What is Hay Fever? What is Rhinitis?
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Hay fever is an allergic reaction to pollen by Plato 18 year
Allergic rhinitis, also called pollinosis, hay fever or nasal allergies, is a collection of symptoms, predominantly in the nose and eyes, that occur after exposure to airborne particles of dust, dander, or the pollens of certain seasonal plants in people who are allergic to these substances.
When these symptoms are caused by pollens, the allergic rhinitis is commonly known as "hay fever", after the fact it is most prevalent during haying.
Allergy occurs when the immune system reacts to substances (allergens) that are generally harmless and in most people do not cause an immune response.
Hay fever involves an allergic reaction to pollen. A virtually identical reaction occurs with allergy to mold, animal dander, dust, and similar inhaled allergens. Particulate matter in polluted air and chemicals such as chlorine and detergents, which can normally be tolerated, can greatly aggravate the condition.
The pollens that cause hay fever vary from person to person and from region to region; generally speaking, the tiny, hardly visible pollens of wind-pollinated plants are the predominant culprits. Pollens of insect-pollinated plants are too large to remain airborne and pose no risk. Examples of plants commonly responsible for hay fever include:
Trees: such as birch (Betula), alder (Alnus), hazel (Corylus), hornbeam (Carpinus), horse chestnut (Aesculus), willow (Salix), poplar (Populus), plane (Platanus), linden/lime (Tilia) and olive (Olea). In northern latitudes birch is considered to be the most important allergenic tree pollen, with an estimated 15-20% of hay fever sufferers sensitive to birch pollen grains. Olive pollen is more important in Mediterranean regions.
Grasses (Family Poaceae): especially rye (Lolium sp.) and timothy (Phleum pratense). An estimated 90% of hay fever sufferers are allergic to grass pollen.
Weeds:ragweed (Ambrosia), plantain (Plantago), nettle/parietaria (Urticaceae), mugwort (Artemisia), Fat hen (Chenopodium) and sorrel/dock (Rumex)
In addition to individual sensitivity and geographic differences in local plant populations, the amount of pollen in the air can be a factor in whether hay fever symptoms develop. Hot, dry, windy days are more likely to have increased amounts of pollen in the air than cool, damp, rainy days when most pollen is washed to the ground.
When an allergen such as pollen or dust is inhaled by a person with a sensitized immune system, it triggers antibody production. These antibodies bind to cells that contain histamine. When the antibodies are stimulated by pollen and dust, histamine (and other chemicals) are released. This causes itching, swelling, and mucus production. Symptoms vary in severity from person to person. Very sensitive individuals can experience hives or other rashes.
Some disorders may be associated with allergies. These include eczema and asthma, among others.
Allergies are common. Heredity and environmental exposures may contribute to a predisposition to allergies.
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Allergic rhinitis, also called pollinosis, hay fever or nasal allergies, is a collection of symptoms, predominantly in the nose and eyes, that occur after exposure to airborne particles of dust, dander, or the pollens of certain seasonal plants in people who are allergic to these substances.
When these symptoms are caused by pollens, the allergic rhinitis is commonly known as "hay fever", after the fact it is most prevalent during haying.
Allergy occurs when the immune system reacts to substances (allergens) that are generally harmless and in most people do not cause an immune response.
Hay fever involves an allergic reaction to pollen. A virtually identical reaction occurs with allergy to mold, animal dander, dust, and similar inhaled allergens. Particulate matter in polluted air and chemicals such as chlorine and detergents, which can normally be tolerated, can greatly aggravate the condition.
The pollens that cause hay fever vary from person to person and from region to region; generally speaking, the tiny, hardly visible pollens of wind-pollinated plants are the predominant culprits. Pollens of insect-pollinated plants are too large to remain airborne and pose no risk. Examples of plants commonly responsible for hay fever include:
Trees: such as birch (Betula), alder (Alnus), hazel (Corylus), hornbeam (Carpinus), horse chestnut (Aesculus), willow (Salix), poplar (Populus), plane (Platanus), linden/lime (Tilia) and olive (Olea). In northern latitudes birch is considered to be the most important allergenic tree pollen, with an estimated 15-20% of hay fever sufferers sensitive to birch pollen grains. Olive pollen is more important in Mediterranean regions.
Grasses (Family Poaceae): especially rye (Lolium sp.) and timothy (Phleum pratense). An estimated 90% of hay fever sufferers are allergic to grass pollen.
Weeds:ragweed (Ambrosia), plantain (Plantago), nettle/parietaria (Urticaceae), mugwort (Artemisia), Fat hen (Chenopodium) and sorrel/dock (Rumex)
In addition to individual sensitivity and geographic differences in local plant populations, the amount of pollen in the air can be a factor in whether hay fever symptoms develop. Hot, dry, windy days are more likely to have increased amounts of pollen in the air than cool, damp, rainy days when most pollen is washed to the ground.
When an allergen such as pollen or dust is inhaled by a person with a sensitized immune system, it triggers antibody production. These antibodies bind to cells that contain histamine. When the antibodies are stimulated by pollen and dust, histamine (and other chemicals) are released. This causes itching, swelling, and mucus production. Symptoms vary in severity from person to person. Very sensitive individuals can experience hives or other rashes.
Some disorders may be associated with allergies. These include eczema and asthma, among others.
Allergies are common. Heredity and environmental exposures may contribute to a predisposition to allergies.
Viewed 5228 times
All Plato's Answers