Is hydrocortisone (corticosteroid) given to patients with Varicella Zoster Virus (VSV) infection and a suspected allergy to aciclovir (antiviral medication)?

Management of VZV Infection with Suspected Aciclovir Allergy

If a patient with VZV infection has a suspected allergy to aciclovir, hydrocortisone (or other corticosteroids) should NOT be given as a substitute for antiviral therapy; instead, you should pursue aciclovir desensitization or use alternative antiviral agents like foscarnet. 1

Understanding the Clinical Context

The question conflates two separate clinical issues that must be addressed independently:

• Antiviral therapy for VZV infection (which aciclovir addresses)
• Adjunctive corticosteroid therapy (which serves a different purpose)

Hydrocortisone cannot replace aciclovir's antiviral activity. 2, 3

Primary Management: Addressing the Aciclovir Allergy

First-Line Approach: Aciclovir Desensitization

For patients with VZV encephalitis who have no alternative treatment options, intravenous aciclovir desensitization should be performed under specialist supervision. 1

• A successful case report demonstrated that a patient with HSV-1 encephalitis who developed severe allergic reaction to aciclovir was successfully treated using an intravenous desensitization protocol. 1
• The allergic symptoms initially regressed with methylprednisolone treatment after aciclovir discontinuation, but definitive treatment required desensitization to allow completion of antiviral therapy. 1
• This represents the first adult case in the literature treated with intravenous aciclovir desensitization. 1

Alternative Antiviral: Foscarnet

If desensitization is not feasible or fails, foscarnet (90-100 mg/kg/day IV) is the alternative antiviral agent for VZV infection in patients who cannot receive aciclovir. 4, 5

• Foscarnet has been used successfully in immunocompromised patients with VZV infection when aciclovir resistance or intolerance occurs. 4, 5
• Dosing is typically 90-100 mg/kg/day for 8-21 days depending on severity. 5

Role of Corticosteroids in VZV Encephalitis

When Corticosteroids ARE Indicated

Corticosteroids may be beneficial as adjunctive therapy in VZV encephalitis, particularly when there is a vasculitic component or stroke, but only alongside appropriate antiviral therapy. 6, 3, 7

• The Infectious Diseases Society of America gives a B-II recommendation for corticosteroids as adjunctive therapy in VZV encephalitis with vasculopathy. 7
• A short course of prednisolone 60-80 mg daily for 3-5 days is often given due to the inflammatory nature of VZV encephalitis lesions. 6
• This differs from HSV-1 encephalitis, where routine steroid use is not recommended. 6, 7

Critical Caveat

Corticosteroids should NEVER be used as monotherapy or as a substitute for antiviral treatment in VZV infection. 2, 3

• Immunosuppression from corticosteroids could theoretically facilitate viral replication if given without concurrent antiviral coverage. 6, 7
• Steroids address inflammation and edema, not viral replication itself. 6

Clinical Algorithm for VZV with Suspected Aciclovir Allergy

1. Confirm the allergy: Determine if the reaction is true IgE-mediated hypersensitivity versus other adverse effects (e.g., crystalluria-induced nephropathy). 2

2. Assess severity of VZV infection:

   • Encephalitis or disseminated disease requires urgent antiviral therapy. 3
   • Localized dermatomal zoster may allow more time for allergy evaluation. 5

3. Choose antiviral strategy:

   • Preferred: Aciclovir desensitization protocol under specialist supervision. 1
   • Alternative: Foscarnet 90-100 mg/kg/day IV. 4, 5

4. Consider adjunctive corticosteroids ONLY if:

   • VZV encephalitis with vasculitic component is present. 6, 3, 7
   • Antiviral therapy is already initiated or will be given concurrently. 6, 7
   • Prednisolone 60-80 mg daily for 3-5 days. 6

Common Pitfalls to Avoid

• Never use corticosteroids alone without antiviral coverage in active VZV infection, as this could worsen viral replication. 6, 7
• Do not confuse aciclovir's renal toxicity (crystalluria causing obstructive nephropathy) with true allergic reactions; the former requires dose adjustment and hydration, not drug discontinuation. 2
• Do not assume all antiviral adverse effects are allergies; many are dose-related and manageable with supportive care. 2
• Recognize that VZV encephalitis management differs from HSV-1 encephalitis regarding corticosteroid use; VZV has a clearer role for steroids due to vasculitic pathophysiology. 6, 7