Herpes labialis is manifested by the appearance of a bouquet of painful blisters, most often on and around the lips. How to guard against it?

Herpes labialis, what is it?

Known popularly as a "cold sore" or "cold sore", cold sores manifest as a cluster of painful blisters, most commonly on and around the lips. Exceptionally, these small pimples can appear inside the nose, on the edge of an ear, on the chin or on a cheek.

Herpes labialis is an infection caused by a virus, herpes simplex virus type 1 (HSV-1). In rare cases, herpes simplex virus type 2 (HSV-2) may be involved. However, the latter is usually associated with genital herpes.

It is a benign, but unpleasant and often recurring condition. On average, the symptoms disappear on their own in 7 to 10 days.

Mode of transmission of cold sores

Once you are infected with HSV-1, the virus persists for life in the body, without causing permanent symptoms. People who have been infected with this virus are said to be carriers. The virus hides in the nerve ganglia, located at the base of the skull (ganglia of the trigeminal nerve, in particular).

From time to time, for various reasons (fatigue, fever, sun exposure, etc.), the virus “wakes up” and triggers a herpes button, always located in the same region. The frequency of these outbreaks varies greatly from person to person. For reasons that are still unknown, some people will not have recurrences. On the contrary, others will have a few or more per year.

Cold sores are contagious to people who have never been infected with the virus, especially those with weakened immune systems. When lesions appear again, it does not mean that it is a new infection. Therefore, reactivations of the virus are unrelated to recent contact with an infected person.

  • Transmission from one person to another

This virus is very contagious. The incubation period is between 1 and 6 days.

  • Period most at risk

It occurs when the blisters are burst. Transmission then occurs through direct contact with the vesicles or with contaminated objects (utensils, towels, etc.) or through saliva. The fluid in the blisters contains viruses that can penetrate the oral mucosa and infect a new person. Lesions are contagious until they dry up completely.

The virus can also be transmitted through saliva in the absence of symptoms

But this is rarer. Indeed, certain phases of reactivation of the virus occur without causing lesions on the lips. It can even happen that a person contracts cold sores from someone who does not know they are carrying the virus.

  • In adults

Kissing and oral/genital sexual contact are the main routes of transmission. Thus, cold sores can cause genital herpes, and vice versa.

  • Transmission in the same person

Rarely, the virus can be transmitted from the lips to other parts of the body if the fingers touch the lesions, then the mucous membranes of the eyes (conjunctivitis or corneal ulcer), inside the mouth (herpetic gingivo-stomatitis) , nose, and genitals (genital herpes). It also happens that lesions appear on the fingers.

Consequences of cold sores

Bothersome, herpes lesions can occur at the least appropriate time. They do not have significant health consequences, except for people who have a deficient immune system (for example, due to taking medication, AIDS or any other disease that weakens the immune system).

In these people and in young children, HSV-1 infection can lead to serious complications.

  When to consult?

  • In case of lesions that do not heal in 1 to 2 weeks;
  • in case of fever or very intense symptoms during a herpes outbreak;
  • whether recurrences are frequent;
  • in case of illness that affects the immune system;
  • if the eyes become sensitive to light during or after an outbreak, which may be a sign that the infection has spread to the eyes

How to prevent cold sores?

Can we warn?

Since HSV-1 infection is very common and is transmitted mainly during childhood, it is very difficult to prevent it. Nevertheless, the following precautionary measures can be adopted.

Precautionary measures against cold sores

  • Avoid kissing someone who has a cold sore rash until the blisters are completely dry. The fluid inside the blisters contains viruses;
  • avoid using utensils or objects that may have come into direct contact with the saliva or mouth of an infected person, especially during a herpes outbreak;
  • avoid oral/genital contact during an outbreak of herpes labialis or genital herpes in her partner. Herpes simplex virus type 2 (which causes genital herpes) can cause cold sores.

Measures to prevent recurrence in an infected person

  • Determine triggers

First, try to uncover the circumstances that contribute to recidivism. Try to avoid them as much as possible (stress, certain medications, etc.). Sun exposure is a common recurrence factor for many people. In such cases, apply a protective balm against the sun on your lips (SPF 15 or more), in winter as in summer. This measurement is even more important at high altitudes and in tropical regions.

You should also moisturize your lips with a moisturizing balm. Dry and cracked lips indeed offer a fertile ground for the appearance of lesions.

  • Strengthen your immune system

Experts are of the opinion that controlling a herpes virus infection largely relies on vigorous immunity. A fragile or deficient immune system contributes to recurrences. A few key factors:

  • a healthy diet (see the Nutrition file);
  • good sleep;
  • physical activity.

Take antiviral drugs

The doctor can prescribe preventive antiviral tablets in more serious cases: significant and frequent eruptions, people with an immune deficiency or suffering from AIDS. This can help reduce the frequency of recurrences.

 Herpes labialis: how to treat it?

There is no medical treatment that permanently eliminates this virus from the body.Since the symptoms go away on their own in 7 to 10 days, most people choose not to treat them with medication.However, some treatments can relieve symptoms and slightly reduce their duration:

  • paracetamol (Doliprane®, Efferalgan®, etc.) relieves pain;
  • penciclovir cream (Denavir®) in Canada. Applied every 2 hours (except during sleep), penciclovir cream concentrated at 1% slightly accelerates healing. It is obtained by prescription. According to one study, recovery occurs in 4.8 days with pencyclovir rather than 5.5 days with a placebo20. It is always best to apply as soon as symptoms appear. This cream still retains some effectiveness, even if the lesions have been present for a few days;
  • aciclovir cream (Zovirax®). It is applied to the cold sore, 4 to 5 times a day, for 5 days, to reduce the duration of the outbreak22. The cream is most effective when applied as soon as possible, from the warning signs;
  • docosanol cream in Canada. As soon as symptoms appear, applying a 10% docosanol cream to the lesion prevents the virus from multiplying. It is applied 5 times a day until the lesion is healed, for a maximum duration of 10 days. According to a clinical trial, docosanol cream accelerates healing by 18 hours, on average (healing in 4 days rather than 4.8 days with the placebo)