People who have had chickenpox (90% of the population) can later develop shingles (herpes zoster). It occurs when the varicella zoster virus—which causes chickenpox and remains then dormant—re-activates. Shingles is known for causing a painful rash on one side. Antiviral medications are an extremely effective treatment for shingles, as long as they are commenced within 1 or 2 days of the rash appearing.
The rash is made up of many small blisters and it usually appears on one side only, in the area supplied by a single nerve root from the spinal cord. The pain is often sharp and burning in nature. If shingles is not treated, it can last between 2 to 5 weeks.
Attacks of shingles aren't always the same. Sometimes there might be pain before the rash appears, and sometimes there might not even be a rash. This can make diagnosis difficult.
When you first come into contact with the VZV virus, you develop chickenpox. After that, the virus lies dormant in your body, usually for many years. When the virus “wakes up” it can cause shingles.
When the immune system is weak, for example, after a transplant, when on treatment for cancer, or in people with AIDS, shingles is more likely to occur. But anyone who has ever had chickenpox can develop shingles. If you are young and healthy and develop shingles, it does not necessarily mean there is a problem with your immune system.
The antiviral drugs valaciclovir and famciclovir reduce the pain and the duration of the rash, but to be effective they must be taken in the first few days.
Occasionally a swab test might be helpful in confirming the diagnosis, but usually a doctor can tell it’s shingles from the one-sided pain and rash.
If you have shingles, you can’t pass on the VZV virus to people who have had shingles, because it is already dormant in their body. People who have never had chickenpox have a small risk of coming into contact with the virus if they touch the rash of someone who has shingles. Usually the rash is on areas that are covered by clothing, which provides protection.
This is called post-herpetic neuralgia (PHN). The risk of PHN is highest in people who have not received antiviral and pain relief treatment for shingles. PHN can be a very painful and debilitating condition which can continue for up to a year.
The mother is already carrying the VZV virus before developing shingles, and there is no increase in the risk of passing it on to the fetus if shingles develops.
Last Reviewed: 01 December 2010