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, but 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. 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. 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. 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 weakened 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. Back to Articles Related Articles Canker Sores Canker sores are fairly common, and they usually go away on their own without treatment. Read this article for teens to find out more, including tips on what to do about the pain. Read More Canker Sores Many people regularly get bothersome canker sores in their mouths. Here's how to help prevent them - and make a kid who has one more comfortable. Read More Genital Herpes Genital herpes is a sexually transmitted disease (STD) that's usually caused by the herpes simplex virus type 2 (HSV-2). Read More Genital Herpes Genital herpes is a sexually transmitted disease (STD). There's no cure for genital herpes, but medicines can help control it. Read More Cold Sores You may have had a cold sore, but what are they exactly? Find out in this article for kids. Read More Cold Sores (HSV-1) Cold sores (also known as fever blisters) are pretty common and lots of people get them. So what causes them and what can you do? Read More Canker Sores Have you ever been rankled by a canker sore? If you have, you know that these small mouth sores can cause major pain. Read More Mouth and Teeth Our mouth and teeth play an important role in our daily lives. Here's a course on the basics - including common problems of the mouth and teeth. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.