Shingles is a painful skin rash that usually appears on one side of your waist, but can also affect your chest, back, legs or face. It is more common in people over the age of 40.
Shingles is caused by the varicella-zoster virus, the same virus that causes chickenpox. After you have had chickenpox, the virus remains in your body and lies dormant in your spinal nerves.
You develop shingles if the virus is reactivated, which is most likely to happen in people with lowered immunity. This can be as a result of illness, surgery, ageing, HIV infection or certain medications, such as steroids. Most people will get shingles only once. Rarely, shingles may occur in young children who were either born with chickenpox or had it soon or after birth.
You cannot catch shingles from someone who has shingles or from someone who has chickenpox. However, it is possible to catch chickenpox from someone who has shingles, until the blisters have dried up. People with shingles are extremely contagious from when the rash or blisters appear till when they crust over.
Symptoms of shingles
When the virus is reactivated, it multiplies and spreads down the affected nerve. About two to five days before the rash appears, you may notice some or all of the following symptoms:
- tingling, burning, itching, numbness or a stabbing pain on one side of the body or face
- headache, fever or nausea.
The rash – which can be itchy and intensely painful – is red and looks spotty to start with but the blisters soon join together in bands as the virus spreads along certain nerves located off the spinal cord. The blisters crust over in about seven to 10 days and usually only occur on one side of the body, depending on which nerve the virus affects. The rash usually goes away after about one month.
Complications from shingles
Some people develop complications from shingles. The most common complication is post-herpetic neuralgia. This is when nerve pain continues or recurs more than a month after the shingles rash has cleared. The pain happens because the virus has inflamed and possibly damaged the nerve.
The pain can be burning and continuous or spasmodic and shooting. Some people complain of an itchy, crawling type pain. The overlying skin may feel numb or extremely sensitive to touch. It can be made worse by temperature changes or something touching the skin. While topical pain relievers may offer some relief, many people may need to try several different treatments, including acupuncture or transcutaneous electrical nerve stimulation (TENS) therapy. Post-herpetic neuralgia is more common in people aged over 40, but anybody with this complaint should talk to their doctor.
Other complications include loss of pigment in the skin affected by the rash. Muscle weakness, which is usually temporary, occurs in about 5% of people. It is more likely to occur if the face was affected. Shingles that affects the face may cause permanent visual impairment if the eye is involved or hearing loss.
A second attack of shingles can occur in around 4% of people, but third attacks are very rare.