Pollen allergy: a modern plague
Pollen allergy is called hay fever. Generally cause allergies are those of anemophilous plants, their pollen is dispersed by air currents. Such plants produce large quantities of lightweight pollen, which can be carried for great distances and are easily inhaled, bringing it into contact with the sensitive nasal passages. Around world, about 5 %~10 % people fall in hay fever. Persons may suffer from an itching congested and running nose, a sore nasal-throat cavity, sneezing, caughing, watery and sometimes bloodshot eyes and also perhaps a light thightness of the chest. Other symptoms include: headache, fatigue, inflammation of sinuses and throat.
One does not become allergic for the entire pollen grains, but for certain proteins present in or around the pollen grains. These proteinscan been biochemically classified and get then a name composed from the first three letters ofthe genus of the plant which produces the pollen, followed by a number. The allergen Lol 1 is allergene nr 1 from the genus Lolium (Rye Grass). Sometimes also the first letter of the species is added to the name: Lol p 1 is allergene nr 1 from Lolium perenne (Perennial Ryegrass).
Pollen grains usually carry several allergens that each separately may cause symptoms. An allergic reaction to a certain allergen that also occurs after contact with an allergen from another source is also called cross-reaction. Who is sensitive to pollen belonging to a certain genus, for example Birch pollen, is more likely to suffer also from pollen of other groups belonging to the Birch family, like Alders and Hazels: they carry allergens that are quite similar. Cross-reactions can also occur between allergens from completely different origin, like Birch pollen, apples and nuts.
Allergies have complex reasons, in which both predisposition and environment play a role. Some persons may be predisposed to allergic reactions: allergies often “run” in certain families. The occurance of pollen (and other)allergies, is strongly enhanced by an unhealthy life style (e.g. smoking, consumption of alcohol and drugs) and air pollution (fine particles, nitrogen oxydes); but also an exaggerated hygiene during youth raises the risks to develop allergy, also being older. The nutritional pattern has possibly some effects as well. Regarding hay fever, the most evident remedial to prevent symptoms is to mind expose to the trigger, airborne pollen grains to which one is sensitive, by staying indoors or at least by refraining from having physical activity outside, especially on sunny and dry days. In this respect, pollen calendars provide a most useful indication. Wearing sun glasses, a hat and certainly a mask in extreme cases also helps.
