Post-herpetic neuralgia is a neuropathic pain syndrome that is notoriously difficult to manage. It is preceded by an acute attack of herpes zoster (shingles) and usually occurs at the site of shingles skin lesions. While acute herpetic pain occurs before and during the presence of the shingles rash, post-herpetic neuralgia is pain that continues beyond the normal healing time of the rash.
Post-herpetic neuralgia has been variously defined as pain persisting, or recurring, beyond one, three and six months after the onset of the rash. Since many cases resolve spontaneously in the first few months, it seems reasonable to assume a diagnosis of post-herpetic neuralgia if the pain continues beyond three months after the acute rash (Dworkin and Portenoy, 1996).
The reported incidence of post-herpetic neuralgia depends on the definition used. National data suggest that there are 25,000 new cases in the UK each year, and an annual prevalence approaching 50,000 (Bowsher, 1997).
The condition is frequently underdiagnosed (Padfield, 1997), despite being consequent to having had shingles. Management is difficult with traditional analgesics because the shingles virus can cause so much nerve damage in the few days before a patient seeks medical help. Specific analgesic regimens for relieving nerve pain, therefore, are required.
In total, 10-25 per cent of patients who have pain one month post-shingles will have pain one year later (Ragozzino et al, 1982; Fig 1). This is likely have a devastating impact on their quality of life. Health care practitioners have a duty to help people obtain both a swift diagnosis and offer early, appropriate treatment.