What Are Cold Sores?

Cold sores are small painful blisters that can appear around the mouth, face, or nose. Cold sores (or fever blisters) are very common. They usually go away on their own within 1 to 2 weeks.

What Are the Signs & Symptoms of Cold Sores?

Cold sores first form blisters on the lips, around the mouth, and sometimes inside the mouth. The blisters then become sores, which can make eating painful. They're filled with fluid, and then crust over and form a scab before they go away.

Sometimes the virus causes redness and swelling of the gums, fever, muscle aches, a generally ill feeling, and swollen neck glands.

What Causes Cold Sores?

The herpes simplex virus type 1 (HSV-1) causes cold sores. This is a different virus from herpes simplex virus type 2 (HSV-2). HSV-2 causes lesions in the genital area called genital herpes. Even though HSV-1 typically causes sores around the mouth and HSV-2 causes genital sores, these viruses can cause sores in either place.

After a child first gets HSV-1, the virus can lie quietly in the body without causing any symptoms. But it can wake up again later from things like:

• other infections
• a fever
• sunlight
• cold weather
• menstrual periods
• stress, like before a big test at school

When the virus reactivates, it can cause tingling and numbness around the mouth before blisters appear.

How Do Kids Get Cold Sores?

Kids can get HSV-1 by kissing or touching a person with cold sores, or by sharing eating utensils, towels, or other items with an infected person. Many kids get infected with HSV-1 during the preschool years.

How Are Cold Sores Treated?

Cold sores usually go away in about 1 to 2 weeks. No medicines can make the virus go away, but some treatments can help make cold sores less painful and not last as long:

• Cold compresses can help with discomfort.
• Prescription or over-the-counter treatments are sometimes recommended by the doctor.
• Cool foods and drinks can help make kids more comfortable.
• Giving acetaminophen may ease pain. Don't give aspirin to kids with viral infections, as it's linked to a rare but serious illness called Reye syndrome.

When Should I Call the Doctor?

Call the doctor if your child:

• is younger than 6 months old and gets a cold sore
• has a weak immune system, which could allow the HSV infection to spread and cause problems in other parts of the body
• has sores that don't heal by themselves within 2 weeks
• has any sores near the eyes or irritation of the eyes
• gets cold sores a lot

Can Cold Sores Be Prevented?

The virus that causes cold sores is very contagious. To help prevent it from spreading to others, anyone with a cold sore should:

• Keep their drinking glasses and eating utensils, as well as washcloths and towels, separate from those used by other family members and wash these items well after use.
• Not kiss others until the sores heal.
• Wash their hands well and often, especially after touching a cold sore.

They also should try not to touch their eyes. If HSV infects the eyes, it can be very serious.

If you're caring for a child with a cold sore, wash your hands often so that you don't get the virus or spread it to others.