Pollen allergy: causes and symptoms
Allergy in a few words
- Respiratory allergies affect many people, especially allergic rhinitis which alone affects about 25% of adults. The symptoms vary and are most often non-specific to the allergy.
- When seasonal, pollens are often involved. There are also cross-reactions with certain plant-based foods, such as fruits, legumes or nuts.
- To complement the medical consultation, biological tests can first confirm the allergic origin of the symptoms, then in a second time will identify the allergens. Understanding the cause of the allergens will facilitate the making of preventive measures and possibly some level of desensitization in order to permanently suppress the symptoms.
- Pollen and pollination periods vary from region to region or county to county. The symptoms encountered in respiratory allergy are varied and there may be cross-reactions with certain foods. Biological tests allow quality diagnosis and management.
What is an allergen?
Allergy is an inappropriate, harmful response of our body, which is called a hypersensitivity reaction. This reaction is triggered by exposure to a substance in our environment that should normally be tolerated, the allergen.
Allergy is related to the synthesis by our body of specific antibodies, immunoglobulins E or IgE. It is these antibodies that will interact with an allergen to trigger the allergic reaction.
The mechanism of allergy takes place in two stages. On the 1st contact, the body becomes aware of the allergen and produces IgE. It is from the 2nd contact that the symptoms appear, defining the allergy.
Note: the phenomena of intolerance are not to be confused with allergy. The mechanisms involved are different and the diagnostic tests are also distinct.
When are pollens found in the air?
Pollens are emitted by plants (trees, shrubs, herbaceous plants) at the time of their reproduction. Not all of them are allergenic. Only pollens that are disseminated via the wind may come into contact with the respiratory mucosa and thus cause allergy symptoms (unlike pollens that are disseminated by insects).
On the other hand, pollens are only present in the air for part of the year, which is specific to each variety. Their presence in the air varies depending on the region and climate. In dry weather, the amount of pollen in the air is greater. Indeed, the rain causes pollen to fall to the ground and reduces its amount in the air we breathe.