When it comes to pollen allergy, grasses are unfortunately often singled out. These plants are indeed responsible for many allergic symptoms, which can have a serious impact on the daily lives of people who are sensitive to it. What are the most allergenic grasses? Where and when do they occur? How to protect yourself from it? We take stock.
Definition: what are grasses?
There are nearly 12,000 grass species worldwide. They belong to the family Poaceae and are present on all continents, in forests, prairies, steppes, savannahs, but also in the middle of our lawns in urban areas.
Ces flowering herbaceous plants are called anemophilous: they need the wind to transport their pollen and thus reproduce (pollination). In other words, it is almost impossible not to be exposed to it in case of pollen peak. From the end of March, and until July – or even until the beginning of autumn – their ears release microscopic grains of pollen which can be transported over tens of kilometres, enter our airways and cause an immune reaction responsible for more or less disabling symptoms.
Important point: not all grasses are responsible for allergies. The pollens most at risk are actually those of forage grasses.
What grasses can you be allergic to? Where to find them (map)?
As stated above, not all grass pollens have the same allergenic potential. Most often they are ornamental grasses classified as follows:
High risk ornamental grasses:
- the baldingere faux-reed ;
- the tufted hick ;
- THE fescues ;
- and the high wheaten (Arrhenatherum elatius).
Moderate risk ornamental grasses:
- the calamagrostis ;
- l’sandrye ;
- the hare tail (oval lagoon) ;
- and the giant trunk.
Good to know: cereal grasses (wheat, oats, rye, barley) can also be responsible for respiratory allergies and food allergies.
In video: “Why are we allergic to pollen?”
When does grass pollen season end?
The grass season generally extends from the end of March to the end of Julywith a peak in May and June.
The symptoms are obviously more intense if the weather is sunny and stays fine, because the pollens remain suspended in the air. On the contrary, when it rains, the rain carries the pollen on the ground with it, which limits the symptoms of allergy sufferers.
To know the distribution and advance of grass pollen in France (in France and overseas), see the article below.
Grass pollen allergy: what are the warning symptoms?
Grass pollen allergy causes a series of symptoms common to all respiratory allergies:
- and flow and/or a congestion nasale (stuffy nose) ;
- of the redness and one tearing at eye level;
- of the itching in the nose, eyes (conjunctivitis) or throat;
- sometimes headache ;
- and in the most serious cases: breathing difficultiess, even a asthma attack (allergic asthma).
What is causing these symptoms? Histamine, a molecule released by the immune system to deal with the allergen it perceives as an aggressor.
Please note: there are cross allergies between pollen and certain foods!
Cross-allergy between grass pollen and food is common among people with seasonal allergies. They are due to a similarity between the proteins of grass pollen and those present in certain foods.
As the table above indicates, it is for example common to be allergic to grass pollen, and at the same time:
- peanuts,
- with wheat flour,
- with melon,
- orange,
- with peas,
- with peppers,
- with potatoes
- and tomatoes.
If in doubt, consult an allergist quickly to determine the exact cause of your symptoms and receive appropriate treatment.
© santemagazine.fr
How to protect yourself during the pollen season?
Grass pollen allergies affect the physical well-being, but also the mental (fatigue, reduced concentration, social eviction, etc.) of people who suffer from it. Fortunately, certain eviction measures make it possible to limit their impact:
- close your windows during the dayventilate your accommodation only in the evening, but avoid sleeping with the window open;
- limit outdoor activities (walks, camping, picnics, etc.) when the pollen concentration is highest (usually in the early morning and evening);
- by car, roll up the windows closed and, if possible, use a recirculated air system;
- wear a hat and sunglasses outdoors (to prevent pollen or stinging fruit hairs from coming into contact with your eyes);
- avoid drying your laundry outside and clean your clothes regularly to get rid of any pollen;
- wash your hair regularly to remove pollen (preferably before going to bed);
- choose single-use contact lenses (disposable at the end of the day), rather than monthly or fortnightly lenses;
- and get regular information via pollen alerts from the RNSA (National Aerobiological Surveillance Network).
Treatment: what drugs to soothe the symptoms of grass pollen allergy?
The first thing to do is to try to avoid pollen respecting preventive measures. But in the middle of the pollen peak, it is sometimes far from enough. It is therefore possible to rely on symptomatic treatments:
- local treatments such as nasal spray or drops, saline or eye drops;
- and second-generation H1 antihistamineswhich block the histamine H1 receptor (responsible for inflammation).
In the event of an asthma attack, it is possible to take Ventolin or corticosteroids with anti-inflammatory properties.
When to desensitize?
Desensitization, also called allergen immunotherapy (ITA), can be prescribed by an allergist in case of severe and persistent allergy despite conventional treatments. It consists of gradually accustoming the body to the allergen to which one is sensitive. Every day — and for many years — patients must take tablets or drops to be placed under the tongue. Thus their immune system will stop panicking in the face of the grass pollen concerned. Note: this protocol can be started from the age of 5 years.
