Shingles
Shingles, also known as herpes zoster, is a reactivation of the varicella zoster virus, the same virus that causes chickenpox. This condition primarily affects the nervous system and skin, manifesting as a painful rash that typically follows the pattern of a single dermatome on one side of the body. Symptoms often begin with tingling or sharp pain in the affected area, followed by a rash characterized by clusters of blisters and surrounding redness. Shingles is more common in individuals over the age of fifty, although anyone who has had chickenpox is at risk, with about one in three people developing shingles at some point in their lives.
The duration of the illness can range from a few days to several weeks, and while antiviral medications can shorten the illness if administered early, pain relief is also an important component of treatment. It is important to note that while shingles itself is not contagious, the fluid from its blisters can lead to chickenpox in those who have never had the virus. The potential for persistent nerve pain, known as postherpetic neuralgia, is a concern, especially in older adults. Vaccination against chickenpox and shingles can significantly reduce the risk of developing the condition, and ongoing research aims to enhance treatment options for those affected.
Shingles
ALSO KNOWN AS: Herpes zoster
ANATOMY OR SYSTEM AFFECTED: Nervous system, skin
DEFINITION: Reactivation of a viral infection within a nerve cell that causes a characteristic skin rash.
CAUSES: Viral infection with varicella zoster; triggered by stress, illness, decrease in immune function, aging
SYMPTOMS: Tingly, burning, or sharp pain; rash with blisters
DURATION: Three days to several weeks
TREATMENTS: Antiviral medications (acyclovir, famciclovir, valacyclovir); pain relief (cool compresses, anti-inflammatory drugs, mild narcotics)
Causes and Symptoms
Shingles results from the same virus (varicella zoster) that causes chickenpox. All individuals who have had are at risk for shingles. According to the Centers for Disease Control and Prevention (CDC) in 2023, in the United States, one out of every three people will develop shingles at some point in their lives. The CDC estimates that each year there are approximately one million shingles cases. The disease most commonly affects those over fifty, but can develop at any age. After initial manifestations of chickenpox, the virus remains dormant in dorsal root ganglia. Each dorsal root receives sensation from a strip of skin on only one side of the body in a particular distribution called dermatome (map of the skin). Shingles outbreaks occur most commonly on the back, along the distribution of a single dermatome wrapping around one side to the chest or abdomen. They may travel from the upper back to the arm or from the lower back to the leg. Shingles can also occur on the face and, in rare cases, can involve the of the eye.
The virus can stay inactive in the nerve root for decades. It is reactivated by stress, illness, decreases in immune function, or aging. The first symptom is often a sensation of tingling, burning, or sharp pain over the skin area supplied by the affected nerve root. Within several days, a rash appears, characterized by a cluster of blisters with surrounding redness spreading along the dermatomal pattern. The typically does not cross the midline. The blisters scab over in about three days and clear within several weeks. Until the blisters are completely scabbed over, the within the blisters can be contagious via contact. Shingles cannot be acquired from contact exposure, but people who have never had chickenpox can develop chickenpox following exposure to the shingles rash.
The fluid within the blister may be sampled for viral culture to obtain an accurate diagnosis. The diagnosis can usually be made clinically by the characteristic rash. In rare cases, generally in the elderly, nerve pain may persist for months to years after disappearance of the rash, a condition called postherpetic neuralgia.
Treatment and Therapy
If shingles is diagnosed within three days of appearance of the rash, then antiviral medications (acyclovir, famciclovir, or valacyclovir) can be used to stop viral and help to shorten the course of the illness. Treatment also involves pain control with local cool compresses, anti-inflammatory medications, or even mild narcotics. Gabapentin, a drug similar in structure to an inhibitory neurotransmitter, gamma-aminobutyric acid (GABA), is useful against pain experienced in postherpetic neuralgia.
In 1995, the chickenpox vaccine was approved for use in the United States; individuals who are vaccinated against chickenpox will not contract chickenpox and, thus, will never be at risk for developing shingles. In 2006, Zostavax (zoster live) was approved for use in the United States to reduce the risk of shingles in older adults. The vaccine is only a preventive measure and does not treat ongoing shingles.
Perspective and Prospects
The association between chickenpox and shingles was first made in 1888. The virus belongs to a family of viruses called herpes, which is derived from the Greek word herpein, meaning “to creep.”
Because more than 90 percent of adults in the United States harbor the varicella zoster virus, diseases caused by the virus remain significant clinical problems, particularly in the elderly and those with compromised immune systems. Although vaccination, antiviral therapy, and symptomatic therapies provide effective prevention and treatment to many patients, further research on the varicella virus and improved therapies continues.
Bibliography
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