How Long is a Fever Blister Contagious?

One of the most common, and most irritating, conditions in the country is the herpes 1 virus, which causes fever blisters and canker sores. Fever blisters generally appear on the outside of the mouth, while canker sores form inside the mouth. These small sores can be quite painful, although they generally will heal without treatment within two weeks. The herpes 1 virus, which is the primary cause of fever blisters, is extremely contagious.

Herpes Type 1

• The herpes simplex virus type 1 is responsible for causing oral herpes, which manifests in fever blisters and canker sores. Herpes simplex type 2, most often associated with genital herpes, may be responsible for up to 5 percent of fever blister outbreaks.

Warning

• The herpes simplex virus should always be considered contagious when a fever blister is present.

Considerations

• The herpes simplex virus is most often spread by kissing, but it may also be spread from touching the sore and touching another person or object a person may come into contact with.

Size

• The U.S. government's Institutes of Health estimate up to 80 percent of the American population is infected with herpes simplex virus type 1, and that there are more than 100 million fever blister outbreaks in the country each year.

Prevention/Solution

• There is no vaccine against the herpes simplex virus and no effective treatment, although some topical ointments may give temporary relief from the symptoms of an outbreak.