infections
Shingles
Introduction
Shingles is a painful skin rash caused by a Overview of Viral Infections that results from reactivation of the varicella-zoster virus, the virus that causes chickenpox. What causes the virus to reactivate is usually unknown, but sometimes reactivation occurs when a disorder or medication weakens the immune system. Shingles causes a painful rash of fluid-filled blisters and sometimes results in chronic pain in the affected area. Doctors diagnose shingles when typical blisters appear on a strip of skin. Antiviral medications, if started before blisters appear, can help relieve symptoms and help them resolve sooner, but pain relievers, including opioids, are often needed. For people aged 50 and over, the shingles vaccine can help prevent shingles. Chickenpox and shingles are caused by the varicella-zoster virus: Chickenpox is the initial infection. Shingles is a reactivation of the virus, usually years later. The varicella-zoster virus is a member of the Overview of Herpesvirus Infections family (herpesvirus type 3). So shingles is sometimes called herpes zoster. During chickenpox, the virus infects collections of nerve cells (ganglia) of the spinal or cranial nerves. The virus remains in the ganglia in an inactive (dormant or latent) state. The virus may never cause symptoms again, or it may reactivate many years later. When it reactivates, the virus travels down the nerve fibers to the skin, where it creates painful sores resembling those of chickenpox. This outbreak of sores (shingles) almost always appears on a strip of the skin over the infected nerve fibers and only on one side of the body. This strip of skin, the area supplied by nerve fibers from a single spinal nerve region, is called a Dermatomes . Sores may also appear on the dermatomes next to the affected dermatome. Unlike Herpes Simplex Virus (HSV) Infections , which can recur many times, there is usually only one outbreak of shingles in a person's lifetime. Fewer than 6% of people have more than one outbreak. Fewer than 6% of people have more than one outbreak of shingles. Shingles may develop at any age but is most common after age 50. The chance of developing shingles increases as people age. Most often, the reason for reactivation is unknown. However, reactivation sometimes occurs when the immune system is weakened by another disorder, such as Acquired immunodeficiency syndrome (AIDS) , or by use of 