Considering global warming, the period of allergenic pollens has significantly increased, which presents a real agony for all people who are intolerant to it. And their numbers keep increasing. But how exactly does an allergic reaction occur?

What causes an allergic reaction?

Pollens, drugs, foods and more: Almost everyone has had an allergic reaction at least once in their life. Allergies result in reaction of the immune system to a specific allergen. The latter can be swallowed, inhaled or in contact with the skin.

But what exactly do allergens present? So, they are proteins that are large enough to be able to trigger the body’s immune defenses. Moreover, there are other types of allergens which are not of protein origin and which must be broken down by the liver in order to cause an allergic reaction in humans.

Allergic reactions and its various symptoms usually occur in response to a foreign body that the immune system has already encountered. As Inserm experts explain, “Allergy is a disruption of the immune system which corresponds to a loss of tolerance towards substances that are a priori harmless: allergens. “. In case of a second meeting, the so-called process of immediate sensitization or hypersensitivity reaction occurs.

Sensitization is due to the specific antibody immunoglobulin E (IgE) which recognizes allergens and which informs allergic cells to trigger the release of various substances including histamine which causes symptoms like itching, explains to The Healthy allergist Ryan Steele of Yale University.

How our immune system will react to a particular allergen depends on several factors including how we have encountered it. For example, a bee sting received in nature will cause swelling. On the other hand, inhaling pollen to which the individual is allergic will cause an asthma attack. In some cases, it takes hours or even days for the allergen to cause a reaction.

Allergies are becoming more and more frequent not only in France, but throughout the world. Ditto for allergens whose number continues to increase. If over the years your allergic reactions become common, it means you are susceptible to atopy, a hereditary phenomenon. “This term designates the production by the immune system of IgE antibodies specifically directed against an allergenic substance. The main manifestations of atopy are asthma, allergic rhinitis and conjunctivitis and atopic dermatitis. “, explains Inserm.

Better to test yourself for allergens to prevent risky situations and unwanted effects.

Sources :

Inserm : « Allergies ».

The Healthy (juillet 2021) : « What Is an Allergen? How These Particles Cause Allergic Reactions », Leah Groth.