Shingles is caused by the same virus that causes chicken pox. In people who have had chicken pox, the virus may make a sudden reappearance, causing a blistering rash and pain in the affected area. This is a shingles outbreak and is usually a result of the immune system being compromised.
The Aftermath of Chicken Pox
When you get chicken pox, the virus that causes it, varicella zoster, is never completely eliminated from your system. Instead, the surviving viruses go into hiding in your nerve cells, usually around your spine and the base of your skull. There it remains dormant. For most people, the virus is never a problem again, but sometimes it reasserts itself. When this occurs, the resulting condition is shingles.
How a Shingles Outbreak Occurs
When the zoster virus comes out of hiding, it affects the nerves under the skin of the affected area. Usually only one area of the body is affected at one time. The area of affected skin is called a "dermatome."
Causes of Shingles Outbreaks
Shingles generally happens when the immune system is not working at its normal level. Under normal circumstances, your immune system will keep the varicella zoster virus in check and it will remain dormant. However, if your immune system is compromised, the virus may become active again and begin to replicate. Most people who get shingles are more than 50 years old. At this age, the immune system is generally not as strong as it was earlier in life. Other factors that may cause the immune system to become compromised are cancer itself and cancer therapy, such as chemotherapy and radiation; HIV/AIDS; non-Hodgkin's lymphoma; and immuno-suppressing medications. Shingles can also be caused by a period of significant mental stress or depression. Sometimes, even a cold or a bad sunburn will be enough to bring about a case of shingles. In rare cases, shingles affects otherwise healthy people with apparently strong immune systems. It is not known why this occurs.
A shingles outbreak usually initially makes itself known as a burning or itching sensation in the affected dermatome. This is generally accompanied by fever, hypersensitivity to touch in the affected area and the "pins and needles" sensation. The pain of shingles can be extreme; it usually described as a burning, aching or throbbing sensation, which may be punctuated by sharp, stabbing pains. After a day or two, a rash will appear on the affected dermatome. This rash will then begin to blister, much like chickenpox. The blisters will fill with blood, and then will begin to crust over and disappear within 7 to 10 days. For most people, the pain stops one the rash is gone, but occasionally the pain will remain for days or weeks after the rash has cleared.
Treatment and Prognosis
Most people who get an outbreak of shingles will never experience it again. While shingles itself is not communicable, it is possible for someone who has never been infected with varicella zoster to get chicken pox from coming into contact with the rash caused by shingles. Shingles is treated with antiviral medications.