Shingles: Herpes Zoster Diagnosis

  • Diagnosis

    Herpes zoster (HZ) is a nervous system infection caused by the varicella virus, the same virus responsible for chickenpox Figure 01. Herpes zoster (also called shingles) is an infection that primarily occurs in adults 50 years of age or older. Herpes zoster can occur at any time during a given year, and its key symptom is pain. Herpes zoster it is caused by the same virus responsible for chickenpox. Transmission of the virus to someone who has never had chicken pox and has not received the chicken pox vaccination is possible. Such transmission would result in a case of chicken pox, not in a case of herpes zoster illness, however. Shingles, which causes a lot of pain and discomfort, can now be mostly prevented by the recently-approved shingles vaccine.

    Click to enlarge: Chickenpox

    Figure 01. Chickenpox

    In HZ, the varicella virus travels from the spinal cord to the nerve endings in the skin, where it causes an infection Figure 02. After an initial chickenpox infection, the varicella virus travels from the skin into the nerve endings until it reaches the nerves that lie along the spinal column. There, the virus can remain dormant in the body for many years. Factors such as a weakened immune system and psychological stress help the virus to reactivate, spread, and multiply within the nerve cells. The virus then travels along the sensory nerve system until it reaches the nerve endings in the skin, where it produces an HZ rash.

    Click to enlarge: Reactivation of dormant HZ infection

    Figure 02. Reactivation of dormant HZ infection

    Herpes zoster begins with intense pain, itching, and/or numbness in the affected area Table 01. In more than 90% of people, HZ begins with symptoms in and around the affected area. These symptoms precede the HZ rash by about one to three days (although they can occur for up to week before a rash erupts). Symptoms can range from superficial itching, tingling, and burning, to severe, deep, sharp, stabbing pain. The affected area may feel tender and very sensitive when touched. The symptoms can occur either constantly or irregularly. Many people experience flulike symptoms (headache, chills, fever, malaise) and gastrointestinal upset during this time.

    A red, bumpy rash erupts in the same area within three or four days Figure 03. Herpes zoster typically erupts as a red, swollen rash that is limited to the chest, abdomen, face, neck, or forehead. The HZ skin lesions blister within 12 to 24 hours, and become filled with pus. The lesions are painful in 60% to 90% of people, are of irregular size, and are limited to a circumscribed area. New lesions generally continue to appear for up to a week. In most people, the HZ blisters begin to heal within 3 to 4 days, dry and crust over within 7 to 10 days, and then fall off. Although uncommon, some people can experience early symptoms and never develop an HZ rash. This condition is known as “zoster without rash,” or zoster sine herpete.

    Click to enlarge: HZ Rash

    Figure 03. HZ Rash

    Table 1.  Common Symptoms of HZ in Adults

    Common HZ symptoms in Adults
    Phase 1: Early period (one to seven days) with any of the following symptoms confined to one or two areas on the chest, abdomen, arms, neck, face, or forehead: Superficial itching Numbness Tingling Burning Sensitivity to touch Severe, stabbing, or sharp pain Fever Malaise Headache Chills Gastrointestinal upset Phase 2: Herpes zoster infection erupts on the chest, abdomen, arms, neck, face, or forehead: Red, swollen rash confined to one or two areas Pain Itching Fluid-filled, cloudy blisters that continue to erupt for up to one week, and then rupture, or dry up and crust over

    Herpes zoster occurs most often in persons over the age of 50 Table 02. Experts believe that a person’s immunity to the varicella virus decreases with age. Two-thirds of reported cases occur in people older than age 50, whereas the disease is rare in children. By age 80, 1 in every 100 people will develop an infection. Infections are also more severe and longer-lasting in the elderly.

    In addition, HZ discriminates along racial lines: after age 65, Caucasians are one-third more likely to acquire HZ than are African-Americans.

    People with weakened immune systems due to cancer (especially those receiving chemotherapy or radiotherapy), bone-marrow transplant recipients, and HIV patients are at a high risk for HZ, regardless of age. For example, not only do roughly 50% of people with Hodgkin’s lymphoma develop HZ, but up to half of them will have infections that spread to the brain, lungs, and other parts of the body. Finally, HZ can be the first sign of an HIV infection, especially among younger African-Americans.

    Table 2.  HZ Risk Factor Checklist

    ? Age 50 or older (any race) Caucasian age 65 or older HIV+ Hodgkin?s or other cancer Chemotherapy recipient Radiotherapy recipient Organ transplant recipient Long-term corticosteroid use
    If you are healthy and your age is: Your risk for HZ is:
    < 9 years old negligible
    20 to 50 years old .25 in 100
    51 to 79 years old .5 in 100
    80 years and older 1 in 100

    To determine what is causing your condition, your doctor will start with a medical history. A thorough medical history helps the doctor rule out other possible causes of pain and rash. Along with a physical exam, a thorough history can help to determine if you are at risk for complications. You can assist your doctor by thinking about when symptoms began, and how closely they occurred to the appearance of the rash. A period of symptoms lasting one to seven days before the rash eruption can help confirm an HZ infection. If you know that you had chickenpox as a child, or if you didn’t and were recently exposed to a person with HZ, tell your doctor. You should also tell your doctor if you have experienced co-existing infections and diseases (such as HIV and cancer) or recent psychological stress, or if you have used corticosteriod medications for a long period of time.

    A physical examination helps the doctor to determine the severity of your disease. It can also help to assess your risk for complications. In HZ, the lesions are closely grouped, but not uniform in size, and are generally confined to one or two areas on the chest, abdomen, arms, neck, face, and forehead. Pain is usually present in more than 60% to 90% of people with HZ, and the lesions are usually sensitive to touch. Most people will continue to feel pain in the affected area after being touched. About 5% of people with HZ, especially older adults between 60 and 80 years of age, have occasional muscular weakness surrounding or near the infected skin area.

    Herpes zoster can usually be diagnosed by the telltale pain and rash. However, your doctor may take a culture if diagnosis is uncertain, or if healing is delayed for any reason. Laboratory testing is usually unnecessary, especially if an HZ rash is present. However, some people may experience early symptoms and never develop a rash. Additionally, individuals with weakened immune systems and those with HIV often develop an HZ rash that spreads beyond one or two areas, which can make diagnosis difficult. In these circumstances, the doctor may take a scraping from a lesion, or a tissue sample for culturing and confirmation.

    Get a shingles vaccine Table 03.The FDA has recently approved the use of a zoster vaccine in people 60 and older. It is not recommended in people who are pregnant, have a weakened immune system or are allergic to gelatin or neomycin.

    Table 3.  Should You Be Vaccinated Against Varicella Zoster?

    You should check with your doctor to see if you need to receive a varicella-zoster vaccine if you are 13 or older and:
    Live or work in an environment where transmission of the varicella virus is likely (e.g., elementary school teachers, daycare workers, institutional employees, residents of nursing homes and assisted living environments)
    Live or work in an environment where transmission of the varicella virus can occur (e.g., colleges and universities, correctional institutions, the military)
    Work in a healthcare environment and have never had chickenpox
    Are of childbearing age and are not pregnant
    Live in a household with young children
    Are travelling to international locales
    Live with someone who has a weakened immune system
  • Prevention and Screening

    Get a shingles vaccine Table 03.The FDA has recently approved the use of a zoster vaccine in people 60 and older. It is not recommended in people who are pregnant, have a weakened immune system or are allergic to gelatin or neomycin.

    Table 3.  Should You Be Vaccinated Against Varicella Zoster?

    You should check with your doctor to see if you need to receive a varicella-zoster vaccine if you are 13 or older and:
    Live or work in an environment where transmission of the varicella virus is likely (e.g., elementary school teachers, daycare workers, institutional employees, residents of nursing homes and assisted living environments)
    Live or work in an environment where transmission of the varicella virus can occur (e.g., colleges and universities, correctional institutions, the military)
    Work in a healthcare environment and have never had chickenpox
    Are of childbearing age and are not pregnant
    Live in a household with young children
    Are travelling to international locales
    Live with someone who has a weakened immune system

Recommended Reading

Meet the Pharmacists

I'm Kristen Dore, PharmD. Welcome to PDR Health!

Check out my latest blog post on heartburn medication

Shingles: Herpes Zoster Related Drugs

    Shingles: Herpes Zoster Related Conditions