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Cold Sores: 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. They are sometimes called fever blisters. 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 often heal in 7 to 10 days with no scar.

Cold sores are caused by the herpes simplex virus. The virus is spread by skin-to-skin contact. That means that if you have a cold sore and kiss another person, that person could get a cold sore too.

This is the same virus that causes some cases of genital herpes. So if you have a cold sore and have oral sex with someone, that person could get a sore in the genital area.

Cold sores will often go away on their own. But if they're painful, ask your doctor about a prescription antiviral medicine. It can relieve pain, help prevent outbreaks, and shorten the healing time.

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 or nurse advice line (811 in most provinces and territories) 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.
  • To help relieve pain, try placing a cold, wet towel on the sore. This can also reduce swelling.
  • If you are just getting a cold sore, try using over-the-counter docosanol (Abreva) cream to reduce symptoms.
  • If your doctor prescribed antiviral medicine to relieve pain and shorten the healing time, 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. No one younger than 18 should take aspirin. It has been linked to Reye syndrome, a serious illness.
  • 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, such as Anbesol or Orajel, to numb sore areas in the mouth or on the lips.
  • 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 sunlight. (Wear a hat to help shade your mouth.)
  • Use lip balm that contains sunscreen, which 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.
  • For frequent or painful cold sores, try taking an antiviral medicine daily to decrease outbreaks.

When should you call for help?

Call your doctor or nurse advice line 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 or nurse advice line if:

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

Where can you learn more?

Go to

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Care instructions adapted under license by your healthcare professional. If you have questions about a medical condition or this instruction, always ask your healthcare professional. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.