Shingles (herpes zoster)
Shingles (herpes zoster)
What is shingles?
Shingles is a painful blistering rash caused by the reactivation of the virus that causes chickenpox, known as the varicella zoster virus.
The virus is called herpes zoster when it causes shingles and herpes varicella when it causes chickenpox. They were named before it was known that a single virus was responsible for both conditions.
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What causes shingles?
After a person has had chickenpox, the virus lies inactive in the nervous system. When the virus reactivates it multiplies and moves along the nerve fibres to the area of skin supplied by those particular nerves; shingles then appears in this area. Shingles can appear anywhere on the body.
Anyone that has previously had chickenpox may subsequently have an outbreak of shingles.
About 1 person in 5 will develop shingles at some time. Most outbreaks of shingles occur for no obvious reason, but are more likely if the individual:
- is elderly,
- is experiencing physical or emotional stress,
- has an illness that weakens the immune system, such as leukaemia, lymphoma (e.g. Hodgkin’s disease) or HIV infection,
- is taking treatments that suppress the immune system, includingradiotherapy for cancer, chemotherapy, steroid drugs, and drugs taken to prevent organ rejection.
Is shingles contagious?
Shingles is not caught from someone who has shingles or from someone who has chickenpox. It develops when the inactive herpes zoster virus awakens, for example when a person’s immune defences are weaker than normal. However, a person affected by shingles can give chickenpox to someone who has never previously had chickenpox. A person with shingles is infectious from the point of the first blister until the blisters crust over (approximately 7 days).
Is shingles hereditary?
What are the symptoms of shingles?
Before the blisters appear, the first obvious symptom is pain in the area where the virus is reactivating. However, it is important to note that not all people affected by shingles will experience pain. For example, many young people will only experience an itching or mild burning sensation in the affected area.
For those who do experience pain, it is usually in one small area. The pain can range from mild to severe and could be a constant dull, tingling, aching or burning pain/sensation. The rash usually appears a day or two after the onset of pain, and a fever and/or a headache may develop.
What does shingles look like?
Shingles appears as a group of red spots on a pink-red background which quickly turn into small fluid-filled blisters. Some of the blisters burst, others fill with blood or pus. The area then slowly dries, crusts and scabs form. The scabs will fall off over the next two to three weeks.
The rash usually covers a well-defined area of skin on one side of the body only (right or left) and will not cross to the other side of the body.The position and shape of the rash will depend on which nerves are involved. Shingles can affect any area, but the most common areas include the body or down an arm or leg. Less commonly, shingles can affect one side of the face, and occasionally can cause complications affecting one eye.
How is shingles diagnosed?
A diagnosis is usually straightforward, based on the presence of pain, tingling, itching, followed by the rash and the typical appearance/shape of the rash.
If there is doubt about the diagnosis, scrapings may be taken from a blister by the doctor to then be examined under a microscope, or a viral swab test can be taken.
Can shingles be cured?
Shingles usually resolves on its own within a few weeks. Oral antiviral treatment may help clear the rash sooner and can reduce its unpleasant effects.
Rare complications which could occur when the outbreak is on the face:
- Shingles affecting the face (forehead and nose) may spread to the eye leading to inflammation and ulceration in the eye, and later to scarring, which if untreated could lead to vision problems or blindness. Blisters coming up on the side of the nose will alert your doctor to this risk, and you should also get urgent advice from an eye specialist (ophthalmologist).
- Muscles in the area affected by shingles occasionally become weak and there may be temporary facial paralysis on the shingles-affected side of the face.
The pain caused by shingles may persist long after the rash has cleared, particularly in the elderly. This is called postherpetic neuralgia and may persist for a long time. Postherpetic neuralgia requires a very different kind of treatment and the GP will be able to advise the best treatment for this.
To shorten the outbreak
- Antiviral drugs, such as Aciclovir tablets are safe and may shorten the duration, but work best if they are given within the first three days (72 hours) of onset of the outbreak. Therefore, it is very important to get an early diagnosis from the GP as soon as shingles is suspected.
To make it less painful
Rest and taking painkillers may help, i.e. non-steroidal, anti-inflammatories and applying a cool compress.
To deal with complications
If bacteria infect the area of shingles, antibiotic cream or tablets may be prescribed. If shingles affects the eye, a specialist ophthalmic doctor may prescribe eye drops.
To prevent postherpetic neuralgia
Taking antiviral drugs as early as possible when shingles starts may reduce the risk of getting postherpetic neuralgia, and can shorten its duration if it does occur.
To treat the pain of postherpetic neuralgia
Using an anaesthetic ointment (lidocaine 5%) before applying a topical analgesic cream (capsaicin cream) may help. The lidocaine can be bought over the counter, but the capsaicin cream needs to be prescribed by a doctor. Treatments that are sometimes also used include antidepressants and anticonvulsant tablets, as well as pain killers, such as non-steroidal anti-inflammatory drugs.
A vaccine is licensed to prevent shingles in people who are 70 to 79 years old. If you are in this age group, please ask your GP for the vaccination. The shingles vaccine does not help a person who already has shingles or postherpetic neuralgia.
Another vaccine is available to prevent a vulnerable child or adult from catching chickenpox. It is not recommended for routine use in children.
Self help (What can I do?)
- High risk people such as newborn babies, elderly people, people with reduced immunity, and those who have not previously had chickenpox (especially pregnant women) should avoid skin contact with another person’s shingles until the blisters crust over.
- See your doctor as early as possible if you think you have shingles, particularly of the face, as antiviral treatment works best if taken early.
- You may need to take time off work initially; however, you can return to work once the blisters have dried and crusted over.
- Rest if not working. If you have a fever, you may need bed rest for a few days.
This information is provided by the British Association of Dermatologists.
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