Fact: Cold sores are caused by a virus.

Cold sores are caused by the herpes simplex virus. There are two types of this virus and cold sores are usually caused by type 1 (known as HSV-1). The other type of herpes simplex virus, HSV-2, usually causes genital herpes. In general, we are infected with HSV-1 when we are children; in the majority of these initial infections, there are no symptoms. Usually, the virus infects our mouths. Some children experience mouth and gum symptoms or a sore throat.

Fact: Cold sores are the result of the virus reactivating in our bodies.

Once HSV-1 has entered our bodies, it never leaves. The virus moves from the mouth to quietly reside in the central nervous system. In approximately one third of people, the virus can "wake up" or reactivate to cause disease. When reactivation occurs, the virus travels down the nerves to the skin where it may cause blisters (cold sores) around the lips, in the mouth or, in about 10% of cases, on the nose, chin, or cheeks. Many people who suffer from cold sores are aware in advance that a cold sore is about to break out - they have a tingling or burning feeling, redness, itching, or pain around their lips or mouth. Cold sore outbreaks may be influenced by stress, menstruation, sunlight, sunburn, fever, or local skin trauma.

Fact: The virus that causes cold sores is infectious.

30%-60% of children 10 years old or younger are infected with HSV-1. They have acquired the virus from family and friends through sharing utensils, toothbrushes, and from kissing. The virus is transmitted from cold sores and also when there are no symptoms, as it can make copies of itself on the skin in the absence of a blister, "asymptomatic shedding". By 50 years of age, 80% of us harbor HSV-1 because we have caught it from someone close to us. Family members who have cold sores can sometimes transmit HSV-1 to newborn babies; this can cause a severe disease called neonatal herpes.

Fact: Early treatment can help eliminate the cold sore.

Some products can accelerate healing if they are used at the prodromal state of the cold sore. Prescription drugs include acyclovir cream or capsules (Zovirax ®), (Denavir ®), and (Valtrex ®). Docosanol cream (Abreva ®) can be purchased without a prescription. Frequent hand washing minimizes the risk of transferring the virus to other people.