Cold Sores: Care Instructions

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Your Care Instructions

Cold sores are clusters of small blisters on the lip and skin around or inside the mouth. Often the first sign of a cold sore is a spot that tingles, burns, or itches. A blister usually forms within 24 hours. The skin around the blisters can be red and inflamed. The blisters can break open, weep a clear fluid, and then scab over after a few days. Cold sores most often heal in 7 to 10 days without a scar. They are sometimes called fever blisters.

Cold sores are caused by a virus called the herpes simplex virus. This virus also causes some cases of genital herpes. The virus can spread from a sore in the genital area to the lips. Or it can spread from a cold sore on the lips to the genital area.

Cold sores most often go away on their own. But if they are severe, embarrass you, or cause pain, your doctor may prescribe antiviral medicine to relieve pain and help prevent outbreaks.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

How can you care for yourself at home?

  • Wash your hands often. And try not to touch your cold sores. This will help to avoid spreading the virus to your eyes or genital area, or to other people. This is more likely to happen if this is your first cold sore outbreak.
  • Place ice or a cool, wet towel on the sores 3 times a day. Do this for 20 minutes each time. It may help to reduce redness and swelling.
  • If you are just getting a cold sore, try over-the-counter docosanol (Abreva) cream to reduce symptoms.
  • If your doctor prescribed antiviral medicine to relieve pain and help prevent outbreaks, be sure to follow the directions.
  • Take an over-the-counter pain medicine, such as acetaminophen (Tylenol), ibuprofen (Advil, Motrin), or naproxen (Aleve), as needed. Read and follow all instructions on the label.
  • Do not take two or more pain medicines at the same time unless the doctor told you to. Many pain medicines have acetaminophen, which is Tylenol. Too much acetaminophen (Tylenol) can be harmful.
  • Avoid citrus fruit, tomatoes, and other foods that contain acid.
  • Use over-the-counter ointments to numb sore areas in the mouth or on the lips. These include Orajel and Anbesol.
  • Do not kiss or have oral sex with anyone while you have a cold sore.

To prevent cold sores in the future

  • Avoid long exposure of your lips to the sun. (Wear a hat to help shade your mouth.)
  • Do not kiss or have oral sex with someone who has a cold sore. Do not have sex or oral sex with someone who has a genital herpes outbreak.
  • Using lip balm that contains sunscreen may help reduce outbreaks of cold sores.
  • Do not share towels, razors, silverware, toothbrushes, or other objects with a person who has a cold sore.

When should you call for help?

Call your doctor now or seek immediate medical care if:

  • Your symptoms are painful and you want to try antiviral medicine.
  • You have signs of infection, such as:
    • Increased pain, swelling, warmth, or redness.
    • Red streaks leading from a cold sore.
    • Pus draining from a cold sore.
    • A fever.
  • You have a cold sore and develop eye pain, eye discharge, or any changes in your vision.

Watch closely for changes in your health, and be sure to contact your doctor if:

  • The cold sore does not heal in 7 to 10 days.
  • You get cold sores often.

Where can you learn more?

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The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.