Cold sores are small blisters that usually appear on or around the lips and mouth. In most cases, the blisters will break, creating a scab that eventually falls off. Cold sores are the most contagious when they rupture. But they are actually contagious from the time you first feel any symptoms around your mouth, like tingling or itching, until they are completely healed.

Stages of a cold sore

A cold sore goes through five stages (level of contagion) :

  • Stage 1 (+, low ) – Day 1-2: the initial symptoms such as tingling, soreness and itching
  • Stage 2 (++, moderate) – Day 2-4: fluid-filled blisters begin to form
  • Stage 3 (+++, severe) – Day 4-5: the blisters burst, ooze, and form painful sores.
  • Stage 4 (++, moderate) – Day 5-8: the sores dry out and scab over.
  • Stage 5 (+, low) – Day 8-10: the resolution with healing of the skin after the scab falls off

Cold sores are contagious at all stages with stage 3 being the most infectious due to the opening of blisters that ooze infected fluids.

How long are cold sore contagious?

Cold sores, caused by a type of virus called herpes, are contagious until they completely go away, which usually takes about two weeks. Cold sores are the most contagious when fluid seeps out of the sores. Once the sore has scabbed over, the risk of passing on the virus decrease significantly, but that does not mean it is no longer contagious. Your scab can be broken while eating or smiling, and the fluid can leak out.

Can I give cold sores to other people?

Herpes can be passed on more easily when you are having an outbreak and active sores or blisters are present on the skin. However, the herpes virus can still be spread even if there are no signs or symptoms.

Cold sores are the most contagious when fluid seeps out of the sores.

Warning for babies and people with a weak immune system

Adults who have a cold sore should take care not to kiss babies or not to let babies touch the sore for two reasons.

  1. Cold sores are commonly pretty harmless, but they can become severe in people with not yet fully developed immune systems. The immune system usually protects the body from infection. A person with a weak immune system is likely to get more severe infections than most other people. In that context, the cold sore virus can be dangerous for babies less than 6 months old.
  2. Once the baby has been infected, they will be prone to cold sores for the rest of their lives

The same precaution must be taken with people affected by HIV (human immunodeficiency virus) and people suffering from cancer and treated with chemotherapy. It is, therefore, important to remain particularly vigilant with these people and take steps to avoid infecting them with HSV.

How to be less contagious?

You should minimize any contact with the sores. Always wash your hands after contact with a cold sore to avoid spreading the virus from one site to another, such as the eyes, nose, or fingernails.

While having any symptoms of cold sores, you should also avoid:

  • kissing
  • sharing lipsticks, kitchenware, glasses or anything else that may have been in contact with your cold sores
  • sports that involve physical contact

Until the cold sore blisters and scabs have completely gone away, you have to protect yourself and other people from infection. Air tight and water tight medical dressings such as COMPEED® Cold Sore Discreet Healing Patch helps prevent the virus from spreading to another area of your body as well as protecting others.