Postherpetic neuralgia (PHN) is the most common complication of herpes zoster. PHN is a neuropathic pain that is usually severe, with a significant impact on the daily functioning of patients, especially elderly patients whose independence can be threatened. PHN is difficult to treat, and in most patients a combination of systemic, local, interventional, behavioural and physical management will be required.
- Postherpetic neuralgia (PHN) is a late complication of herpes zoster.
- Clinically, pain persisting after the resolution of the herpes zoster rash should be regarded as PHN.
- Because of the complicated and varied pathogenesis of PHN, determining the best therapeutic approach is problematic.
- Risk factors for developing PHN include severe acute pain during herpes zoster, severe rash, ophthalmic involvement, increasing age and diabetes.
- Vaccination with live-attenuated varicella–zoster virus and actively managing the pain of herpes zoster reduce the risk of PHN.
- A combination of first-, second-and possibly third-line medication options is often required to obtain the desired response in patients with neuropathic pain.
- Systemic treatments for PHN include tricyclic antidepressants, pregabalin and gabapentin as first-line options, and serotonin and noradrenaline reuptake inhibitors and opioids as second-line options.
- Lignocaine 5% skin patches are efficacious on areas where patients have allodynia.
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