Presented by RW Johnson. Bristol Royal Infirmary, Bristol, UK.

The majority of patients developing shingles will suffer no more than a few days of inconvenience and discomfort. A very significant minority however, particularly the elderly, will experience the start of a prolonged period, sometimes lifelong, of misery. All diseases have biological, psychological and social influences and the pain following herpes zoster (HZ), postherpetic neuralgia (PHN), is no exception. Although a definition for PHN is now almost universally accepted (significant pain or painful abnormal sensation 120 or more days after HZ rash appearance), the precise causative pathology varies between individuals as does the detail of the symptoms.

Ideally management of a neuropathic pain such as PHN should be both mechanism based and evidence based. Despite significant advances in the understanding of mechanisms for PHN, treatment remains somewhat empirical. There have also been advances in the development of pharmacological tools for neuropathic pain management but few have been satisfactorily tested for more than short term administration. Efficacy of combination therapy has hardly been investigated at all.

Current knowledge indicates that established PHN may respond to tricyclic antidepressants (e.g. amitriptyline, nortriptyline), alpha-2-delta ligands (e.g.gabapentin, pregabalin) and opiates (e.g. morphine, oxycodone) with similar frequency. However, an individual with PHN may respond to one treatment but not others. Combination therapy, particularly of an alpha-2-delta ligand and an opiate, may be synergistic allowing greater benefit with reduced doses of both classes of drug and reduction of side effects. Adjunctive therapy with topical agents such as lidocaine may provide significant additional benefit. The results of a recent Systematic Review of PHN therapy will be presented.

To provide optimal management, thorough assessment, painstaking advice and surveillance with willingness to pursue pain alleviation over time, are necessary. Despite perseverance, some PHN patients will not gain satisfactory relief and Cognitive Pain Management Programmes may be considered. For HZ patients with significant risk factors for PHN (greater age, severe acute pain and/or rash or prodromal pain), it may be that prophylactic administration of an alpha-2- delta ligand and opiate may afford protection although this has still to be convincingly demonstrated in humans. Antiviral drugs, particularly those with good bioavailability (famciclovir, valaciclovir, brivudin) remain an important preventive therapy reducing the incidence of PHN by approximately 50%.

Widespread adoption of child varicella vaccination programmes will ultimately eradicate varicella although paradoxically they may increase its incidence in the short and medium terms. After a generation or so, the pool of adults carrying latent VZ virus will be deceased and HZ will also be eradicated. In the meantime, preventive strategies for PHN should be strongly encouraged and the search for more effective therapy of established PHN should continue.

Presentation not available online