Shingles

What is shingles?

Shingles (herpes zoster) is a painful rash. It happens when the chickenpox virus, varicella zoster, becomes active again. After chickenpox, the virus remains inactive in nerve cells near the spinal cord and brain. Years later, it can reactivate and travel along a nerve to the skin, causing a band of painful blisters.

Who gets it?

About 1 in 5 people will have shingles at some point. Anyone who has had chickenpox can develop it. It becomes more common with age, particularly over the age of 50, and the risk rises further from 65 onwards, and is more common and can be more severe in people with a weakened immune system, for example due to HIV, cancer, or medicines that suppress the immune system, including steroids, chemotherapy and biologic medicines for conditions such as psoriasis and rheumatoid arthritis. Most people have shingles only once, but it can recur.

What causes it?

It is not always clear why the virus reactivates. It is linked to a natural decline in immunity with age, and to anything that weakens the immune system, including illness and some medicines. Stress may also play a part.

Is it hereditary or contagious?

Shingles is not inherited.

You cannot catch shingles from someone else. However, someone who has neither had chickenpox nor been vaccinated against it can catch chickenpox by touching fluid from shingles blisters. You are infectious from the moment blisters appear until every one has scabbed over, which is usually about a week. Until then, keep away in particular from newborn babies, people with weakened immunity, and pregnant women who have never had chickenpox.

What does it look and feel like?

Shingles usually starts with pain, burning, tingling or itching in one area of skin, sometimes with headache, fever or feeling unwell. A few days later, a rash appears in the same area. It begins as red or darker patches that develop into clusters of fluid-filled blisters, which then burst, weep and crust over. The rash usually heals within two to four weeks, taking longer in older people.

Shingles typically affects one side of the body only, in a band or strip that follows the path of a nerve. It most commonly appears on the chest or trunk, but it can affect the face, scalp, arms or legs.

When to seek urgent help

Shingles affecting the forehead, around the eye or the tip of the nose can involve the eye and threaten vision. Seek urgent medical assessment if shingles affects these areas, or if you have eye pain, redness or changes in vision. See a doctor promptly, too, if your immunity is weakened, the rash is extensive, or you are pregnant. Early assessment is important, ideally within three days of the rash appearing.

Complications

The most common complication is post-herpetic neuralgia, which is nerve pain that continues in the affected area after the rash has healed. It is more common in older people and can last months or, occasionally, longer. Other complications include bacterial infection of the rash, scarring, changes in skin colour and eye problems. Less commonly, shingles can cause temporary weakness of the facial muscles, and rare serious complications include pneumonia and inflammation of the brain.

How is it diagnosed?

Shingles is usually diagnosed from the typical pain and the band-like, one-sided rash. If the diagnosis is uncertain, a swab from a blister can be tested for the virus.

What are the treatment options?

Dr Mounsey will confirm the diagnosis and assess whether antiviral tablets are needed, which work best when started within three days of the rash appearing. Treatment also includes pain relief, cool compresses and keeping the rash clean and covered. If nerve pain persists after the rash has healed, known as post-herpetic neuralgia, he can advise on medicines for nerve pain and on referral if needed. He can also advise on the shingles vaccine.

What is the outlook?

Most people recover fully, and the rash usually heals within a few weeks. Some people, particularly older people, have nerve pain that lasts longer after the rash has gone.

Is there a vaccine?

A shingles vaccine is offered on the NHS to people in certain age groups and to some people with a weakened immune system. Your GP can advise whether you are eligible.

More information

British Association of Dermatologists patient leaflet: https://www.bad.org.uk/pils/shingles-herpes-zoster

This page gives general information only and is not a substitute for a consultation. Everyone's skin is different, and what is right for you will depend on your own circumstances. If you are worried about a skin problem, please book an appointment with Dr Mounsey or speak to your GP. If you have a mole or skin lesion that is changing, bleeding or growing quickly, please seek medical advice promptly.