Herpes zoster (shingles) is a painful rash caused by the same virus that causes chickenpox. After an episode of chickenpox, the virus resides in cells of the nervous system. The term "shingles" comes from a Latin word, "cingulum", which means belt or girdle; the rash of herpes zoster usually appears in a band or beltlike pattern.
Shingles can affect people of all ages. It is particularly common in adults over age 50 years. It is also more common in individuals of all ages with conditions that weaken the immune system.
Shingles is caused by the varicella-zoster virus, the same virus that causes chickenpox. After an episode of chickenpox, the virus retreats to cells of the nervous system, where it can reside quietly for decades. However, later in life, the varicella-zoster virus can become active again. When it reactivates, it causes shingles.
The virus belongs to a group of viruses called herpesviruses, which also includes the herpes simplex virus (HSV); HSV-1 causes cold sores and HSV-2 causes genital herpes. (See "Patient information: Genital herpes (Beyond the Basics)".)
RISK OF SHINGLES
Up to 20 percent of people will develop shingles during their lifetime. The condition only occurs in people who have had chickenpox, although occasionally, chickenpox is mild enough that you may not be aware that you were infected in the past.
Age — Shingles can occur in individuals of all ages, but it is much more common in adults aged 50 years and older.
Immune status — Shingles can occur in healthy adults. However, some people are at a higher risk of developing shingles because of a weakened immune system. The immune system may be weakened by:
- Certain cancers or other diseases that interfere with a normal immune response
- Immune-suppressing medications used to treat certain conditions (eg, rheumatoid arthritis) or to prevent rejection after organ transplantation
- Chemotherapy for cancer
- Infection with the human immunodeficiency virus (HIV), the virus that causes AIDS
SHINGLES SIGNS AND SYMPTOMS
Shingles usually begins with unusual sensations, called parasthesias, such as itching, burning, or tingling in an area of skin on one side of the body. Some people develop a fever, a generalized feeling of being unwell, or a headache. Within one to two days, a rash of blisters appears on one side of the body in a bandlike pattern (picture 1A-B).
The trunk (chest, upper, or lower back) is usually affected by the shingles rash (figure 1). The rash can also occur on the face; a rash appearing near the eye can permanently affect vision (see 'Eye complications' below).
The pain of shingles can be mild or severe, and usually has a sharp, stabbing, or burning quality. Pain may begin several days before the rash. Pain is limited to the skin affected by the rash, but it can be severe enough to interfere with daily activities and sleep. Pain is often worse in older adults compared to younger individuals.
Within three to four days, the shingles blisters can become open sores or "ulcers". These ulcers can sometimes become infected with bacteria. In individuals with a healthy immune system, the sores crust over and are no longer infectious by day 7 to 10, and the rash generally disappears within three to four weeks. Scarring and changes in skin color may persist long after shingles has resolved.
In most individuals, shingles runs its course without any lasting health problems. However, the condition can be associated with complications.
Is shingles contagious? — It is not possible to catch shingles from another person. However, some people can become infected with the varicella-zoster virus itself:
- If you have never had chickenpox or the chickenpox vaccine, you can develop chickenpox after direct (skin to skin) contact with a shingles blister or by inhaling the varicella-zoster virus in the air. You should take precautions if you are near anyone with shingles. (See "Patient information: Chickenpox prevention and treatment (Beyond the Basics)".)
- If you have had chickenpox or the chickenpox vaccine, being near a person with shingles will not cause you to develop shingles.
Complications of shingles can occur in anyone with the condition, but are more likely in older adults and in those with a weakened immune system. Overall, complications occur in about 12 percent of all individuals with shingles.
Pain — Postherpetic neuralgia (PHN) is the most common complication of shingles. It causes mild to severe pain or unpleasant sensations and is often described as "burning". PHN affects 10 to 15 percent of patients, with about half of these cases in individuals older than 60 years.
In most patients, the pain of postherpetic neuralgia gradually improves over time. Some patients continue to experience pain for months to years after the rash resolves. This pain can be so severe that it causes difficulty sleeping, weight loss, depression, and interferes with normal daily activities. Several treatments are available to both prevent and treat PHN. (See 'Treatment of postherpetic neuralgia' below.)
Skin infection — The sores of shingles can become infected with bacteria, and this can delay healing. This complication occurs in about 2 percent of individuals. (See "Patient information: Skin and soft tissue infection (cellulitis) (Beyond the Basics)".)
Eye complications — Eye complications occur in about 2 percent of individuals. Eye complications are much more likely to occur when the shingles rash occurs around the eye. These complications are serious and can lead to vision loss.
Eye inflammation — Eye inflammation (called herpes zoster ophthalmicus) typically begins with fever, headache, decreased vision, a droopy eyelid, and a generalized feeling of being unwell. These symptoms are accompanied by pain or extreme sensitivity of the eye, forehead, and top of the head.
Early diagnosis and treatment are important in preventing worsening eye inflammation and vision loss. People who have zoster lesions near an eye should be evaluated immediately by an eye specialist. Treatment usually includes oral acyclovir, valacyclovir, or famciclovir plus steroid eye drops to reduce inflammation.
Retinal inflammation — Herpes zoster of the eye can cause inflammation and damage of the retina (called acute retinal necrosis). The retina is in the back of the eye, and is the part of the eye that senses light and enables vision. Retinal inflammation can progress rapidly in individuals with HIV infection.
Retinal inflammation usually begins with blurry vision and pain in one eye. In up to 50 percent of individuals, it later affects the other eye. It is treated with intravenous acyclovir, which improves symptoms within 48 to 72 hours.
Ear inflammation — Herpes zoster can cause inflammation of the ear (called herpes zoster oticus or Ramsay Hunt syndrome). Symptoms include weakness of the facial muscles on the affected side. (See "Clinical manifestations of varicella-zoster virus infection: Herpes zoster".)
Complications due to immune suppression — People with a weakened immune system, including people infected with HIV and transplant recipients, are at substantial risk for severe varicella zoster virus related complications.
Treatment of shingles usually includes a combination of antiviral and pain-relieving medications. The affected areas should be kept clean and dry. Creams or gels might increase the likelihood of a secondary bacterial skin infection and are not recommended.
Antiviral medications — Antiviral medications stop the varicella zoster virus from multiplying, speed healing of skin lesions, and reduce the severity and duration of pain.
Antiviral treatment is recommended for EVERYONE with shingles, and is most effective when started within 72 hours after the shingles rash appears. After this time, antiviral medications may still be helpful if new blisters are appearing.
Three antiviral drugs are used to treat shingles: acyclovir (Zovirax®), famciclovir (Famvir®), and valacyclovir (Valtrex®). Acyclovir is the least expensive treatment but it must be taken more frequently than the other drugs.
Pain medications — The pain of shingles and postherpetic neuralgia can be severe, and prescription medications are frequently needed.
Treatment of postherpetic neuralgia — Treatment is available to reduce pain and maintain quality of life in people with postherpetic neuralgia. Treatment generally begins with a low-dose tricyclic antidepressant, and may also include narcotic medications and an anti-seizure medication.
Tricyclic antidepressants — Tricyclic antidepressants (TCAs) are commonly used to treat the pain of postherpetic neuralgia. The dose of TCAs is typically much lower than that used for treating depression. It is believed that these drugs reduce pain when used in low doses, but it is not clear how the drug works.
TCAs used to treat pain include amitriptyline, desipramine, and nortriptyline. It is common to feel tired when starting a tricyclic antidepressant; this is not always an undesirable side effect since it can help improve sleep when TCAs are taken in the evening. TCAs are generally started in low doses and increased gradually. The pain-relief benefit may not be seen for three or more weeks. Tricyclic antidepressants may not be recommended for older adults with heart problems.
Oral pain medications — Prescription pain medications may be recommended if tricyclic antidepressants do not provide enough pain relief.
Anti-seizure medications — Medications that are traditionally used to prevent seizures, called anticonvulsants, can sometimes reduce the pain of postherpetic neuralgia. They may be used instead of or in addition to TCAs. Anticonvulsants commonly used for postherpetic neuralgia include gabapentin (Neurontin®) and pregabalin (Lyrica®).
Capsaicin — Capsaicin is a substance derived from chili peppers that can help to treat pain. Capsaicin cream (Zostrix®) may be recommended to treat postherpetic neuralgia. However, the side effects of the cream (including burning, stinging, and skin redness) are intolerable for up to one-third of patients.
Topical anesthetics — Lidocaine (Xylocaine) gel is a medicine that you can rub into your skin. A lidocaine patch (Lidoderm®) is also available, which you wear on your skin for 12 hours per day. It delivers a small amount of lidocaine to the most painful or itchy areas. However, the benefit of lidocaine is likely to be moderate at best.
Steroid injections — For people with postherpetic neuralgia who have severe pain despite using the above measures, an injection of steroids directly into the space around the spinal cord may be considered. Steroid injections are not used to treat facial pain.
In one study of patients with postherpetic neuralgia for at least one year, steroid injections led to good or excellent pain relief in about 90 percent of individuals .
RETURN TO WORK
If you have shingles, you may wonder when it is safe to return to work. The answer depends upon where you work and where your blisters are located.
- If the blisters are on your face, do not return to work until the area has crusted over, which generally takes seven to 10 days.
- If the blisters are in an area that you can cover (eg, with a gauze bandage or clothing), you may return to work when you feel well.
- If you work in a healthcare facility (hospital, medical office, nursing home), consult your healthcare provider about when it is safe to return to work.
PREVENTION OF SHINGLES
Vaccination — A vaccine is now available to reduce the chance of developing shingles. If you do develop shingles after receiving the vaccine, your infection may be less severe and you are less likely to develop postherpetic neuralgia .
The vaccine is recommended for most adults over 60 years. You should get the vaccine even if you are not sure if you had chicken pox or shingles previously. The vaccine is not recommended for people with a weakened immune system, pregnant women, or those with a history of a severe allergic reaction to gelatin or neomycin.
Natural boost of immunity — If you have had chickenpox previously, you have developed immunity to the virus that causes shingles. However, this immunity declines over time. But, if you are later exposed to a child or adult with chickenpox, your immunity to the virus is "boosted". This boost may help to reduce your risk of developing shingles.
WHERE TO GET MORE INFORMATION
Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
Patient information: Chickenpox (The Basics)
Patient information: Shingles (The Basics)
Patient information: Neuropathic pain (The Basics)
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient information: Genital herpes (Beyond the Basics)
Patient information: Chickenpox prevention and treatment (Beyond the Basics)
Patient information: Skin and soft tissue infection (cellulitis) (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Clinical manifestations of varicella-zoster virus infection: Herpes zoster
Diagnosis of varicella-zoster virus infection
Epidemiology and pathogenesis of varicella-zoster virus infection: Herpes zoster
Prevention of varicella-zoster virus infection: Herpes zoster
Treatment of herpes zoster in the immunocompetent host
Varicella-zoster virus infection in pregnancy
The following organizations also provide reliable health information.
- National Library of Medicine
(www.nlm.nih.gov/medlineplus/shingles.html, available in Spanish)
- Centers for Disease Control and Prevention (CDC)
Phone: (800) 311-3435
- National Institute of Neurological Disorders and Stroke