Shingles

Shingles (zoster or herpes zoster) is a frequently painful outbreak of rash or blisters on the skin that is caused by the same virus that causes chickenpox (varicella) — the varicella-zoster virus. Anyone who has had chickenpox is at risk for shingles.

A shingles rash, showing the typical appearance and tendency to stick to a single dermatome. Source: Wikimedia Commons

About 20% of the population gets shingles in their lifetime.^[1]

Other Names

• Zoster
• Herpes Zoster

Symptoms

The first symptom of shingles is often burning or tingling pain, or sometimes numbness or itch, in one particular location on only one side of the body. After several days or a week, a rash of fluid-filled blisters, similar to chickenpox, appears in one area on one side of the body. They do not cross the midline. Shingles pain can be mild or intense. Some people have mostly itching; some feel pain from the gentlest touch or breeze. In about 20% of people, the rash is accompanied by other symptoms like headache and fever.

The most common location for shingles is a band, called a dermatome, spanning one side of the trunk around the waistline. The thorax is most common, followed by the lower back.

The blisters may look different depending on their stage, ranging from red bumps to clear blisters to pus-filled blisters to scabs. Sometimes they're described as looking like "dewdrops on a rose petal", for their clear-on-red appearance.

Sometimes blisters occur on the tip of the nose; this is a warning sign of possible eye involvement, because the nose and eye share a nerve called the nasociliary nerve. The doctor should check the cornea of the eye. Swollen lymph nodes and facial nerve problems such as Bell's palsy may develop in some cases of shingles.

The rash generally lasts 7-10 days, then begins to crust over. Sometimes scars are left after healing. The pain of shingles, which is characteristically intense and activated by light touch or even clothing touching the area (hyperacusis), may continue for a long time afterwards and often needs medical treatment. The pain is related to ongoing sensitivity of the nerves from which the virus erupted. This is called post-herpetic neuralgia.

Causes

Drawing by Renee Gordon. Source: Wikimedia Commons, http://www.fda.gov.

Shingles is a reactivation of the varicella zoster (chickenpox) virus. Once a person gets chickenpox, the virus stays in their body for life, lying dormant in nerve roots near the spine.

When the varicella-zoster virus reactivates, the virus moves back down the long nerve fibers that extend from the sensory cell bodies to the skin. The viruses multiply, the tell-tale rash erupts, and the person now has shingles.

What causes reactivation of the virus is still unclear, but we do know that a part of the immune system called cell-mediated immunity is involved, because people with impairments of that type of immunity are more susceptible to shingles.

You cannot catch shingles, but the shingles lesions can spread chickenpox. A person with a shingles rash can pass the virus to someone, usually a child, who has never had chickenpox, but the child will develop chickenpox, not shingles. For this reason people with shingles are usually advised to avoid pregnant women, elderly people and people with poor immune systems, for example people undergoing chemotherapy treatment for cancer or immunosuppressants for kidney transplants.

On the other hand, a person with chickenpox cannot communicate shingles to someone else. Shingles comes from the virus hiding inside the person's body, not from an outside source.

Shingles appears to become more common with age. It is fairly common in the elderly and very uncommon in adolescents and children.

Diagnosis

Shingles is usually diagnosed by history and a physical examination; tests are not needed. The rash is almost always on only one side of the body, distributed along a specific patch of skin (a dermatome); the fluid-filled blisters are painful; and the person can often remember having had chickenpox in the past.

When the person feels pain along a dermatome in the days preceding the rash, this pain can be mistaken for kidney stones, heart pain (angina) or pain inside the belly. Once the rash breaks out the diagnosis is more obvious.

Occasionally a blister is swabbed to detect virus and make certain of the diagnosis. Blood tests are rarely performed.

Treatment

Antiviral drugs can be used to reduce the severity and the duration of an attack. These include acyclovir, valcyclovir, or famcyclovir. They need to be taken within two or three days of the beginning of the rash to have the most chance of being effective. Antiviral drugs may also help stave off the painful after-effects of shingles known as postherpetic neuralgia. Acyclovir has typically been the treatment of choice, though the regimen of taking the drug five times a day is difficult for patients. In hospitalised patients with shingles, intravenous acyclovir is often used. This is the treatment of choice for multi-dermatomal shingles, disseminated shingles, shingles in patients with immunosuppression, and shingles affecting the eye.

Treatments for the pain of shingles include oral medications, such as acetominophen (Tylenol) or ibuprofen (Advil); medicated lotions like Benadryl; or astringent lotions like Bluboro.

Treatments for postherpetic neuralgia include steroids, tricyclic antidepressants such as amitryptiline (in low doses for their pain-relief effect), anticonvulsants (for their pain-relief effect), and topical pain-relief agents like lidocaine, although lidocaine's effectiveness is unclear.^[2] Sometimes opioids like codeine are necessary to control the pain.

Prevention

A safe and effective vaccine against varicella-zoster virus has been available since 1995. It is recommended that children receive it between 12 and 18 months of age.^[3] This vaccine protects children from getting the chickenpox that would have led to zoster. Its effectiveness has been dramatic, with a huge decline in the number of reported cases of chickenpox since 1995.^[4]

In 2006, the Food and Drug Administration approved a more potent version of the varicella-zoster virus vaccine for use in people 60 and older who have had chickenpox. Researchers found that giving older adults the vaccine reduced the expected number of later cases of shingles by half. And in people who still got the disease despite immunization, the severity and complications of shingles were dramatically reduced. The shingles vaccine is only a preventive therapy and is not a treatment for those who already have shingles or postherpetic neuralgia.

Complications

The most common complication of herpes zoster is post-herpetic neuralgia, a pain that lasts more than a month after the rash has healed. Most cases occur in the elderly, and the risk of developing post-herpetic neuralgia is as high as 75% in people over the age of 70.^[5] In about 2% of people, this neuralgia can last for more than a year,^[6] though it usually resolves within a few months.

Other complications include:

• Bacterial infection of the rash
• Damage to the eye if the shingles involve the second branch of the trigeminal nerve of the face
• Facial weakness, hearing loss, and other nerve symptoms if the shingles involves certain nerves of the face. This is called Ramsay Hunt syndrome.
• Disseminated zoster: the rash spreads via the bloodstream to involve multiple dermatomes or internal organs. It is usually seen in patients with weakened immune systems, and can lead to organ damage or death.
• Meningoencephalitis: the virus infects the brain and lining of the spinal cord. This is more likely to happen in patients with weakened immune systems.

People with weakened immune systems, such as those with HIV^[7] or who are taking medications to suppress the immune system, can have worse zoster and more complications.

Prognosis

For most healthy people, the lesions heal, the pain subsides within three to five weeks, and the blisters leave no scars. However, shingles is a serious threat in immunosuppressed people — for example, those with HIV infection or who are receiving cancer treatments that can weaken their immune systems. People who receive organ transplants are also vulnerable to shingles and its complications because they are given drugs that suppress the immune system.

Clinical Trials

For clinical trials on shingles currently seeking patients, visit here

Research

The National Institute of Neurological Disorders and Stroke (NINDS) and other institutes of the National Institutes of Health (NIH) conduct shingles research in laboratories at the NIH and also support additional research through grants to major medical institutions across the country. Current research is aimed at finding new methods for treating shingles and its complications.

References

1. ↑ Whitley RJ. Varicella-zoster virus. In: Mandell GL, Bennett JE, Dolin R, editors. Principles and practice of infectious diseases, 4th ed. New York: Churchill Livingstone; 1995. p. 1345–51.
2. ↑ Khaliq W. Alam S. Puri N. Topical lidocaine for the treatment of postherpetic neuralgia. Cochrane Database of Systematic Reviews. (2):CD004846, 2007. Full Text
3. ↑ Hambleton S, Gershon AA. Preventing varicella-zoster disease. Clin Microbiol Rev. 2005 Jan;18(1):70-80. Abstract
4. ↑ Seward JF, Watson BM, Peterson CL, et al. 2002. Varicella disease after introduction of varicella vaccine in the United States, 1995-2000.] JAMA 287:606-611. Full Text
5. ↑ Ragozzino MW, Melton LJ, Kurland LT. Population-based study of herpes zoster and its sequelae. Medicine 1982;61:310-316. Abstract
6. ↑ Kurtzke JF. The current neurologic burden of illness and injury in the United States. Neurology 1982;32:1207-1214. Abstract
7. ↑ Vafai A. Berger M. Zoster in patients infected with HIV: a review. American Journal of the Medical Sciences. 2001 Jun; 321(6):372-80 Abstract

Links to Clinical Images

Zoster Shingles at Skinsight

Zoster Shingles at DermAtlas

Zoster Shingles at DermNetNZ

Zoster Shingles at Hardin MD

External Links

Mayo Clinic: Shingles

Family Doctor: Shingles

FDA, Shingles: An Unwelcome Encore