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From Citizendium, the Citizens' Compendium

Herpes zoster is "an acute infectious, usually self-limited, disease believed to represent activation of latent varicella-zoster virus in those who have been rendered partially immune after a previous attack of Chickenpox. It involves the sensory ganglia and their areas of innervation and is characterized by severe neuralgic pain along the distribution of the affected nerve and crops of clustered vesicles over the area."^[1]

Contents 1 Epidemiology 2 Prevention 3 Treatment 4 References

Epidemiology

For adults over 60 years of age, the incidence is about 1% per year.^[2]

Prevention

The Centers for Disease Control recommends the zoster vaccination (Zostavax - which is different than the pediatric vaccine Variva) for adults aged at least 60 years:^[3] Contraindications include:^[4]

• allergic to neomycin, or any component of the vaccine
• immuncompromise due to radiation, corticosteroids, or conditions such as AIDS and cancers.
• pregnancy
• people who are in close contact with pregnant women who have not had chickenpox probably not have vaccine

A randomized controlled trial of a vaccine for adults aged at least 60 years reduced the incidence of zoster over three years by about one-half - from a rate of 3.3% down to 1.6%; approximately 60 people would have to take the vaccine to prevent one case of shingles (number needed to treat=59).^[5]

Treatment

While the acute phase is uncomfortable, the greatest concern is that some patients, not treated aggressively, may develop a severe chronic pain syndrome called postherpetic neuralgia (PHN). Since there are safe and effective antiviral agents, they are the first step: acyclovir, famciclovir, and valacyclovir. Combining these with a corticosteroid is more effective than antiviral therapy alone, for outcomes of are acute pain, function, and quality of life. Antivirals will not prevent PHN.^[6]

If postherpetic neuralgia develops, there are a number of therapies, which need to be individualized:

• lidocaine patches applied to the skin
• capsaicin cream applied frequenly to the skin
• tricyclic antidepressants (TCAs), especially desipramine
• anticonvulsants such as gabapentin and pregabalin
• opioid analgesics

While the anticonvulsants had been considered highly effective, a study showed that desipramine was consistently more effective. ^[7]

References

1. ↑ National Library of Medicine. Herpes Zoster. Retrieved on 2007-11-02.
2. ↑ Yawn BP, Saddier P, Wollan PC, St Sauver JL, Kurland MJ, Sy LS (2007). "A population-based study of the incidence and complication rates of herpes zoster before zoster vaccine introduction". Mayo Clin. Proc. 82 (11): 1341–9. PMID 17976353.
3. ↑ Centers for Disease Control and Prevention (2006). CDC Media Relations Press Release - October 26, 2006. Retrieved on 2007-10-22.
4. ↑ Centers for Disease Control and Prevention (2006). CBER - Zoster Vaccine, Live, (Oka/Merck), Zostavax Questions & Answers. Retrieved on 2007-10-22.
5. ↑ Oxman MN, Levin MJ, Johnson GR, et al (2005). "A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults". N. Engl. J. Med. 352 (22): 2271–84. DOI:10.1056/NEJMoa051016. PMID 15930418.
6. ↑ High, Kevin (30 September 2005), "Reducing the Public Health Burden of Herpes Zoster and Postherpetic Neuralgia", Medscape CME
7. ↑ O'Connor AB, Noyes K, Holloway RG (2007), "A Cost-Effectiveness Comparison of Desipramine, Gabapentin, and Pregabalin for Treating Postherpetic Neuralgia", Journal of the American Geriatrics Society 55 (8) pp. 1176-1184