Microsoft word - 07-190 shingles (herpes zoster).doc

Nipigon District Memorial Hospital Infection Prevention and Control

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Area: Infection Prevention and Control
Category: Fact Sheet
Issuing Authority: Infection Control Committee Document Manager: Infection Control coordinator Shingles (Herpes Zoster)

What is Shingles?

Shingles is a very painful disease caused by the same herpes virus that causes chicken pox (varicella
zoster virus). Like other herpes viruses, the varicella-zoster virus has an initial infectious stage, (chicken
pox) followed by a dormant stage. Then, with no warning, the virus becomes active again. This
reactivation of the virus is most likely to occur in people with a weakened immune system. This includes
people with HIV disease, and anyone over 50 years old. Herpes zoster lives in nerve tissue. Outbreaks of
shingles start with itching, numbness, tingling or severe pain in a belt like pattern on the chest, back, or
around the nose and eyes. In rare cases, herpes can infect the facial or eye nerves. This can cause
outbreaks around the mouth, on the face, neck, and scalp, in and around the ear, or at the tip of the
nose. Shingles outbreaks are almost always on just one side of the body. Within a few days, a rash
appears on the skin area related to the inflamed nerve. Small blisters form and fill with fluid. Later they
break open and develop crusty scabs. If the blisters are scratched, someone with shingles might develop
a skin infection. This could require treatment with antibiotics and might cause scars. In most cases, the
rash goes away within a few weeks, but in some cases, severe pain can last for months or even years.
This condition is called "post herpetic neuralgia."
How is Shingles transmitted?
Shingles can only occur after someone has had chickenpox. If someone who has already had chickenpox
comes into contact with the fluid from shingles blisters, they will not "catch" shingles. However, people
who have not had chickenpox could become infected with herpes zoster and develop chickenpox. They
should avoid contact with the shingles rash or with any materials that may have touched the shingles
rash or blisters.
How is Shingles treated?

The standard treatment for shingles is the drug acyclovir, which can be given orally (in pill form) or
intravenously in more severe cases.
Recently, two new drugs have been approved for the treatment of shingles: famciclovir and valacyclovir.
Both famciclovir and valacyclovir are taken three times each day, compared to five times for acyclovir. All
of these drugs work best when they are started within the first three days after the shingles pain begins.
Doctors often prescribe various pain medications for people with shingles. Because the pain of shingles
can be so intense, some researchers have looked for other ways to block the pain. When the herpes
zoster virus inflames nerves, they pump out a chemical messenger called glutamate. Glutamate then
lands on receptors on nearby cells, which transmit pain signals to the brain.
Shingles triggers such a flood of glutamate that some cells stop functioning while others become
hypersensitive. This probably explains why shingles patients can feel great pain even when skin is
touched only lightly.
There are drugs that can block the receptor sites where glutamate lands, and researchers are studying
whether these drugs will help relieve shingles pain.
Nipigon District Memorial Hospital Infection Prevention and Control

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In 1999, the FDA approved a patch form of the anesthetic lidocaine. The patch, called Lidoderm, provides
pain relief for some people with shingles. Because lidoderm is applied to the skin, it has less risk of side
effects than pain medications taken in pill form.

Can Shingles be prevented?

Currently, there is no way to predict an outbreak of shingles, and there is no medication approved to
prevent it. However, researchers have shown that giving older people a stronger form of the chicken pox
vaccine used for children can boost the type of immunity believed necessary to hold the virus in check.
The researchers hope to show that this increased immunity will result in a lower risk of shingles in later
life.
The Bottom Line

Shingles is an unpredictable, very painful disease. It is caused by a re-activation of the virus that causes
chicken pox. Although not directly linked to HIV, shingles seems to occur more frequently in people with
AIDS. Although shingles may disappear within a couple of weeks, severe pain may continue for several
months. There is no known way to prevent outbreaks of shingles. The disease has been treated with
acyclovir, taken five times daily, or given intravenously in severe cases. Two newer drugs, famciclovir and
galaciclovir, seem to be more effective against the pain of shingles and need to be taken only three times
each day. It can be very difficult to deal with the pain of shingles. A newer treatment is an anesthetic
patch that can be applied directly to the skin.

Source: http://intranet.ndmh.ca/upload/documents/InfCon_07_190.pdf