Pollen: what is it?
“Pollens are microscopic particles emitted by the entire plant kingdom” describes Julien Cottet. Dispersed by the wind, their contact with the eyes, the nasal mucous membranes or the respiratory tracts causes a more or less important inflammation in allergic subjects. Each plant family pollinates at a different time of the year, so “contrary to popular belief, spring is not the only pollen season! »Specifies the allergist. However, pollens are more prevalent in the dry seasons since the rain prevents their dispersion in the air by pinning them on the ground.
Respiratory allergies caused by pollen have been on the rise in recent decades, and appear to be directly correlated with global warming.
Grasses are flowering herbaceous plants of the Poaceae family. Among the best known are:
- cereals – barley, wheat, oats or rye -,
- natural prairie grasses,
- and the cultivated lawn.
“Present throughout France, they pollinate from March to October with a peak in May and June” explains Dr Cottet. They are most often found in meadows, in forests or on the roadside.
The case of grasses
Grasses have a very strong allergenic potential.
“With climate change and the mild winters that we have had for several years, without frost or real cold, trees and plants are now pollinating earlier than before. This year, for example, the grasses pollinated from the end of February, ”adds the specialist.
“Ambrosia is a herbaceous plant mainly present in the Rhône Alpes region, which pollinates at the end of summer and beginning of autumn” describes the specialist. This plant, which spreads very quickly, has become widely established in France over the past 20 years.
Allergy to ragweed affects nearly 20% of the inhabitants of the Rhône valley, and 6 to 12% of the whole of France. Extremely allergenic, ambrosia can be responsible for severe allergy attacks, accompanied by asthma for one in two people on average.
Ragweed pollen is thorny and clings particularly well to clothing or animal hair: people with allergies should therefore be particularly vigilant when returning from a walk.
Cypress belongs to the cuppressaceae family, just like thuja and juniper. “Widely established in the south-east of France, around the Mediterranean, it is one of the rare trees to cause winter allergies” explains Dr Cottet. Its pollination period extends from November to March, with a peak in February, and cypress allergy is often mistaken for a winter cold.
Birch, like hazelnut or alder, belongs to the Betulaceae family. “Essentially present in the North of France, birch trees pollinate from February to May, with a peak in March and April” specifies the allergist.
Nearly one in two birch allergies also suffer from a cross-allergy to certain raw fruits and vegetables (apple, peach, pear, celery, carrot, etc.), and we also speak of “apple-birch syndrome”. Birch is one of the most allergenic trees there is, and it is also one of the most common in France, which explains the high prevalence of this allergy in France.
Symptoms of pollen allergies
The main symptoms
“The main symptoms of pollen allergies are ENT and lung” writes Dr Cottet. Patients allergic to pollen most often suffer from allergic rhinitis with sneezing, itching, runny nose, nasal obstruction, loss of smell, and conjunctivitis with a feeling of sand in the eye. This is commonly known as hay fever. There may be added cough and asthma with difficulty in breathing and wheezing.
“The allergenic protein of several pollens (PR10 and LTP) is also contained in many fruits (rosacea, nuts, exotic fruits …), allergic patients risk suffering from cross reactions to the ingestion of these foods” explains the allergist. The most common symptoms are most often simple itching of the mouth and palate, but they can go as far as anaphylactic shock.
Treatments for pollen allergies
As the allergist explains, “hygienic rules and symptomatic chemical treatments such as antihistamines, inhaled or nasal corticosteroids and eye drops provide relief but are not aetiological curative treatments”.
Desensitization: allergen immunotherapy
The only long-term treatment for allergies is allergen immunotherapy, also known as desensitization. “Recommended by the WHO, reimbursed by social security and mutual funds, it has been scientifically proven and allows a reduction or even disappearance of ENT and pulmonary symptoms, and a reduction or even the cessation of chemical symptomatic treatments. It also improves the symptoms of food cross reactions. »Describes Julien Cottet.
Desensitization to pollen is one of those that works best, and is said to be on average 70% effective.
How to limit exposure to pollen?
There are several tips to apply to limit exposure to pollen and reduce allergic risks. Here they are :
Air your interior
Air your interior for at least 10 minutes twice a day, in the morning before 9 a.m. and in the evening after 8 p.m. These hours are the coolest of the day and the pollen concentration is lower. The rest of the time, leave the windows closed.
Wear sunglasses – for those who don’t have glasses – to prevent pollens from settling on the conjunctiva and causing tearing and irritation.
Brush your clothes
Brush your clothes when you get home, to remove the pollens that have clung to them.
Shower every night
Shower every evening and wash your hair so as not to risk spreading pollens in your bed and on your pillow.
Tips for drying your laundry
Avoid drying your laundry outside.
Cleaning the nose
Cleanse your nose every evening with physiological serum.
Avoid mowing your lawn for people with grass allergies.