Anybody who has ever had the childhood disease chicken pox can develop the painful, blistered rash of shingles, technically known as herpes zoster.
The chicken pox virus lies dormant in a nerve root for years, only to be reactivated later in life when the characteristic rash appears on the area of skin supplied by the affected nerve. The reactivation is sometimes a result of contact with someone – usually a child – carrying chicken pox, but it can also arise from stress or when the body is particularly run down.
The first symptom of shingles is severe pain, for no apparent reason, on one side of the body, usually on the chest, back or neck. A few days later, the blistering rash appears and covers the painful area. It normally disappears in two or three weeks but it can leave scars where the crusts have formed.
Although the rash clears up quite quickly, the pain (known as post-herpetic neuralgia) can persist for months, if not years, afterwards.