Cold Sore

Cold Sore

Definition

Cold sores are blisters on the lips or around the mouth caused by

herpes simplex virus 1 (HSV-1) and sometimes by herpes simplex virus 2

(HSV-2). Unlike canker sores, which occur inside the mouth, cold sores

are contagious.

Description

Cold sores are painful blisters that develop on the lips or around the

mouth after a person has become infected with the herpes simplex virus.

The herpes simplex virus 1 (HSV-1) that generally causes cold sores is

related to the herpes simplex virus (HSV-2), that typically causes genital

herpes but can also cause cold sores.

People who become infected with HSV-1 develop cold sores

within twenty days of infection, although some may develop symptoms

sooner. The first episode of infection (called the primary infection)

may not have any symptoms or may cause two to three weeks of

fever and blisters/sores both in and around the mouth. In most cases,

the recurrence of symptoms is preceded by a prodrome, or period of

warning symptoms before the main phase of the illness. The prodrome

of cold sores usually consists of a tingling, itching, or burning sensation

that starts one or two days before the blisters appear. The area of

skin where the blisters will erupt may swell up, turn red, and be sore to

the touch.

The sores themselves last for about a week after they erupt. They

appear most commonly on the lips or the area of skin between the upper

lip and the nose.

The blisters are small and thin-walled, filled with a clear fluid,

and become sores after several days. The HSV-1 virus is shed in the

fluid from the sores and can be transmitted to other people if they

come in contact with the blisters. This is the stage in the development

of cold sores when the infection is most contagious. After a few days,

the ulcers form a yellow crust that eventually drops off, leaving an area

of pinkish skin underneath. There is no permanent scar from a cold

sore. People who get cold sores may have one or two recurrences per

year, although some have an outbreak every month and some never

have relapses.

Demographics

According to the National Institutes of Health (NIH), about 80 percent

of people in the United States are infected with HSV-1. Most acquire the

infection as children from contact with oral fluids from an infected

person. Infection with the virus is thought to be equally common in both

sexes and all races and ethnic groups.

People with weakened immune systems, such as patients being

treated for cancer or HIV infection, are at increased risk of getting cold

sores if they are exposed to HSV-1.

Causes and Symptoms

The cause of cold sores is usually herpes simplex virus 1 or HSV-1,

although occasionally type 2 may cause the process. The virus enters the

body through tiny breaks in the tissues lining the mouth, which is one

reason it can easily be spread by kissing or by sharing drinking glasses and

other food utensils. HSV-1 then lies dormant in the cells of the nervous

system until it is activated by stress, an upper respiratory infection, or

some other trigger. It then travels back down the nerves to the skin surface,

usually in the same area of skin each time. HSV-2 oral infection

usually does not have recurrences.

The symptoms of cold sores have already been described. In most

cases, people do not need to see the doctor for ordinary cold sores. They

should, however, make an appointment if they have any of the following

symptoms or conditions:

•

system.

They have HIV or any other illness that weakens the immune

•

The cold sores do not heal on their own by the end of two weeks.

•

The patient’s eyes feel sore or irritated.

•

The cold sores recur frequently.

•

The blisters are unusually large or painful.

Diagnosis

Most people can tell whether they have cold sores by the way they feel

and where they appear. If necessary, the patient

test to tell whether the person is infected with HSV-1. The virus can also

be cultured from the blister fluid or the sore.

’s doctor can run a blood

Treatment

There is no permanent cure for HSV-1 infection. After a person is

infected with the virus, it hides within nerve cells, making it difficult

for the immune system to find and destroy it. HSV-1 remains in the

body, so that cold sores can reappear at any time. Recurrences of oral

herpes can be triggered by a number of factors, including getting the

flu or a cold, not getting enough sleep, having dental work or oral surgery,

getting traveler

injury to the mouth or lips, or exposure to the sun for long periods

of time. The connection between colds and flu in reactivating HSV-1

is the reason why oral herpes is commonly known as cold sore or

fever blister.

The best time to start treating cold sores is during the prodromal

stage before the blisters appear. The doctor can prescribe an antiviral

medication to shorten the length of the outbreak and reduce discomfort.

Other treatments that can be used are topical anesthetics applied

directly to the sores, and aspirin, Advil, or Tylenol to bring down fever.

Some people also find that ice applied to the blisters helps to relieve

discomfort.

’s diarrhea, menstruation, emotional stress, an

Prognosis

Most cases of cold sores heal without long-term problems; however,

HSV-1 can cause an eye infection that may lead to permanent blindness

if fluid from the sores gets into the eyes. For this reason it is

important for people with cold sores to avoid scratching or squeezing

the blisters.

Prevention

The NIH recommends the following measures to lower the risk of

spreading HSV-1 to other parts of the body or to other people, and to

lower the frequency of recurrences.

•

present.

Avoid kissing or close contact with others while the blisters are

•

washcloths, lipsticks, lip balms, razors, and toothbrushes as well

as drinking glasses and food utensils.

Avoid sharing items that touch the mouth. These include towels,

•

the eyes or genital area during an outbreak.

Keep the hands clean. Wash them frequently and avoid touching

•

levels, or being short on sleep.

Try to avoid such common triggers as colds or flu, high stress

•

of time.

•

an over-the counter dietary supplement called lysine, which is an

amino acid (one of the chemical building blocks of proteins).

Patients should check with their doctor to see whether lysine

might be helpful for them.

Some people with frequent recurrences of cold sores benefit from

The Future

Cold sores are likely to continue to be a common health problem in the

general population. Although researchers are working on vaccines against

both HSV-1 and HSV-2, an effective vaccine against either herpes virus

is at least several years away.

SEE ALSO

Canker sores; Genital herpes

For more information

BOOKS

Blenkinsopp, Alison, Paul Paxton, and John Blenkinsopp.

Pharmacy: A Guide to the Management of Common Illness

Blackwell Publishing, 2005.

Smith, Rebecca W.

Guide to Family Dental Care

Symptoms in the. Malden, MA:Columbia University School of Dental and Oral Surgery’s. New York: W.W. Norton, Inc., 1997.

WEB SITES

American Dental Association (ADA).

http://www.ada.org/public/topics/mouth_sores.asp#faq (accessed May 13, 2008).

Mayo Clinic.

cold-sore/DS00358 (updated March 13, 2008; accessed June 27, 2008).

National Library of Medicine (NLM).

http://www.nlm.nih.gov/medlineplus/tutorials/coldsores/htm/index.htm

(accessed June 27, 2008). This is an online tutorial with voiceover; viewers

have the option of a self-playing version, a text version, or an interactive

version with questions.

TeensHealth.

teen/your_body/skin_stuff/cold_sores.html (updated March 2008; accessed

June 27, 2008).

WORDS TO KNOW

Prodrome:

disease when the patient has some characteristic

warning symptoms.

A period before the acute phase of a

Topical:

directly to the skin or the surface

of the body.Referring to any medication appliedCommon Mouth Sores. Available online atCold Sore. Available online at http://www.mayoclinic.com/health/Cold Sores (Herpes). Available online atCold Sores (HSV-1). Available online at http://kidshealth.org/Use sunblock on the lips and face when outdoors for long periods