Treatment of Chronic Herpes Zoster (Postherpetic Neuralgia)
Primary treatments for postherpetic neuralgia include neuroactive agents, such as tricyclic antidepressants; anticonvulsant agents, such as gabapentin and pregabalin; and narcotic and non-narcotic analgesics, both systemic, such as opioids, and topical, such as capsaicin. No standard treatment plans or protocols exist for treating the pain associated with postherpetic neuralgia. Consultation with pain specialists may be required.
Placebo-controlled trials of various antiviral agents in treating herpes zoster have shown clear reductions in the intensity and duration of acute zoster-associated pain among treated populations. However, whether the use of antivirals in acute zoster reduces the incidence or duration of postherpetic neuralgia is less clear. Meta-analyses and studies have given conflicting results, and the subject is still under debate in the literature. Treating established postherpetic neuralgia with antivirals has not been shown to be beneficial.
The use of oral or epidural corticosteroids in conjunction with antiviral therapy has been found to be beneficial in treating moderate-to-severe acute zoster, but to have no effect on the development or duration of postherpetic neuralgia.
Intrathecal administration of corticosteroids has also been attempted. A trial involving a series of 4 intrathecal injections of methylprednisolone and lidocaine in patients with established postherpetic neuralgia demonstrated a significant and persistent reduction in pain among corticosteroid-treated patients when compared with untreated patients or those treated with intrathecal lidocaine alone. However, as these results have not received independent confirmation, and there are significant safety concerns with administration of intrathecal steroids, this treatment modality is not recommended.
