Shingles, a viral infection caused by the reactivation of the virus that causes chickenpox, varicella-zoster, usually affects people over age 50. The varicella virus lies dormant in cells for many years after the original infection, but reactivation of the virus can occur, either when the immune system is weakened or for no known reason. The activated virus is called herpes-zoster in shingles. Shingles, unlike chickenpox, can occur more than once. Shingles can cause serious disability and pain.
Causes
Complications most often occur in people with compromised immune systems, such as those undergoing cancer treatment; those who have had organ transplant who must take immunosuppressive drugs to avoid organ rejection; and those with HIV infection. Older adults, who often have weakened immune systems, also develop complications more frequently.
Types
Several types of complications can occur in people with shingles. Some of the complications, according to MayoClinic.com, include skin infections; eye problems; nerve pain, called postherpetic neuralgia; and neurological disorders, such as facial paralysis, balance problems, hearing disturbances and encephalitis.
Symptoms
If secondary bacterial infection of the skin occurs from scratching the blisters of shingles, the skin area may become red, purulent and swollen. Scarring can occur at the blister sites, particularly if infection occurs. Facial symptoms such as vision or hearing loss or facial paralysis occur if the virus attacks the nerves that enervate these areas. Encephalitis can occur weeks to months after a shingles outbreak and cause symptoms similar to a stroke, the University of Maryland Medical Center states. Postherpetic neuralgia can cause chronic pain along the affected nerves.
Treatment
Complications often require treatment with antiviral medications such as acyclovir, famciclovir or valacylovir. Physicians may start people at high risk for complications on these medications as soon as the first blisters appear, since the drugs are not likely to work if started more than three days after the first blisters appear, according to the Merck Manual.
Prevention
A vaccine for shingles is available and should be given to people over age 60 with compromised immune systems. The vaccine reduces the risk of developing shingles by 50 percent and reduces the risk of complications such as postherpetic neuralgia by two-thirds, the Merck Manual explains. People can't catch shingles from someone with shingles, although they can catch chickenpox if they've never had it before, according to the National Institute of Neurological Disorders and Stroke.
Recurrence
Shingles occurs more than once in only 4 percent of people, the Merck Manual states. People with weakened immune systems are more likely to have shingles more than once.
