What is shingles?

Shingles is a painful skin rash that usually appears on the chest, but it can also affect the trunk, back, legs or face. The same virus (Varicella zoster) that causes shingles is also responsible for chickenpox.

Shingles is more common in older people, whereas chickenpox mainly occurs in children. At least one in 20 people will get shingles at some point in their life - it is four times more common in those over 70 years of age.

How do you get shingles?

The virus can be spread through coughing and sneezing. On first becoming infected, you are likely to develop chickenpox (nine out of ten people have had this). However, when you recover from chickenpox the virus remains in your body - it 'hides out' in your spinal nerve cells and can lie dormant for decades.

You develop shingles if this dormant virus is reactivated. This can happen if your immunity is lowered for any reason, and ageing is one factor that causes lowered immunity. Other illnesses that lower your immunity can also bring on shingles.

The shingles rash usually forms along one or two 'belts' of skin (as shown here), usually only on one side.

How do I know if it is shingles?

Once the virus has been reactivated, it multiplies, spreads and causes pain along the path of the nerve that is infected. The rash that follows is painful and usually forms a band, eg, running across the body or down a leg, often on just one side. 'Zoster' comes from the Greek word for 'belt', which describes the pattern of the rash. The area of the rash depends on which nerve supply the virus has been 'hiding out' in.

What will I feel?

Shingles typically begins with pain and itching. The cause of this usually becomes obvious within two to three days when red patches start to form on the skin in the painful area, and the pain may worsen or become a deep aching or burning. You may have headache and fever.

If you are under 50 years of age, shingles pain is often not too severe, but if you are older it can be extremely painful.

The rash then develops into a crop of small blisters, which tend to join and crust over in about seven to ten days. Untreated, the rash usually lasts two to five weeks, and it may leave some scarring. You remain infectious until all of the rash has scabbed over.

How can my doctor help?

Your doctor can ensure that shingles and any complications of shingles are treated properly - so it is important to call your doctor as soon as you think you might have shingles. Possible complications include:

• additional infections around the rash, which might need antibiotic treatment
• involvement of the eye, mouth or tongue (you will be referred to see a specialist for treatment)
• severe or lasting pain (the chance of lasting pain increases the older you are)
• muscle weakness after shingles.

Acyclovir, an antiviral tablet, is now available, which can reduce the severity of shingles and help heal the rash. Antiviral treatment slows the multiplying virus - it is most effective if started within three days of the appearance of the rash.

Your doctor may prescribe an antiviral depending on your age and how badly you are affected. Your doctor will also decide what strength of pain relief is suitable for you as an individual - this depends on what other health conditions you may have.

Lasting pain (neuralgia)

Pain lasting beyond a month from the start of the rash, and when the rash has healed, is called neuralgia - the most common complication of shingles. It happens because the infection has inflamed and possibly damaged the nerve as well as the skin.

This causes your pain senses to become disorganised and overexcitable while the nerves are repaired. The pain improves with time usually, but it is difficult to treat while it lasts.

If you are under 50 years neuralgia is very uncommon but about 50% of those aged over 60 will have pain at one month, and 25% after three months. It can last much longer in a few people. It is also more likely if the pain during shingles was severe or if an eye was affected.

Your doctor can determine the best form of pain relief for you - this may be paracetamol or a stronger pain killer (analgesic). You may be given an analgesic gel to use on the healed areas.

Muscle weakness

About 5% of people with shingles have muscle weakness that follows days or weeks after the pain and rash begin (this is usually in the elderly). It happens because the nerve supplying the muscle has also been inflamed by the virus. It occurs more often on the face than on the body, but most people with muscle weakness recover completely or near completely.

Scarring

Scarring - usually white areas with lost pigment - can occur, depending on how bad the shingles was. The scarred skin may feel like it has lost its feeling. Scarring is also more common in the elderly.

How can I help myself?

• take medications as prescribed - this reduces the severity of shingles and the risk of lasting problems
• call your doctor if the pain becomes too great or if your face becomes affected
• if you cannot sleep, try constructing a support to keep the weight of your bedding off of your body
• keep the rash dry (you can still bathe or shower)
• stay at home until your rash has healed
• when the rash has healed and the crust has fallen off (not before) you can use a moisturiser, or a vitamin E cream, which may help prevent scarring
• after the shingles, avoid exposing the area to sunlight
• if you have lasting pain, wear loose-fitting clothes made of natural fibres and seek help from your doctor early on.

Fortunately, 95% of people who get shingles will never have it again.

If you have more questions about shingles, ask your GP.

Original material provided by UBM Medica (NZ) Ltd. Reviewed in October 2001 by Dr Steve Chambers.