Encyclopedia

Definition

Shingles is a painful infection of the nerves and skin. It is caused by the varicella zoster virus. This is the same virus that causes chickenpox.

Causes

Shingles occurs in people who already had chickenpox. Shingles is a reactivation of the dormant varicella zoster virus. After causing the initial chickenpox infection, the virus does not leave the body. Instead, it settles in the nerve roots near the spinal cord. Once reactivated, the virus travels along the nerve paths to the skin. There it causes pain and a rash.

Herpes Zoster Blisters

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Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Risk factors include:

• Age: 50 or older
• Compromised immune system, as in:
  • People infected with HIV
  • Patients with lymphoma or leukemia
• Excessive fatigue
• Physical or psychological stress
• Radiation therapy

Most cases of shingles occur in those with no known risk factor other than age.

Shingles cannot be transmitted from one person to another. However, a person who has never had chickenpox and never received the varicella vaccine, could get chickenpox if he came in contact with a person who has shingles.

Symptoms

Symptoms include:

• Rash:
  • Appears as a red, slightly raised band or patch often overlain with multiple small fluid-filled blisters
  • Develops on one side of the body or the other, but typically does not cross the midline
  • In severe cases may spread to multiple parts of the body—the so-called “disseminated” zoster
  • Blisters dry out and crust (within several days)
  • Affects mostly the torso and face
• Affected eyes (in severe cases), which can seriously threaten vision
• Pain on the skin at the site of the rash, which is usually severe
• Tingling or itchiness on the skin, which may start a few days before the rash
• Skin in the affected area is unusually sensitive to touch
• Fever
• Headache
• Tiredness

The rash usually disappears within three weeks. In some patients, the pain continues long after the rash has healed. This is called postherpetic neuralgia (PHN). It refers to pain in the affected area for months, or even years afterward. PHN pain is difficult to treat. It can also be very severe.

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam. Usually the rash can be diagnosed by its appearance. In very rare situations fluids are drawn from the blisters and sent to a lab for testing.

Treatment

Shingles cannot be cured. Treatment is focused on alleviating symptoms, speeding recovery, and preventing PHN.

Prevention

There is no proven way to prevent an outbreak of shingles, although undue stress and fatigue may contribute to an outbreak. Future cases of shingles should decrease as more children avoid chickenpox by receiving the varicella vaccine.

The US Food and Drug Administration recently approved a vaccine (Zostavax) for people over 60 who have had chickenpox. The vaccine decreases the likelihood of getting shingles and the severity if shingles does occur.