Shingles in Humans

Shingles is a condition that primarily occurs in adults over the age of fifty, although younger people may be affected. It is caused by the third human herpesvirus (HHV-3), also known as varicella-zoster virus (VZV); this is the same virus that causes chickenpox.

Latency

• After the symptoms of chickenpox clear, the varicella-zoster virus goes latent in a nerve cell. As chickenpox affects primarily children and shingles primarily aging adults, VZV can be latent for decades. For shingles to develop, a person must have already had chickenpox.

Causes

• It is not fully understood why a given individual experiences a flare-up of VZV when he does. However, two known risk factors include a weakened immune system and advancing age.

Symptoms

• The first symptom of shingles is pain, ranging from mild to severe; this pain follows the path of the nerve in which the virus is active, generally along one side of the trunk of the body. Later a red rash with blistering develops along the same nerve path.

Treatment

• Antiviral treatment (with acyclovir, valacyclovir or famciclovir) for shingles should be begun as soon as possible after symptoms develop. In combination with antivirals, corticosteroids and topical and oral painkillers are used by physicians to minimize the pain of shingles and, in the case of corticosteroids, to reduce chances of complications.

Complications

• The most common complication of shingles is postherpetic neuralgia, a condition of chronic pain that lasts after shingles rash goes away. This is treated primarily with tricyclic antidepressants and anticonvulsants as well as with corticosteroids, narcotic painkillers and local topical pain relief.

Prevention

• There is an available vaccine for shingles that is recommended for adults over the age of sixty. Although it may not prevent shingles from occurring, the vaccine has been shown to reduce the severity of symptoms as well as reducing the chances of developing postherpetic neuralgia.