Cold sores, also called fever blisters, are a common viral infection. They are tiny, fluid-filled blisters on and around your lips. These blisters often group together in patches. After the blisters break, a crust forms to scab over the sore. They usually heal in two to four weeks without leaving a scar.

Cold sores spread from person to person by close contact, such as kissing. They are contagious even if you don’t see the sores. Because they are contagious, many people get them.

Who gets cold sores?

Here in the United States, people usually get this virus when they are children. Getting kissed by someone who has a cold sore is often how a child catches the virus.

A child can also get the virus by eating from the same fork or spoon as someone who has a cold sore or sharing a towel with a person who has a cold sore.

Adults also catch the virus. That’s why it’s so important for everyone who has a cold sore not to kiss people or have intimate contact until the cold sore forms a scab. To prevent infecting others, it’s also important to stop sharing personal items like towels and razors until the cold sores form scabs.

What causes cold sores?

A virus causes cold sores, most by the herpes simplex virus (HSV). More than half of Americans ages 14 to 49 carry this virus. There’s no cure for HSV infection, and the blisters may return. Antiviral medications can help cold sores heal more quickly and may reduce how often they return. Outbreaks tend to occur less often after 35 years of age.

Once you contract the virus that causes cold sores, you have it for life. After the sores clear, the virus travels to your nerves, where it stays unless it reawakens. Some people have triggers that cause outbreaks. If you get cold sores, it’s likely that something triggers the virus to wake up. Any of the following can be a trigger:

  • Stress
  • Fatigue
  • Illness, such as a cold, fever, or flu
  • Injury, such as a cut, to the area where you have had cold sores
  • Dental work
  • Strong sunlight or sunburns
  • Cosmetic surgery or laser treatment
  • Certain foods
  • Hormonal changes

After getting infected, some people never get a cold sore. Others see some cold sores, but then develop antibodies to the virus and never get another cold sore. It’s also possible to get cold sores throughout your life.

If you contract a cold sore and it becomes a concern, consult a board certified dermatologist. We have answers and treatments.