Which topical therapy is used for postherpetic neuralgia?

Which topical therapy is used for postherpetic neuralgia?

• A. Topical lidocaine gel or capsaicin
• B. Hydrocortisone cream
• C. Mupirocin ointment
• D. Aloe vera gel

Answer: (A)

Postherpetic neuralgia is persistent neuropathic pain after a shingles outbreak, and targeted topical therapies can provide relief by acting directly on peripheral nerves. The best option among topical agents for this condition is a topical local anesthetic or a capsaicin preparation. Topical lidocaine works by blocking voltage-gated sodium channels on damaged nerves, which dampens abnormal nerve firing and reduces pain signals from the affected area with minimal systemic effects. Capsaicin, on the other hand, activates TRPV1 receptors on nociceptive fibers, causing an initial burning sensation followed by depletion and desensitization of substance P and other neuropeptides. This leads to decreased transmission of pain signals over time. Both approaches are applied locally to the involved dermatomes and are specifically useful for neuropathic pain like PHN. Other choices don’t target the nerve pain mechanism in PHN: hydrocortisone cream is a steroid that reduces inflammation but doesn’t address neuropathic pain; mupirocin is an antibiotic for skin infections; aloe vera is soothing for irritation but lacks evidence for treating PHN.

Postherpetic neuralgia is persistent neuropathic pain after a shingles outbreak, and targeted topical therapies can provide relief by acting directly on peripheral nerves. The best option among topical agents for this condition is a topical local anesthetic or a capsaicin preparation.

Topical lidocaine works by blocking voltage-gated sodium channels on damaged nerves, which dampens abnormal nerve firing and reduces pain signals from the affected area with minimal systemic effects. Capsaicin, on the other hand, activates TRPV1 receptors on nociceptive fibers, causing an initial burning sensation followed by depletion and desensitization of substance P and other neuropeptides. This leads to decreased transmission of pain signals over time. Both approaches are applied locally to the involved dermatomes and are specifically useful for neuropathic pain like PHN.

Other choices don’t target the nerve pain mechanism in PHN: hydrocortisone cream is a steroid that reduces inflammation but doesn’t address neuropathic pain; mupirocin is an antibiotic for skin infections; aloe vera is soothing for irritation but lacks evidence for treating PHN.