An infection, also known as shingles, that causes a painful rash of blisters along the path of a nerve
- Most common between the ages of 50 and 70
- Gender, genetics, and lifestyle are not significant factors
Herpes zoster, often known as shingles, is characterized by a painful crop of blisters that erupts along the path of a nerve. The rash commonly occurs on only one side of the body and usually affects the skin on the chest, abdomen, or face. In older people, discomfort may continue for months after the rash has disappeared. This prolonged pain is called postherpetic neuralgia.
Herpes zoster infection is caused by the varicella zoster virus. This virus initially causes chickenpox but then remains dormant in nerve cells. If the virus is reactivated later in life, it causes herpes zoster. The reason for reactivation is unknown, but herpes zoster often occurs at times of stress or ill health. The disorder most commonly occurs in people aged 50–70 years. People with reduced immunity, such as those with AIDS (see HIV infection and AIDS) or those undergoing chemotherapy, are more susceptible to herpes zoster. People with AIDS are particularly likely to have severe outbreaks of herpes zoster.
The varicella zoster virus is easily spread by direct contact with a blister and will cause chickenpox in a person who is not immune to the disease.
What are the symptoms?
Initially, you may experience tingling, itching, and a sharp pain in an area of skin. After a few days, the following symptoms may also develop:
Painful rash of red spots that turn into fluid-filled blisters.
Within 3–4 days, the blisters form scabs. These scabs heal and drop off within 10 days but may leave scars in some people. If a nerve that supplies the eye is affected, it may cause a potentially serious inflammation of the cornea (see Corneal ulcer). Rarely, infection of a facial nerve causes weakness or paralysis on one side of the face (see Facial palsy).
What might be done?
Herpes zoster can be difficult to diagnose until the rash appears, and severe pain around the ribs can be mistaken for the chest pain of angina. Your doctor may prescribe antiviral drugs to reduce the severity of the symptoms and the risk of postherpetic neuralgia. If your eyes are affected or if you have reduced immunity, you will need immediate treatment with antiviral drugs. Painkillers may help to relieve discomfort, and gabapentin (see Anticonvulsant drugs) may help to relieve the prolonged pain of postherpetic neuralgia. Most people who develop herpes zoster recover within 2–6 weeks, but up to half of all affected people over the age of 50 develop postherpetic neuralgia.
A single attack of herpes zoster does not provide immunity to the disease, and the infection may recur.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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