Cold sores, sometimes called fever blisters, are groups of small blisters on the lip and around the mouth. The skin around the blisters is often red, swollen, and sore. The blisters may break open, leak a clear fluid, and then scab over after a few days. They usually heal in several days to 2 weeks.
Cold sores are caused by the herpes simplex virus (HSV). There are two types of herpes simplex virus: HSV-1 and HSV-2. Both virus types can cause sores around the mouth (herpes labialis) and on the genitals (genital herpes).
The herpes simplex virus usually enters the body through a break in the skin around or inside the mouth. It is usually spread when a person touches a cold sore or touches infected fluid—such as from sharing eating utensils or razors, kissing an infected person, or touching that person's saliva. A parent who has a cold sore often spreads the infection to his or her child in this way. Cold sores can also be spread to other areas of the body.
The first symptoms of cold sores may include pain around your mouth and on your lips, a fever, a sore throat, or swollen glands in your neck or other parts of the body. Small children sometimes drool before cold sores appear. After the blisters appear, the cold sores usually break open, leak a clear fluid, and then crust over and disappear after several days to 2 weeks. For some people, cold sores can be very painful.
Some people have the virus but don't get cold sores. They have no symptoms.
Your doctor can tell if you have cold sores by asking you questions to find out whether you have come into contact with the virus and by examining you. You probably won't need any tests.
Cold sores will usually start to heal on their own within a few days. But if they cause pain or make you feel embarrassed, they can be treated. Treatment may include skin creams, ointments, or sometimes pills. Treatment may get rid of the cold sores only 1 to 2 days faster, but it can also help ease painful blisters or other uncomfortable symptoms.
The herpes simplex virus that causes cold sores can't be cured. After you get infected, the virus stays in your body for the rest of your life. If you get cold sores often, treatment can reduce the number of cold sores you get and how severe they are.
There are some things you can do to keep from getting the herpes simplex virus.
After you have been infected with the virus, there is no sure way to prevent more cold sores. But there are some things you can do to reduce your number of outbreaks and prevent spreading the virus.
Learning about cold sores:
Living with cold sores:
Cold sores are blisters on the lips and the edge of the mouth that are caused by an infection with the herpes simplex virus (HSV).
Cold sore blisters usually break open, weep clear fluid, and then crust over and disappear after a few days.
Other symptoms may include:
You may not develop cold sores when you are first infected with HSV. If cold sores do develop when you are first infected, they may be more severe than in later outbreaks. During the first outbreak of cold sores, the blisters may spread to any part of the mouth.
After you become infected, HSV remains in your body and may cause cold sores to return throughout your lifetime (recurrent cold sores).
Recurrent cold sores usually develop where facial skin and the lip meet. About 6 to 48 hours before a cold sore is visible, you may feel tingling, burning, itching, numbness, tenderness, or pain in the affected area. This is called the prodromal stage.
Some common triggers that cause cold sores to return include:
People who have weakened immune systems are more likely than those with strong immune systems to have longer or more severe outbreaks of cold sores. HSV infection may be life-threatening in certain people who have weak immune systems.
Anyone who is exposed to the herpes simplex virus (HSV) is at risk for developing cold sores. But many people have the virus and may never develop cold sores.
People who have weakened immune systems are at an increased risk for having more severe and longer-lasting outbreaks of cold sores.
One form of HSV infection is seen most often in children 1 to 3 years old. This type of HSV infection (primary herpes stomatitis) can cause a high fever and blisters throughout the mouth, which can interfere with the ability to eat. It can be serious in children—they can get quite sick from this illness, although they usually recover without any long-term problems.
Your doctor can diagnose cold sores by asking questions to find out whether you've been exposed to the herpes simplex virus (HSV) and by examining you. No further testing is usually needed.
There are two types of herpes simplex virus: HSV-1 and HSV-2. Both virus types can cause lip and mouth sores (herpes labialis) and genital herpes if your skin comes into contact with either type.
If it is not clear that you have cold sores, herpes tests may be done. The doctor takes a sample of fluid from a sore and has it tested. Having the sample taken is usually not uncomfortable even if the sore is tender or painful.
There is no cure for cold sores, nor is there a cure for the herpes simplex virus (HSV) that causes them. Most cold sores will go away on their own. But medicines may slightly reduce the duration of cold sores and sometimes prevent a future outbreak.
Treatment with medicines depends on whether you are having a first outbreak or a recurrent outbreak or are trying to prevent future outbreaks.
When treating a first outbreak of cold sores, oral antiviral medicines may reduce pain and slightly improve healing time.
For treatment of recurrent cold sores, the following medicines may reduce the severity and duration of the outbreak:1
Oral antivirals may also be taken daily to prevent recurring cold sores, especially in people who have frequent and painful outbreaks.
If you have a weakened immune system and develop cold sores, you may need higher doses of these medicines to control your symptoms or daily doses to prevent outbreaks.
Although it is rare, children and adults with weakened immune systems may also need to take antibiotics during severe episodes of cold sores to treat bacterial infections that may develop.
The first episode of cold sores can be so painful that you may have trouble eating, drinking, and sleeping. A child who has a fever and many mouth sores may need to be encouraged to drink water and other fluids to prevent dehydration.
Adults and older children who have a painful first episode of cold sores may sometimes need a prescription-strength medicated mouth rinse to reduce pain.
Several complementary medicine treatments are available if you wish to try an alternative way to ease your symptoms.
Vitamin C, lysine supplements, and lemon balm are examples of complementary treatments that may provide some relief during a cold sore outbreak. Vitamin C may be taken as an oral tablet, in a cream that can be put on the cold sore (topical cream), or as liquid vitamin C applied to the cold sore. Lysine supplements are taken as pills, and lemon balm is available in a topical cream.
Zinc oxide topical cream may reduce the duration of an outbreak.1
Most cold sores heal on their own. But you can manage your symptoms at home by:
You can reduce the frequency of cold sore outbreaks by taking the following steps:
These measures may help prevent the spread of cold sores in children:
|American Academy of Dermatology|
|P.O. Box 4014|
|Schaumburg, IL 60168|
|Phone:||1-866-503-SKIN (1-866-503-7546) toll-free|
The American Academy of Dermatology (AAD) provides information about the care of skin. You can locate a dermatologist in your area by using their "Find a Dermatologist" tool. Or you can read the latest news in dermatology. "SPOT Skin Cancer" is the AAD's program to reduce deaths from melanoma. There is also a link called "Skin Conditions" that has information about many common skin problems.
|American Social Health Association (ASHA): Herpes Resource Center|
|P.O. Box 13827|
|Research Triangle Park, NC 27709|
|Phone:||1-800-227-8922 Resource Center hotline|
This organization provides information over the phone and online. It offers educational materials, including books, booklets, a bibliography, audiocassettes, videotapes, a quarterly journal, and links to other resources on herpes.
|KidsHealth for Parents, Children, and Teens|
|Nemours Home Office|
|10140 Centurion Parkway|
|Jacksonville, FL 32256|
This website is sponsored by the Nemours Foundation. It has a wide range of information about children's health—from allergies and diseases to normal growth and development (birth to adolescence). This website offers separate areas for kids, teens, and parents, each providing age-appropriate information that the child or parent can understand. You can sign up to get weekly emails about your area of interest.
- Worrall G (2009). Herpes labialis, search date February 2009. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.
Other Works Consulted
- Habif TP, et al. (2011). Herpes simplex section of Viral infections. In Skin Disease: Diagnosis and Treatment, 3rd ed., pp. 224–229. Edinburgh: Saunders.
- Sterling JC (2010). Herpes labialis. In MG Lebwohl et al., eds., Treatment of Skin Disease: Comprehensive Therapeutic Strategies, pp. 303–305. Edinburgh: Saunders Elsevier.
- Wolff K, Johnson RA (2009). Herpes simplex virus (HSV) infection. In Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology, 6th ed., pp. 813–826. New York: McGraw-Hill Medical.
|Primary Medical Reviewer||E. Gregory Thompson, MD - Internal Medicine|
|Specialist Medical Reviewer||Thomas M. Bailey, MD - Family Medicine|
|Last Revised||February 1, 2012|
Last Revised: February 1, 2012
To learn more visit Healthwise.org
© 1995-2013 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.