Cold sores


Does the sudden appearance of a cold sore make you want to hide? It’s no secret that this type of lesion near the lips is quite unpleasant… and when you get one, you just want to get rid of it as quickly as possible. Here is some information that will help you reduce its impact and, more importantly, prevent you from spreading the virus.

Les feux sauvages

All about cold sores

You feel a sensation of tingling or itchiness near your lips and you think: oh no, here we go again! Indeed, an unsightly cold sore is developing on your face. Cold sores, also known as herpes labialis, are caused by the herpes simplex virus I, which affects up to 80% of the population. The first time you come into contact with it, also known as the primary infection, it is possible for it to go unnoticed. However, herpes labialis is a recurrent infection in 20 to 40% of affected individuals since the virus never completely disappears. This translates to an average of 2 to 3 cold sores per year, although some people can get them much more or much less often.

It is important to note that herpes labialis is highly contagious. Some measures can prevent the virus from spreading, though:

  • avoid close contact (ex: kissing) with others until the cold sore has disappeared;
  • avoid sharing personal objects (ex: toothbrush, utensils, makeup);
  • don’t touch the sore needlessly;
  • wash your hands after touching the sore;
  • avoid contact between the mouth and genital organs during sexual intercourse.

The evolution of a cold sore

A cold sore goes through several phases before completely disappearing from the face. Recognizing it during the first phase, the prodrome, will enable you to act quickly and reduce healing time.

Table 1: The phases of a cold sore

Phase of cold sore

Description of phase


This phase occurs before the appearance of a lesion on the edge of the lip. This period lasts less than 24 hours. You feel a sensation of itchiness, tingling, pain or burning. Not everyone feels the prodrome.


The prodrome is followed by the appearance of redness near the lip, which can last one or two days.


Small bumps filled with clear fluid appear. There is also swelling in the area.


Blisters break open and the fluid dries up, forming a scab. It can remain for several days.


After about 8 to 10 days, the skin regenerates and all traces of the cold sore are gone.

What can trigger a cold sore

Herpes simplex is a virus that remains dormant for a while before reactivating again, which is why herpes labialis is a recurrent infection. Some factors are known as triggers for cold sores, including:

  • fever;
  • an infection, such as a cold;
  • menstruation;
  • fatigue;
  • stress;
  • exposure to the sun or tanning salons;
  • dry lips;
  • sore or irritation on the lips;
  • weak immune system.

In addition, because cold sores are contagious, you must be careful when you come in close contact with someone who has such a lesion.

Over-the-counter treatments

Cold sores are not dangerous and heal even without treatment, usually in 8 to 10 days. Consequently, many people choose not to treat them. But because most people don’t enjoy having a rather obvious lesion on their face, there are treatments available to limit the extent and duration of a cold sore. Two over-the-counter medications are approved in Canada for this purpose:

  • AbrevaMD (docosanol);
  • LipactinMD (zinc and heparin).

For optimal effectiveness, you must, as much as possible, start applying these products in the first phase of the cold sore (prodrome). You must also follow the manufacturer’s instructions. These products are very safe and have little side effects.

Once the cold sore is crusted over, you can apply a hydrating agent, such as cream, ointment or balm. This can make it more comfortable for you and help with healing.

People often tend to apply all sorts of products on a cold sore to make it go away. But when the cold sore is in the prodrome, redness or blister phase, do not use anything other than specific cold-sore medication; otherwise, your cold sore could get worse or larger.

Always seek the advice of your pharmacist before using over-the-counter medication.

Prescribed medication

If you are predisposed to having several episodes of herpes labialis throughout the year, your doctor may want to prescribe a different treatment than the ones sold over the counter. Antiviral drugs (acyclovir, valacyclovir and famciclovir), which are available in creams or tablets to take orally, are even more effective than non-prescription medications. Again, the most important thing is to use them as soon as possible, i.e. in the prodrome phase or when the lesion first appears. Here’s a handy tip: always keep the required antiviral doses for a cold sore in your home so that you can take them quickly.

Helpful advice

In addition to medication, some measures should always be followed to avoid getting an unpleasant cold sore and spreading the virus. For example:

  • Don’t pop your blisters because the fluid inside is contagious.
  • Apply an ointment on the scab to keep it moist and prevent cracks, which increase the risk of bacterial surinfection.
  • Wash your hands often throughout the day, especially if you have a tendency to touch the cold sore.
  • Discard all makeup that has come in contact with the cold sore in order to prevent reinfection.
  • Avoid triggers (ex: apply sunscreen or lower your level of stress).

People who suffer from herpes labialis often call upon their pharmacist. He or she can help you find the right product, remind you of its instructions for cold sores and determine situations that may require a doctor’s visit. Don’t hesitate to ask; your pharmacist can help you tame your cold sores!

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