Cold sores (herpes labialis)

Cold sores, or fever blisters, are generally caused by the herpes simplex virus 1 (HSV-1). They appear as a group of vesicles on or around the lips.


70 % of people are thought to have developed antibodies against this virus. Most infected people never show any symptoms.


The warning signs are a burning or tingling sensation where the lesions usually occur. The vesicles, which resemble little blisters, disappear after about ten days. Even when the cold sore itself has disappeared, you are still carrying the virus. The viral load is much reduced, however, and you are much less contagious.

Steps to follow in case of an outbreak
  • Don’t touch the cold sore. If you do, wash your hands immediately.
  • Don’t share objects that have touched your mouth (toothbrush, drinking glass, napkin).
  • Avoid contact with children.
  • Apply ice.
  • Keep your lips well hydrated.
Consult your dentist when :
  • A cold sore does not heal
  • You have frequent cold sores
  • You experience fever or intense pain
  • Your eyes become sensitive to light, a sign that they may also be infected
  • You have swelling in your nose, when the cold sore reappears on your upper lip

There is no medical treatment to eliminate the herpes virus. Your dentist can prescribe medication in the form of cream or tablets, such as anti-viral drugs, that help ease the symptoms and reduce the length and frequency of outbreaks.

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