Allergy and the Body's Allergic Reaction
What is Pollen?
Pollen are male cells from flowering plants. The cells, taking
the shape of a powdery substance, help plant fertilization.
The large, waxy pollen
from plants with bright flowers, such as roses, don’t usually
aggravate allergies. They are too heavy to be carried by the
wind and thus have to rely on bees and other
insects to carry pollen from plant to plant.
Those plants that have small, light, dry pollen include many trees,
grasses, and low-growing weeds. Their pollen is perfect for dissemination
by wind and is the pollen that usually triggers allergic reactions.
To find out the amount of airborne allergens present in the air,
pollen counts are compiled. Several methods can be used to count
the pollen in the air including certified aeroallergen counters
at universities, medical centers and medical clinics.
According to the American Academy of Allergy Asthma and Immunology,
pollen counting stations usually start reporting on pollen levels
in March and April because this is when pollen levels increase
to measurable amounts. The date can vary from station to station
each year based on local weather conditions. Those pollen counting
stations that are located in warmer climates generally stay open
Weather Affects Pollen Allergy
Rainy, cloudy, or windless days usually produce less pollen in
the air because the pollen does not flow freely through the air.
For hay fever sufferers this type of day would be best if needed
to spend time outside. The worst days for hay fever sufferers
are hot, dry, windy days. With the hot, dry wind there is greater
pollen and mold distribution, increasing allergy symptoms.
The beginning and end
times of various plant’s pollen seasons
remain very similar from year to year in the same location but
intensity of pollen in the air can differ based on the pervious
year’s weather, current weather, and extreme environmental
Not only does the weather and season affect pollen levels, the
amount of pollen in the air can also vary depending on the time
of day. Pollen is usually at its highest concentration between
5 and 10 a.m.
The Allergic Reaction Caused by Pollen Allergy
The immune system’s normal function is to defend against
germs, bacteria, and viruses that could harm the body. When a person
has an allergic reaction, the immune system is having the same
defense response to a non-threatening substance. The immune system
sees the allergen the same way it would see a germ and works to
The NIAID explains the
immune system’s way of attacking
“The immune system
does this by generating large amounts of a type of antibody called
immunoglobulin E, or IgE. Each IgE
antibody is specific for one particular substance. In the case
of pollen allergy, each antibody is specific for one type of pollen.
For example, the immune system may produce one type of antibody
to react against oak pollen and another against ragweed pollen.
The IgE molecules are
special because IgE is the only type of antibody that attaches
tightly to the body’s mast cells,
which are tissue cells, and to basophils, which are blood cells.
When the allergen next encounters its specific IgE, it attaches
to the antibody like a key fitting into a lock. This action signals
the cell to which the IgE is attached to release (and, in some
cases, produce) powerful chemicals like histamine, which cause
inflammation. These chemicals act on tissues in various parts of
the body, such as the respiratory system, and cause the symptoms
If a person has an allergy to pollen, large amounts of IgE are
produced in the body when that person comes into contact with pollen,
usually by inhalation of pollen granules. A pollen allergy sufferer
can usually find relief through antihistamines and prevention strategies
such as staying indoors on high pollen count days.
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