Shingles is a painful infection of the nerves and skin caused by the varicella zoster virus. This is the same virus that causes chickenpox.
Causes
Shingles occurs in people who have already had chickenpox. It is considered a reactivation of the dormant varicella zoster virus. After causing the initial chickenpox infection, the virus does not leave the body. Instead, it settles in the nerve roots near the spinal cord. Once reactivated, the virus travels along the nerve paths to the skin. There it produces the pain and rash.
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
Most cases of shingles occur in individuals with no known risk factor other than age.
Shingles cannot be transmitted from one person to another. However, contact with a person who has shingles could lead to chickenpox in someone who has never had chickenpox and has not received the varicella vaccine.
Symptoms
Symptoms include:
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Rash:
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In severe cases, the eyes may be affected, which can seriously threaten vision.
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Pain on the skin at the site of the rash, which is usually severe
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Tingling or itchiness on the skin, which may start a few days before the rash
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Skin in the affected area is unusually sensitive to touch
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Fever
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Headache
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Tiredness
The rash usually disappears within three weeks, but the pain may linger. In some patients, however, the pain continues long after the rash has healed. This complication is called post-herpetic neuralgia (PHN). It refers to pain that is present in the affected area for months, or even years afterward. The pain of PHN is difficult to treat and can be very severe.
Diagnosis
The doctor will ask about your symptoms and medical history, and perform a physical exam. Usually the rash can be diagnosed by its appearance. Rarely, drawing fluid from the blisters and sending it to a lab is necessary to confirm the diagnosis.
Treatment
Like any viral condition, shingles cannot be cured. Treatment, therefore, is focused on alleviating symptoms, speeding recovery, and preventing PHN.
Itch and Pain Relief
Itching may be relieved by:
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Calamine lotion
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Wet compresses
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Frequent oatmeal baths
Over-the-counter pain relievers include:
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Oral medications like acetaminophen (Tylenol), ibuprofen (Advil), and naproxen (Aleve)
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Capsaicin, a substance originally derived from hot peppers, applied topically as an ointment
Prescription drugs may be given to help relieve pain that doesn't respond to over-the-counter remedies.
Antiviral Drugs
Certain antiviral medications may help control shingles by hindering reproduction of the virus in the nerve cells. They include:
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Acyclovir (Zovirax)
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Famciclovir (Famvir)
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Valacyclovir (Valtrex)
Antiviral therapy may shorten the course of an episode of shingles, but only if started within 48-72 hours after symptoms first develop. These medications can also reduce the severity and duration of PHN and are generally recommended in patients at highest risk for this condition (ie, over 55).
Steroids
A short course of oral steroid medication (eg, prednisone) may also be prescribed in patients whose immune system is functioning normally.
Post-herpetic Neuralgia
Taking antiviral medications before PHN develops is the most effective way to reduce its severity.
A variety of other treatments are available to help as well:
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Capsaicin topical ointment may also be useful for PHN
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Tricyclic antidepressants are typically prescribed in doses lower than those needed to treat depression. An SSRI (selective serotonin reuptake inhibitor) may also be prescribed.
Lidoderm Patch–a transdermal form of lidocaine (a local anesthetic), in which the medication is gradually absorbed across the skin
Gabapentin–an anti-seizure medication also useful in the treatment of PHN
Transcutaneous Electrical Nerve Stimulation (TENS)–a device that generates low-level pulses of electrical current and applies it to the skin's surface
Nerve Blocks–these are injections near nerves that may be used to provide temporary pain relief (usually used as a last resort)
Prevention
There is no proven way to prevent an outbreak of shingles, although avoiding undue stress and fatigue may possibly help prevent an outbreak. Future cases of shingles should theoretically diminish as more children avoid chickenpox by receiving the varicella vaccine.
The US Food and Drug Administration recently approved a vaccine (Zostavax) for people over 60 who have had chickenpox, to help decrease the likelihood of getting shingles and to decrease severity if shingles does occur.
RESOURCES:
National Institute of Neurological Disorders and Stroke
http://www.ninds.nih.gov
VZV Research Foundation (for research on Varicella Zoster)
http://www.vzvfoundation.org
References:
Management of herpes zoster and postherpetic neuralgia. Am Fam Physician. 2000 Apr 15.
The Merck Manual of Geriatrics (on-line edition). Merck and Co.; 2000.
Shingles: an unwelcome encore. FDA Consumer Magazine. 2001 May-June.
