Herpes zoster, commonly known as shingles, is caused by the varicella zoster virus (VZV), the same virus that causes chickenpox. Following chickenpox infection the virus lies dormant in the nerves near the spine and may re-emerge many years later as shingles. Shingles most commonly affects older adults or people of any age with a weakened immune system.
A person infected with varicella zoster virus will usually get chickenpox. The disease may be mild or severe. However, it is possible to be infected with the virus and show no symptoms. Once someone has been infected the virus will lay dormant but be kept in check by the body’s immune system. As the immune system weakens the risk of shingles can increase. Certain medications, major surgery, skin burns, HIV, cancer or emotional stress and increasing age can all result in the immune system being weakened. Therefore, it is possible to get shingles with no history of clinical chickenpox. It is also possible to get shingles more than once and again this risk increases with age.
Shingles is characterised by a painful unilateral (one side of the body) rash, usually in one area of the body. The first sign of shingles is often a burning, sharp pain, tingling or numbness under the skin on one side of your body, especially back, abdomen or face, which can lead to severe itching or aching. Tiredness, fever, chills, headache and upset stomach may also occur. Approximately 1 to 14 days after the onset of pain, a rash of small blisters appear on a reddened area of skin. The burning pain and blisters follow a nerve pathway, often extending front to back on one side of the body or head. As with chickenpox, after a few days the blisters will crust over. Over the course of several days to weeks, the crusts will drop off and the skin will heal.
As soon as the symptoms appears, a doctor can prescribe antiviral treatments, which may speed up recovery and help to prevent long term complications. The earlier in the infection the medication is prescribed the more effective it is. Pain relief, such as paracetamol, may also be required. A moistened, cool cloth on the affected area may help to relieve discomfort.
Shingles of the face or scalp may result in headaches and weakness on one side of the face (causing a droop on the affected side). It may take several months for this weakness to clear.
Shingles may affect the eye causing ulceration, inflammation or glaucoma and occasionally loss of vision. Rarely, shingles affects the ear causing earache, hearing loss, vertigo and/or tinnitus. The rash may become infected and body organs may be affected.
Chronic nerve damage can occur, particularly in people over 50 years of age, causing nerve pain (neuropathy), numbness or tingling for months or years after on the area the rash has cleared from. This is known as postherpetic neuralgia.
As with chickenpox, the blisters of shingles contain the varicella-zoster virus. It is possible for chickenpox to be passed to a close contact of someone with shingles who are not immune to varicella, such as between a grandparent and an infant. Covering the rash is recommended to prevent transmission.
Shingrix is a recombinant subunit vaccine indicated for the prevention of shingles and associated complications. Two doses are recommended but not funded for individuals aged from 50 years. As a non-live vaccine, it can be given to people with severe immunocompromise and people who may have had Zostavax previously.