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If you have bouts of blisters that show up on your mouth and then crust over, you may be dealing with a virus. You may even know they are coming because you can feel a tenderness, tingling, or burning sensation before they arrive.

Cold sores and fever blisters are caused by the herpes simplex virus (HSV-1 or HSV-2) and are highly contagious. Even though the blisters disappear without treatment after 2-4 weeks, the virus can live in your body for years. Even though most people with the virus never manifest any symptoms, they can be triggered which causes them to erupt. So what triggers an outbreak?

Triggers for Cold Sores/Fever Blisters

  • Emotional Stress
  • Weakened immune system
  • Fatigue
  • Viral infection or fever
  • Exposure to sunlight and wind
  • Hormonal changes (menstruation)


If you experience episodes of cold sores or fever blisters, your dentist can help. Your dentist can:

  • Diagnose cold sores herpes through a visual exam.
  • Review your medical history.
  • Prescribe medications to reduce the outbreak.

A typical medication prescribed is an antiviral drug called acyclovir (Zovirax).  Zovirax comes either as a cream or ointment, and is placed on a blister during any stage of the outbreak to lessen the time you have the outbreak.


Additional recommendations your dentist may provide include lowering your stress levels because stress is the most common trigger, boosting your immunity with extra Vitamin C or a multivitamin and using UV protection with SPF15 (or more) if you spend frequent time in the sun.


Cold sores and fever blisters are their most contagious when the blisters are oozing. It can be spread by sharing utensils, razors, and towels, and you never want anyone to touch your toothbrush with theirs. If you touch the toothbrush to the edge of the toothpaste tube you can spread the virus to the next toothbrush that comes along. Additionally, it is a good idea to change your toothbrush after any cold sore outbreak. And finally, to avoid spreading the virus, take extra time when wash your hands, especially after putting ointment on the sores.

Cold sores and fever blisters don’t have to make your life miserable; there is help! Please feel free to give our team a call at 928-634-5566 for more information or if you need help treating a cold sore outbreak.