A fever blister is spread through direct contact with it or through indirect contact by sharing items such as towels, toothbrushes, razors, drinks, or utensils (see Transmission of Cold Sores).
When the fever blister virus is first transmitted, symptoms do not typically appear. In fact, up to 85 percent of people will not have symptoms with the first infection. However, the body is not able to completely get rid of the herpes virus. Therefore, at some point in the future, the herpes virus can become active again (see Cold Sore Triggers) and cause symptoms.
Fever blister symptoms can vary. Some people may have early symptoms one to three days before the blisters develop. They may feel pain, itching, tingling, or a burning sensation. Others may just develop blisters. These can be small, sometimes painful, fluid-filled blisters around the lips or corner of the mouth. Over several days, the blisters tend to merge and then collapse. A yellowish crust often forms over the sores, which usually heal without scarring within two weeks.
(Click Symptoms of Fever Blisters to learn more.)
There are no fever blister cures; however, the condition will get better on its own, even without treatment. For someone who gets frequent fever blisters, healthcare providers can prescribe one of several medications that are approved for this use. Some medicines are available without a prescription. All of them work best if used at the first signs of an outbreak (symptoms may include tingling, itching, burning, or redness).