Canker sores and cold sores are often confused for each other, they are not the same. Cold sores are also known as fever blisters, herpes simplex type 1, or herpes labialis. Most people in the U.S. are infected with the type 1 virus by the age of 20.
Cold sores are caused by a virus and are extremely contagious. Cold sores produce groups of small painful fluid-filled blisters which appear outside of the mouth. They can also appear under the nose, around the lips, or under the chin. The blisters develop on a reddened area of skin that is painful. Eventually, the blisters break and ooze. Following that, they form yellow scabs or crusts that finally fall off. The underlying skin is pink. Warning symptoms of itching, burning, increased sensitivity, or tingling sensation may occur about 2 days before lesions appear.
Herpes virus infects and invades the skin, often remaining dormant for months or years before causing active inflammation. Antibodies control the virus unless risk factors develop. Under certain conditions where psychological or physiological stress is high, the virus may become reactivated, leading to a new round of active disease. The blisters of herpes simplex are contagious until they heal.
Untreated, the symptoms will generally go away in 1 to 2 weeks. Antiviral medications taken by mouth may shorten the course of the symptoms and decrease pain. The antiviral medicines work best if you take them when the virus is just starting to come back -- before you see any sores. If the virus returns frequently, your doctor may recommend that you take the medicines all the time.
Herpes sores often come back again and again. The virus remains in the nerve tissue of the face. In some people, the virus may become latent, residing in the nerve cells, with recurrence at or near the original site. Recurrence is usually milder. It may be triggered by menstruation, sun exposure, illness with fever, or stress.
Wash blisters gently with soap and water to reduce the spread of the virus to other areas of skin. An antiseptic soap may be recommended. Applying ice or warmth to the area may reduce pain.
Avoid direct contact with cold sores.