| Allergic
rhinitis is a collection of symptoms, predominantly in the
nose and eyes, caused by airborne particles of dust, dander,
or plant pollens in people who are allergic to these substances.
When these symptoms are caused by pollen,
the allergic rhinitis is commonly known as "hay fever".
Allergies are caused by an oversensitive
immune system, leading to a misdirected immune response. The
immune system normally protects the body against harmful substances
such as bacteria and viruses. Allergy occurs when the immune
system reacts to substances (allergens) that are generally
harmless and in most people do not cause an immune response.
As noted above, hay fever involves an allergic
reaction to pollen. A virtually identical reaction occurs
with allergy to mold, animal dander, dust, and similar inhaled
allergens.
The pollens that cause hay fever vary from
person to person and from region to region. Large, visible
pollens are seldom responsible for hay fever. Tiny, hard to
see pollens more often cause hay fever. Examples of plants
commonly responsible for hay fever include:
* Trees (deciduous and evergreen)
* Grasses
* Most flowers
* Ragweed
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.
Seriousness
of Allergy Rhinitis | Perennial
Allergic Rhinitis |
Relieving
Toddler Nasal Congestion |
Non-Allergic
Rhinitis| Causes
of Allergic rhinitis| Treatment
of Allergic rhinitis|
History
of Allergic rhinitis| Abnormal
production of nasal secretions|
Allergic
Rhinitis in Children|
How
can chronic rhinitis and post-nasal drip be treated?|
What
are rhinitis and post-nasal drip? |
