the difference between canker sore and cold sore (fever blister)

Source: Centers for Disease Control and Prevention (CDC)

Cold sores, also called fever blisters, are caused by an outbreak of the herpes simplex virus. In other words, cold sores are caused by the reactivation of the herpes simplex virus, which has been dormant in the nerve cells.

During a cold sore outbreak, typically triggered by factors such as sun exposure, stress, fatigue or hormones, the virus wakes up and eventually becomes a visible and contagious sore, usually on or around the lip area.

Cold sores are contagious and usually occur on the lips and on the skin near the mouth. In fact, the herpes simplex virus is contagious. Also, an outbreak of the virus may last from 7 to 14 days.

There are several over-the-counter medications to relieve the symptoms of fever blisters such as pain, burning, and itching. However, Abreva is an over-the-counter medication approved by the FDA to shorten healing time and duration of symptoms of cold sores. Early treatment ensures the best results and therefore apply to affected area on face or lips at the very first tingle of cold sore.

Canker sores, however, occur only inside the mouth--on the tongue and the inside linings of the cheeks, lips and throat. It is worth noting that canker sores are not contagious.

The precise cause of canker sores has not been definitively determined, but stress, food allergies, menstrual periods, and hormonal changes can trigger canker sores. Also, when you bite your tongue or cheek, a canker sore may form. In addition, canker sores may be linked to problems with the body's immune (defense) system.

Canker sores can cause irritation and pain. Most canker sores can be treated with over-the-counter medications. Applying ice to canker sores can also relieve pain and discomfort. Canker sores can usually be expected to heal within 4 to 14 days.