Prepared by Geoff Barnett, Freelance Medical Writer and Editor

It happened about 20 years ago. I\'d had this feeling of malaise for the best part of a week before I woke up one day with a tingling pain under my skin just above waist level, at the front on the right-hand side. Two days later a rash, about the size of my hand, appeared at the same site. The pain was worsening. I was becoming concerned. The bad news was that I was in Moscow; the good news was that I was nearing the end of my stay and, even better, there was a doctor in our party. The prodromal symptoms, the location of the erythema, and above all the characteristic appearance of clusters of clear, fluid-filled vesicles made her diagnosis straightforward - I had shingles. It ran an uneventful course, but it could have been worse, much worse...

Shingles, or herpes zoster, is caused by the varicella zoster virus (VZV), the same one that gives rise to chickenpox - a finding confirmed as late as the 1950s. Everyone who\'s had chickenpox - about nine out of ten adults - is at risk of developing shingles. In fact, only about 10-20% of us will contract the disease at some point in our lives, but it is more common in the elderly and those who are immunocompromised. VZV is a member of the herpes family of viruses, the Herpesviridae - indeed it is also known as human herpesvirus 3. Click on Human herpesvirus 3 (varicella-zoster virus 1) for a taxonomic description and to view an electron micrograph of virus particles. For a colourful, full-screen representation of the complex icosahedral capsid, click the link at the end of Structure and marvel that something so intricate measures about 100 nm (one nanometre is an unimaginable one thousand millionth of a metre).

Following recovery from chickenpox, VZV is not eliminated from the body but lies dormant in the roots of sensory nerves in the spinal cord or brain. Shingles represents a reactivation of the dormant VZV, and the associated pain and rash reflect the area supplied by the affected nerves. The areas, known as dermatomes, are shown diagrammatically at Varicella Zoster Virus and Dermatomes. The thorax is most commonly affected and classically a rash is seen encircling one half of the body (DOIA). It is this striking pattern that gives the disease its common name - the word \'shingles\' deriving from the Latin word cingulum, meaning belt or girdle. At this stage the virus has often induced significant inflammation of the involved sensory nerves, causing such severe pain that 19th century French physicians were led to refer to shingles as \'the band of roses from hell\'.

An outbreak of shingles may occur for no apparent reason, but probably results most often from a failure of the immune system to contain latent VZV replication. Predisposing factors may include advancing age, a weakened immune system, stress, certain cancers and physical injury. Normally, new lesions continue to appear for 2-3 days but eventually become haemorrhagic or turbid and crust over within 7-10 days (Grouped Crusts in a Zosteriform Distribution). After the crusts fall off, remaining erythematous plaques slowly resolve - scarring usually only occurring if deeper epidermal or dermal layers have been compromised.

Apart from the trunk, shingles can also attack other parts of the body. For example, herpes zoster ophthalmicus, herpes zoster of the eye, (Photo Gallery), second only to shingles of the torso in frequency, constitutes 10-15% of zoster cases and poses a risk to vision in the absence of prompt detection and treatment. Shingles affecting the ear (herpes zoster oticus or Ramsay Hunt syndrome) can be a particularly distressing condition. Intense ear pain is characteristic, and because facial nerves are affected, a rash typically appears around the face, neck and scalp, as well as the ear, with patients often exhibiting weakness of the muscles around the eye and mouth. A patient with an unusual case of Ramsay Hunt syndrome vividly recounts his experiences at Effects on Specific Body Areas.

Internationally, the incidence of zoster has not been well studied, but is probably similar to that in the US where it is estimated at 2-3 cases per 1000 per year (about 750,000 annually). Because many mild cases do not come to the attention of healthcare workers, the actual incidence may be significantly higher. Other statistics and fast facts can be found at After Shingles.

Many cases of shingles are mild and require little or no treatment, but where indicated there are three major objectives: treatment of the acute viral infection; treatment of the associated acute pain; and prevention, or reduction in the development of, postherpetic neuralgia (PHN), the most widely feared complication of shingles occurring in about 20% of patients. Until the introduction of antivirals the management of shingles had witnessed a vast number of therapeutic approaches, many of which were largely ineffective. But the discovery of aciclovir (Zovirax - GlaxoSmithKline) by Wellcome researchers and its subsequent launch in 1981 heralded a revolution in the treatment of herpetic diseases. Subsequent introductions of valaciclovir (Valtrex - Glaxo SmithKline) and famciclovir (Famvir - Novartis, acquired from SmithKline Beecham in 2000) have broadened the physician\'s prescribing options. Respective Websites are at Valtrex and Famvir. Click on Treating an Attack of Shingles with Anti-Viral Medications for a one-page summary comparing the use of the three drugs.

Other drugs used in the management of shingles include corticosteroids (to lessen pain by reducing inflammation in the affected nerves) and analgesics, ranging from over-the-counter medicines to narcotic analgesics, depending on the pain\'s severity. These and other treatments are discussed Management of Herpes Zoster (Shingles) and Postherpetic Neuralgia.

PHN is defined as pain persisting or recurring at the site of shingles 3 or more months after the appearance of the acute rash. One estimate indicates that in the UK about 200,000 people will be suffering from PHN at any one time, affecting about 50% of the over 65s who get shingles. The pain ranks high in the pain intensity league table, being one of the most agonising, and if untreated, persistent, pains known - so much so that it may render the patient\'s final years an unbearable misery. Treatment of Post-Herpetic Neuralgia in the Elderly, written by a consultant neurologist in the UK in the form of notes for doctors, provides a neat summary of the wide range of treatments used.

Currently, shingles cannot be prevented. However, a 5-year major study (The Shingles Prevention Study). is under way in the US to determine whether vaccination can decrease the incidence and/or severity of the disease and its complications. More than 35,000 people are being enrolled - all 60 years of age or older - who have had chickenpox but not shingles. Subjects will receive either 0.5 ml of freshly reconstituted live-attenuated varicella zoster vaccine or placebo. Globally the number of people in this age bracket (60+) is expected to double to 1.2 billion in 25 years time (A Tour around Aging), so the number of cases of shingles, PHN and other complications will inevitably rise, together with associated healthcare costs. But a successful outcome to the trial could have a significant and timely impact on this scenario and signal another victory in the fight against \'the band of roses from hell\'.

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