Shingles is caused by the reactivation of the varicella-zoster virus, the same virus which causes chickenpox. After a person has had chickenpox, the virus lies dormant in certain nerves for many years.
Herpes zoster is more common in people with a depressed immune system and in people older than age 50. According to the Centers for Disease Control and Prevention, at least 1 million people will develop shingles annually in the United States.
Signs and Symptoms
Burning or shooting pain and tingling or itching are early signs of the infection, usually located on one side of the body or face. Even after the rash is gone, the pain can continue for months, even years. Active shingles symptoms usually do not last longer than three to five weeks. However, complications do occasionally occur.
Postherpetic neuralgia (PHN) is the most common complication of shingles. It’s characterized by continuous, chronic pain that a person feels even after the skin lesions have healed. The pain may be severe in the area where the blisters were present, and the affected skin may be very sensitive to heat and cold.
People who are at increased risk for PHN include those who have severe pain during active shingles, those with sensory impairment, and older adults. Early treatment of shingles may prevent PHN. In addition, pain relieving medications and steroid treatment may be used to treat the pain and inflammation.
A second common and severe complication of shingles is a bacterial infection on the skin where the lesions are located. Infections can lead to further complications, such as superficial gangrene and scarring. When an infection occurs near or on the eyes, a secondary bacterial infection or corneal opacification (clouding of the cornea) may occur.
Diagnostic Tests and Procedures
In addition to a complete physical examination and medical history, a doctor can diagnose shingles with blood tests and skin scrapings—a procedure in which the skin is gently scraped to determine if the virus is shingles or another virus.
There is no cure for shingles. The disease has to run its course. Early use of oral antiviral medications can shorten the course of the disease and its severity. Otherwise, treatment usually focuses on pain relief. Treatment may include painkillers to help alleviate some of the pain and antiviral drugs to help lessen some of the symptoms and minimize nerve damage. Other treatments may include bed rest, especially during the early phase of shingles, if fever is present; calamine lotion or other topical agents; and cool compresses applied to affected skin areas.
A vaccine to prevent shingles has been approved by the U.S. Food and Drug Administration. The vaccine, Zostavax, is recommended for adults 60 years of age and older. Zostavax is expected to prevent 51% of shingles cases in the United States each year and to reduce the severity of shingles in an additional 67% of cases per year. The vaccine can be administered to individuals in the earliest stages of shingles, where it has been shown to reduce the duration and severity of the shingles episode.