patients for potential long-term sequelae before discharge, including headaches (most common, affecting up to one-third), fatigue, sleep disorders, and emotional difficulties. 1

Viral meningitis is rarely fatal in immunocompetent adults, with most patients making full recovery, though some experience persistent symptoms. 1

• Patients may need staged return to work or studies 1
• Follow-up care should be offered as issues often become apparent only after discharge 1

Summary Algorithm

1. Confirm viral meningitis via CSF PCR (enterovirus, HSV-1, HSV-2, VZV) 1, 9
2. Assess mental status carefully:
   • Normal consciousness → supportive care only 1, 2
   • Any altered mental status → treat as encephalitis with IV aciclovir 1, 2
3. Do NOT use steroids or IVIG for routine viral meningitis 7, 1
4. Stop antibiotics and expedite discharge once viral etiology confirmed 1, 2
5. Provide analgesia, hydration, and reassurance about prognosis 1