Cold Sores

Skin Conditions

Cold sores, also called cold blisters or fever blisters, are small and red or clear. They usually appear on the lip and outer edge of the mouth. They generally dry up within a few days, scab, and the resolve, usually without scarring or marking. They can recur, and may be triggered by stress, illness, sun exposure or other factors.

Cold sores occur due to reactivation of a herpes simplex virus type 1 (HSV-1) infection that was acquired previously, usually in childhood from exposure to an infected relative. The vast majority of the population, as much as 90% per some references, becomes infected with HSV-1 at some point in their lives. The first outbreak of oral HSV-1 infection, especially if infection occurs after early childhood, is a very painful crop of shallow ulcerations on the gums (gingivostomatitis). Cold sores, especially in the first day or two of an outbreak, are very contagious and can spread herpes to others through kissing or oral sex (see the sexual health entry on herpes).


  • Develop techniques to help manage stress, eat healthy foods, and exercise to help support your immune system
  • Avoid direct skin-to-skin contact, such as in kissing, with someone who has cold sores, especially when they have an active outbreak
  • Protect your lips when you go outdoors by using a sunscreen with SPF 15 or greater


Home care   Home Care

  • Take Tylenol® to help reduce pain
  • Apply ice to the area for 15 to 30 minutes, three to four times a day to help reduce pain and swelling
  • Avoid touching the blisters or picking at the scabs. The herpes virus can be transmitted to your finger (herpetic whitlow), or potentially spread to others this way.
  • Wash your hands often
  • Apply Vaseline®, or another lip protector such as Blistex®

Professional care   Professional Care

Seek medical attention if:

  • Blisters appear near or in your eye or on your genitals
  • Outbreaks recur frequently or the sores last longer than two to three weeks (your medical provider may be able to prescribe an anti-viral medication that may reduce the length of your symptoms)