How to manage itching from herpes zoster (shingles)?

Management of Itching from Shingles (Herpes Zoster)

For itching associated with herpes zoster (shingles), a combination of antiviral therapy and symptomatic treatment is recommended, with oral antihistamines, topical calamine lotion, and cool compresses being the most effective first-line options for symptom relief.

Antiviral Therapy

Antiviral therapy is the foundation of shingles treatment and can indirectly help reduce itching by accelerating healing:

• Start antiviral therapy as soon as possible (ideally within 72 hours of rash onset) to reduce viral replication and accelerate lesion healing 1
• Recommended antiviral options:
  • Famciclovir 500 mg three times daily for 7 days 2
  • Valacyclovir 1000 mg three times daily for 7 days
  • Acyclovir 800 mg five times daily for 7 days

Early antiviral treatment not only reduces acute symptoms including itching but also decreases the risk of postherpetic neuralgia 3.

Direct Management of Itching

First-line options:

1. Topical treatments:

   • Calamine lotion applied to affected areas several times daily
   • Cool compresses with clean, cool water for 20 minutes several times daily
   • Colloidal oatmeal baths for widespread itching

2. Oral antihistamines:

   • Diphenhydramine (Benadryl) 25-50 mg every 4-6 hours as needed
   • Non-sedating alternatives: cetirizine 10 mg daily or loratadine 10 mg daily

Second-line options:

1. Topical anesthetics:

   • Lidocaine patches 5% applied to intact skin near lesions (not directly on open lesions)
   • Topical benzocaine preparations

2. For severe itching:

   • Short course of oral corticosteroids (in addition to antivirals) may help reduce inflammation and associated itching in immunocompetent patients
   • Gabapentin starting at 300 mg daily and titrating up as needed may help with neuropathic itching

Special Considerations

Immunocompromised Patients

• Higher doses of antivirals may be needed 1
• Intravenous acyclovir may be required for severe cases
• More aggressive symptom management may be necessary

Elderly Patients

• May experience more severe itching and pain
• Dosage adjustments for antivirals may be needed based on renal function 2
• Monitor for side effects of antihistamines, particularly anticholinergic effects

Prevention of Secondary Infection

• Keep lesions clean and dry
• Avoid scratching to prevent bacterial superinfection
• If signs of secondary infection develop (increased redness, swelling, purulent drainage), antibacterial treatment may be needed

Important Caveats

1. Do not use topical antivirals for itching - they have minimal effect on symptom relief and poor skin penetration

2. Avoid topical antihistamines - they can cause contact dermatitis and worsen symptoms

3. Scratching can lead to:

   • Secondary bacterial infection
   • Scarring
   • Prolonged healing time
   • Increased risk of post-herpetic neuralgia

4. Cooling, not heating - Heat can increase blood flow and worsen itching, while cooling provides relief

By combining appropriate antiviral therapy with targeted symptomatic treatments for itching, most patients will experience significant relief while the infection resolves.