What are the recommendations for managing pain associated with herpes infections using topical painkillers?

Management of Herpes-Associated Pain with Topical Painkillers

Lidocaine patches (5%) are recommended as first-line topical treatment for pain associated with herpes infections due to their proven efficacy and favorable safety profile. 1, 2

First-Line Topical Treatments

• Lidocaine patches (5%) provide significant pain relief for herpes-related pain by blocking sodium ion channels required for the initiation and conduction of neuronal impulses 1, 2
• Lidocaine patches can be applied to the affected areas for 12-24 hours and are particularly practical for use on larger surfaces 1
• Lidocaine patches deliver the medication gradually over hours, making them more effective than lidocaine creams or ointments 1
• For acute herpes zoster, lidocaine patches applied twice daily have demonstrated effectiveness in relieving moderate to severe pain with minimal side effects 2

Alternative Topical Options

• Capsaicin (8% dermal patch or cream) is recommended for management of chronic herpes-associated peripheral neuropathic pain 1

  • A single 30-minute application can provide pain relief for up to 12 weeks 1
  • Common side effects include erythema and pain, which can be managed by applying 4% lidocaine for 60 minutes before capsaicin application 1

• Amitriptyline-ketamine topical combination can be applied to affected areas up to 3 times daily to help control herpes-related pain 1

  • This combination works through multiple mechanisms: amitriptyline inhibits serotonin and norepinephrine re-uptake and blocks sodium channels, while ketamine acts as an N-methyl-D-aspartate receptor antagonist 1

Treatment Considerations for Post-Herpetic Neuralgia

• For post-herpetic neuralgia (PHN), topical lidocaine patches have shown excellent analgesic efficacy with a number needed to treat (NNT) of 2 1
• Topical capsaicin 0.075% is also effective for PHN with an NNT of 3.26 1
• For patients with inadequate response to topical treatments, systemic medications may be considered:
  • Gabapentin is recommended as first-line oral treatment 1
  • Pregabalin may be considered if patients have an inadequate response to gabapentin 1
  • Tricyclic antidepressants (amitriptyline, nortriptyline, desipramine) are additional options 1, 3

Application Guidelines

• For lidocaine patches:

  • Apply to intact skin (avoid open lesions) 2
  • Can be worn for 12-24 hours per day 1
  • Up to 3 patches may be used simultaneously for larger areas 1

• For lidocaine gel:

  • Apply to intact skin surrounding the lesions 4
  • May be used with or without occlusive dressing 4
  • Apply at 12-hour intervals 2

Important Caveats

• Topical treatments should be applied to intact skin, avoiding open lesions or blisters 2
• Topical antivirals are not effective for prophylaxis as they cannot reach the site of viral reactivation 1
• Patients with severe, frequent, or complicated disease may require systemic antiviral therapy in addition to topical pain management 1
• For acute herpes zoster, early initiation of treatment (within 72 hours of onset) is crucial for reducing pain intensity and duration 3
• Topical lidocaine has minimal systemic absorption when used as directed, making it a safe option for most patients 2, 5