What is a cold sore?

A cold sore is a small blister that usually appears on the outer edge of the lip or near the nostrils. Cold sores may appear   one at a time or in little groups. Sometimes they are filled with fluid. They usually crust over and form a scab before they go away. They may last a week or 2 and usually don’t need any special treatment.

What causes cold sores?

Cold sores are caused by a virus called herpes simplex. They are spread by contact with a person who has the virus. Cold sores   are most contagious from the time they first appear until they get dry and crusty.

Once the herpes virus is in your body, you may get cold sores occasionally for the rest of your life. Some people find that   bright sunlight or stress can trigger their cold sores.

How to take care of a cold sore?

  • Wash gently with mild soap and water to keep the cold sore clean.
  • Avoid touching the cold sore with your fingers.
  • Wash your hands often with soap and water to avoid getting an infection in the cold sore. Washing your hands also helps stop the spread of the virus.
  • Always use your own towel. Do not let other people use your towel.
  • Use an ointment (such as Vaseline) on the cold sore to keep it from cracking and drying. This helps prevent infection.
  • Ask your pharmacist for information about ointments that contain an anesthetic. The anesthetic may help stop the pain and itching for a short time. Stop using the ointment once the scab falls off.
  • The best way to apply an ointment is with a clean, cotton-tipped swab (Q-Tip). If you use your finger, be sure to wash your hands before and after.
  • If the cold sore is very painful, you may use a nonprescription pain medicine such as acetaminophen, ibuprofen, naproxen or ASA. Ask your pharmacist which medicine is best for you.

What can you do to prevent cold sores from spreading?

To stop the virus from spreading:

  • Do not have skin-to-skin contact with young children, people with eczema, cancer or AIDS or anyone who has had an organ transplant while you have a cold sore.
  • Do not share forks, spoons, drinking containers, razors or towels while you have a cold sore.
  • Do not kiss others while you have a cold sore.

Contact your pharmacist if:

  • The cold sore gets worse or the skin around it gets red. You may have an infection.
  • The skin around the cold sore becomes red and swollen after using an anesthetic ointment. Stop using the ointment.

You should see a doctor if:

  • The cold sore does not go away after 14 days of care.
  • The cold sore spreads or you feel sick with a fever or swollen glands.
  • You get cold sores often (6 or more in a year). Your doctor may prescribe medicine to help decrease the number.

How to keep cold sores from coming back?

  • Protect yourself from bright sunlight—some people get cold sores at the beach or when skiing. Apply sunscreen (minimum SPF 30) on lips and face 30 minutes before going out into the sun. Wearing a hat with a wide brim can also help.
  • Take good care of yourself—some people find that they get cold sores when they are tired and stressed. If this happens to you, try to reduce the stress in your life or learn how to deal with it better. Getting regular exercise, enough sleep and      eating well can help.
Minor Ailments. © Canadian Pharmacists Association, 2013.  All rights reserved.