Shingles is a viral infection that occurs in some adults who have previously had chickenpox. It often causes a rash, which may be a single strip of blisters around one side of your body.
It is a contagious infection, so if you have it you should keep away from others, particularly if they have never had chickenpox or shingles.
Shingles is caused by the varicella-zoster virus, the same virus that causes chickenpox. When you recover from chickenpox the virus lies inactive in nerve tissue near your spinal cord and brain. Years later it may reactivate to cause shingles.
Although not life-threatening, shingles is painful. Early diagnosis and treatment can help shorten a shingles infection as well as reduce the chances of complications.
Symptoms
Pain is usually the first symptom of shingles. It may be the only symptom. However, commonly a rash appears a few days after the pain begins.
The rash usually only affects a small section of one side of your body. It may develop into fluid-filled blisters that break open and crust over. The rash may be itchy, painful, have a burning sensation and be accompanied by numbness or tingling and sensitivity to touch.
Some people also experience fever, headache, sensitivity to light and fatigue. Sometimes the shingles rash occurs around one eye or on one side of the neck or face.
Depending on its location, the pain, if unaccompanied by the rash, may be mistaken for a symptom of problems affecting the heart, lungs or kidneys.
Suspected shingles infections should be treated as soon as possible, especially if the rash is widespread and painful or the pain and rash occur near an eye. If near the eye, this infection can lead to permanent eye damage.
If you are 60 years or older, seek professional medical assistance urgently as age significantly increases your risk of complications.
Urgent treatment should also be sought if you or someone in your family has a weakened immune system, for example, due to cancer, medications or chronic illness.
Causes
The cause of shingles is the varicella-zoster virus, which is part of a group of herpes viruses that include viruses that cause sores and genital herpes. For that reason, shingles is also known as herpes zoster. However, the virus that causes chickenpox and shingles is distinct from those that cause cold sores and genital herpes.
While it is known that the varicella-zoster virus causes both chickenpox and shingles, not everyone who has had chickenpox develops shingles. It is unclear why some people who have had chickenpox develop shingles later in life while others do not.
It could be due to lowered immunity to infections as you grow older. Shingles is more common in older adults and people who have weakened immune systems.
The varicella-zoster virus is contagious. It can be transmitted to anyone who is not immune to chickenpox. This usually occurs through direct contact with the open sores of the shingles rash. Once infected, the person will develop chickenpox, not shingles.
Chickenpox can be dangerous to some people so you should avoid physical contact with anyone who has not yet had chickenpox or the chickenpox vaccine. Make sure you also avoid people with weakened immune systems, pregnant women and babies until your shingles blisters have healed.
Risk factors
Anyone who has ever had chickenpox can develop shingles. Factors that may increase your risk of developing shingles include your age. Being older increases your chances of getting shingles as it is commonest in people older than 50.
You have a higher chance of having shingles if you suffer from diseases that weaken your immune system, such as HIV, AIDS and cancer. If you are undergoing cancer treatment you are also at a higher risk as radiation or chemotherapy can lower your resistance to diseases.
Some medications such as those designed to prevent rejection of transplanted organs can increase your risk of shingles. Prolonged use of steroids such as prednisone can also make you more vulnerable to shingles.
Complications
Possible complications from shingles include postherpetic neuralgia, which occurs when damaged nerve fibres send confused and exaggerated messages of pain from your skin to your brain. This means shingles pain may continue long after the blisters have cleared up.
If shingles blisters are not properly treated, bacterial skin infections may develop. Shingles in or around an eye can cause painful eye infections that may result in loss of vision.
Neurological problems can also develop. Depending on which nerves are affected, shingles can cause inflammation of the brain, facial paralysis as well as hearing or balance problems.
Diagnosis
Your doctor can diagnose shingles by asking about your medical history and your symptoms and performing a physical examination. The doctor may also test small amounts of material from your blisters.
Treatment
Antiviral drugs can help you heal faster and reduce your risk of complications. They are most effective if you take them within three days of the start of a rash so you should see your doctor or a professional healthcare provider as soon as possible.
The most common antiviral drugs prescribed for the treatment of shingles include Acyclovir (Zovirax), Famciclovir (Famvir) and Valacyclovir (Valtrex).
Treatment to relieve shingles pain can include taking anticonvulsant medicines as well as some antidepressants such as amitriptyline. You can also take colloidal oatmeal baths, apply medication lotion and use cool compresses on the affected areas.
Numbing medications such as lidocaine and over-the-counter drugs which include acetaminophen or ibuprofen can provide some relief. Prescription painkillers such as codeine also provide relief.
Prevention
Most people who get shingles only have it once. However it can come back, usually in people with weakened immune systems. It is therefore advisable to get a shingles vaccine that may help prevent you from getting the virus.
