Shingles is a viral infection caused by the same virus that causes chickenpox (varicella-zoster virus). Shingles can only develop in a person who has already had chickenpox (varicella). After an episode of chickenpox, the virus does not completely clear, and some particles lie dormant in nerve roots near the spinal cord. They cause no harm, or signs and symptoms, but can re-activate later to cause shingles (herpes zoster).
The majority of the Australian population is at risk of developing shingles, as over 97% of Australian adults over 30 years of age are exposed to the chickenpox virus. Approximately 150,000 new cases of shingles occur every year in the general population in Australia. It is estimated that by the age of 85 years, about half of people will develop shingles.
Shingles may occur at any age, but is more common in people over 50 years of age. Fortunately most people only have shingles once.
If the varicella-zoster virus reactivates, it travels along the nerve to the skin to cause shingles. Symptoms are commonly pain and a rash. The pain is localised, and can range from mild to severe. The pain may be a constant dull, burning or gnawing pain, or sharp and stabbing pain that comes and goes. The rash typically appears two to three days after the pain begins.
The shingles rash can look like chickenpox, but only appears on the area of skin supplied by the affected nerve. New blisters may appear for up to a week and the soft tissues under and around the rash may become swollen due to inflammation caused by the virus. Some people, most often children, have no pain, whereas other people occasionally have pain with no rash. Shingles generally affects only one nerve, on one side of the body.
Shingles can also cause a condition called post-herpetic neuralgia, in which the affected area of skin stays painful after the shingles rash has cleared. This problem is uncommon in people under 50 years of age, but the risk increases with age. Shingles can also cause other problems, e.g. shingles of the eye has the potential to damage eyesight.
Treatments for shingles include anti-viral medicines, pain-relieving medicines (analgesics) and soothing creams, gels and dressings. Antiviral medicines (e.g. famciclovir, valaciclovir, aciclovir) stop the virus from replicating. Early treatment with antiviral medicines can speed healing, as well as reduce pain and other complications. Antiviral medicines must be prescribed by a doctor, and can only be subsidised on the Pharmaceutical Benefits Scheme for treatment of patients with herpes zoster within 72 hours of the onset of the rash.
Pain-relieving medicines such as non-prescription simple analgesics (e.g. paracetamol, ibuprofen) may help to relieve the pain, and you can buy them from a pharmacy. Stronger analgesics (e.g. opioids and medicines for nerve pain) must be prescribed by a doctor. These prescription-only medicines may be required to relieve shingles pain and post-herpetic neuralgia.
Vaccine protection is also available.