Shingles is an infection of a nerve and the area of skin supplied by the nerve. It is caused by a virus. It is the same virus that causes chickenpox. Anyone who has had chickenpox in the past may develop shingles.
About 1 in 5 people have shingles at some time in their life. It can occur at any age, but it is most common in people over the age of 50.
How does shingles occur?
Most people have chickenpox at some stage (usually as a child). The virus does not completely go after you have chickenpox. Some virus particles remain inactive in the nerve roots next to your spinal cord. They do no harm there, and cause no symptoms. For reasons that are not clear, the virus may begin to multiply again (reactivate). This is often years later. The ‘re-activated’ virus travels along the nerve to the skin to cause shingles.
In most cases, an episode of shingles occurs for no apparent reason. Sometimes a period of stress or illness seems to trigger it.
The virus usually affects one nerve only, on one side of the body. Symptoms occur in the area of skin that the nerve supplies. The usual symptoms are pain and a rash. Occasionally, two or three nerves next to each other are affected.
The most commonly involved nerves are those supplying the skin on the chest or abdomen. The upper face (including an eye) is also a common site.
The pain is a localised ‘band’ of pain. It can be anywhere on your body, depending on which nerve is affected. The pain can range from mild to severe. You may have a constant dull, burning, or gnawing pain. In addition, or instead, you may have sharp and stabbing pains that come and go. The affected area of skin is usually tender.
The rash typically appears 2-3 days after the pain begins. Red blotches appear that quickly develop into itchy blisters. An episode of shingles usually lasts 2-4 weeks. In some cases there is a rash but no pain. Rarely, there is no rash but just a band of pain.
Shingles are treated with the use of prescription drugs.