What Are the Causes of a Fever Blister?

Fever blisters are also called cold sores. They are typically located on the lips, nose, mouth, and chin. A fever blister is the direct result of the herpes simplex virus type 1 (HSV-1), which is a different strain of the herpes virus than the one that causes genital lesions (HSV-2).

It is estimated that over 85% of adults carry this highly contagious disease. Usually, the virus is caught when a person is between the ages of 6 months and 3 years old. HSV-1 is able to remain dormant in certain cells within the body for years – even decades – before a fever blister outbreak occurs. It is not entirely clear what causes these outbreaks, but a few theories include stress, too many UV rays found in natural sunlight and tanning booths, and a weakened immune system. In fact, fever blisters get their name from their recurrence during times when the body is fighting off a cold or other illness.

Although research is continuing and progress is being made, as of now there is no known cure for the herpes simplex virus – 1. That means there is also no way to cure a fever blister, although there are numerous over the counter, prescription, and homeopathic remedies and medicines that promise to speed the healing of the blister as well as help manage the pain, itching, burning, and tingling sensations that accompany a fever blister. Without treatment, a fever blister will heal on its own within 2 weeks, and as long as it is left alone to run its course there should be no scarring.

Fever blisters will occur outside of the mouth and surrounding areas. They are highly contagious and all necessary precautions should be taken to avoid spreading the disease, especially to young children who are more susceptible to catching HSV-1. Touching and kissing are off limits, as well as sharing cups, cans, utensils, make-up applicators, and even towels. If a fever blister is treated as soon as the beginning stages start (a distinctive tingling or burning sensation) then there is a better chance that the treatment will be effective.

If this is your first fever blister outbreak, you should contact your primary care physician.