If you have been infected with the varicella zoster virus, you will most likely get chickenpox. Symptoms may be very mild or severe. When you recover from chickenpox, the virus stays in your body – it 'hides out' in your spinal nerve cells and can lie dormant (inactive) for many years.You develop shingles when this dormant virus is reactivated. This can happen if your immunity is lowered, such as by cancer treatment, HIV or ageing or other illnesses, such as rheumatoid arthritis and type 2 diabetes or during times of stress.
Once the virus has been reactivated, it multiplies, spreads and causes pain along the path of the nerve that is infected, which may be on your chest, back, legs or face but on one side of your body only. The infection usually has 3 stages.
To diagnose shingles, your doctor will ask you about your symptoms and also do an examination. Some people may have pain with no rash or rash with no pain. In such cases, a blood test may be needed to confirm the diagnosis. See your doctor as soon as you think you may have shingles. This should be within 48–72 hours of the rash first appearing, so you can be given antiviral medication to reduce the risk of complications. The earlier that antiviral medication is given, the more effective it is. If it is a holiday period, go to an afterhours clinic.
The treatment for shingles helps to reduce the severity of the rash and its duration and to manage the pain. There are a few things that you can do to ease your symptoms. Antiviral medicines help to fight the virus and other medications can be used to manage the pain.
Your doctor may prescribe an antiviral medication, such as valaciclovir or aciclovir, depending on your age, how long it has been since the rash started and how badly you are affected.
Antiviral medication can reduce the severity and the duration of pain associated with shingles. Antiviral treatment helps by slowing the multiplying virus. It’s best if it’s started within 3 days of the rash and is usually continued for 7 to 10 days, but it may be started up to 7 days after the rash first appears.
Pain from shingles can happen during the infection (called acute pain) or may continue for months to years afterward (called post-herpetic neuralgia).
The choice of pain relief will depend on the severity of the pain. For mild-to-moderate pain, paracetamol or a non-steroidal anti-inflammatory drug (NSAID), such as ibuprofen, is best. If this is not effective, or for moderate-to-severe pain, stronger pain relievers such as codeine, tramadol, morphine, tricyclic antidepressants and gabapentin may be used. Read more about pain relief medications.
About 1 in every 3 people who have had shingles go on to have pain that lasts for months or years after the rash has gone. This is a type of nerve pain or neuropathic pain. The choice of pain relief will depend on the severity of the pain.
In New Zealand, shingles vaccine (called Zostavax) is available for people over the age of 50. It reduces the risk of getting shingles and its complications – you may still get shingles but the symptoms are usually less severe and post-herpetic neuralgia is less likely.
The following links provide more information on shingles.
Shingles Ministry of Health, NZ, 2012Shingles NIH Senior HealthShingles (herpes zoster) DermNet NZ