What Are Cold Sores and Fever Blisters?

Do you ever get blisters on the outside of your mouth when you are going through a particularly stressful time? If you tend to be blister prone when you are stressed or extra tired, you may be experiencing cold sores or fever blisters. These lesions on the outside of the mouth are caused by the herpes simplex virus (HSV-1 or HSV-2) and are highly contagious. Before the blisters appear, you may feel a tenderness, tingling, or burning sensation. Cold sores start out as blisters then crust over. Even though cold sores go away without treatment after 2-4 weeks, the virus can live in your body for years. So what can trigger an outbreak?

Triggers for Cold Sore/Fever Blister

–Emotional Stress

–Weakened immune system


–Viral infection or fever

–Exposure to sunlight and wind

–Hormonal changes (such as menstruation)


A toothbrush can transmit the virus so you will need to be careful when handling it. If you touch the toothbrush to the edge of the toothpaste tube you can spread the virus to the next user. Also, change your toothbrush after any cold sore outbreak. To avoid spreading the virus, take extra time when washing your hands, especially after treating the blisters with ointment using your hands.


Cold sores are their most contagious when the blisters are oozing, but technically the virus can be spread even when you don’t have blisters. It can be spread by sharing utensils, razors, towels, and contact such as kissing. Once you have experienced a herpes outbreak, the virus can lie dormant in the nerve cells in your skin and can show up as another cold sore at the same place as before down the road.


If you experience episodes of herpes cold sores, you can turn to your dentist for help. A dentist can 1) diagnose cold sores herpes through a visual exam, 2) review your medical history, and 3) 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.


Other recommendations your dentist may have include:

–Lowering your stress levels, stress is one of the most common triggers. Yoga or meditation can help.

–Boosting your immunity with extra Vitamin C or a multivitamin.

–Using UV protection with SPF15 (or more) if you spend frequent time in the sun.

Please feel free to give our team a call for more information or if you need help treating a cold sore outbreak.

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