[Prevention of postherpetic neuralgia: does it exist?]

Area of Science:

• Neurology
• Pain Management
• Virology

Context:

• Postherpetic neuralgia (PHN) is a chronic pain condition following herpes zoster (shingles).
• Pathophysiological mechanisms include peripheral and central sensitization, and neuronal degeneration with aberrant sprouting.
• Potential preventive strategies target pain control in the acute phase and reducing neuronal damage.

Purpose:

• To review the evidence for interventions aimed at preventing postherpetic neuralgia.
• To evaluate the efficacy of antiviral drugs, corticosteroids, neurotrophins, and antidepressants in PHN prevention.
• To assess the role of adequate analgesia during acute herpes zoster.

Summary:

• Clinical trials on PHN prevention primarily focused on antiviral drugs; acyclovir reduced acute pain and healing time but not PHN incidence.
• Second-generation antivirals (valaciclovir, famciclovir) and early-onset amitriptyline may reduce PHN, but require further confirmation.
• No intervention definitively prevents PHN, but comprehensive analgesia during acute herpes zoster is strongly recommended.

Impact:

• Highlights the importance of managing acute herpes zoster pain to mitigate long-term neuropathic pain.
• Identifies areas for future research in PHN prevention, particularly regarding early intervention with specific drug classes.
• Informs clinical practice by emphasizing the current best approach for PHN prevention.