Seasonal allergic rhinitis,
often referred to as "hay fever," affects about 10~20%
of population throughout the world. These seasonal allergies
are caused by substances called allergens. Airborne
pollens and mold spores are outdoor allergens that commonly
trigger symptoms during the spring and fall. During
these times, seasonal allergic rhinitis sufferers experience
increased symptoms - sneezing, congestion, a runny nose,
and itchiness in the nose, roof of the mouth, throat,
eyes and ears-depending on where they live in the country
and the exact allergen to which they are allergic.What you have to
Pollens are the tiny, egg-shaped male cells of flowering
plants. These microscopic, powdery granules are necessary
for plant fertilization. The average pollen particle
is less than the width of an average human hair.
Pollens from plants with bright flowers, such as roses,
usually do not trigger allergies. These large, waxy
pollens are carried from plant to plant by bees and
other insects. On the other hand, many trees, grasses
and low-growing weeds have small, light, dry pollens
that are well-suited for dissemination by wind currents.
These are the pollens that trigger allergy symptoms.
In the temperate region, seasonal allergic rhinitis
in the early spring is often triggered by the pollens
of such trees as oak, western red cedar, elm, birch,
ash, hickory, poplar, sycamore, maple, cypress and walnut.
In the late spring and early summer, pollinating grasses
- including timothy, bermuda, orchard, sweet vernal,
red top and some blue grasses - often trigger symptoms.
In addition to ragweed - the pollen most responsible
for late summer and fall hay fever - other weeds can
trigger allergic rhinitis symptoms. These weeds include
sagebrush, pigweed, Japanese hop and goosefoot. Each
plant has a period of pollination that does not vary
greatly from year to year. However, weather conditions
can affect the amount of pollen in the air at any given
time in South Northern Asian countries such as Korea,
China, and Japan. The pollinating season starts later
in the spring. Tree pollinate earliest, from late February
through May, although this may fluctuate in different
locations - starting in April in the northern United
States to as early as January in the south. Grasses
follow next in the cycle, beginning pollination in May
and continuing until mid-July. Weeds usually pollinate
in late summer and early fall.
Molds are microscopic fungi - related to mushrooms -
but without stems, roots or leaves. Their spores float
in the air like pollen, and are present throughout the
year in many states. Unlike pollens, molds do not have
a specific season, but are affected by weather conditions
such as wind, rain or temperature.
Common airborne molds include alternaria, cladosporium
and aspergillus. Molds are present in almost every possible
habitat. Outdoors, they can be found in soil, vegetation
and rotting wood. Molds can also be found indoors in
attics, basements, bathrooms, refrigerators and other
food storage areas, garbage containers, carpets and
Pollen and mold counts
Pollen and mold counts measure the amount of airborne
allergens present in the air. Counts are compiled by
a variety of methods. Pollen and mold spore counts can
be determined daily, and are reported as grains per
cubic meter of air. Some countries like Korea have national
aeroallergen college counters throughout the country
and report the data weekly to the public.
Interpretation of pollen and mold counts and their relationship
to symptoms is complex. Sampling techniques such as
the type of device used and its location within the
community can affect counts. While many patients develop
symptoms when pollen counts are 20-100 grains per cubic
meter, one's symptoms may also be affected by recent
exposure to other allergens, the intensity of pollen
exposure, and individual sensitivity.
Effects of weather and location
Weather can influence hay fever symptoms. Allergy symptoms
are often minimal on days that are rainy, cloudy or
windless, because pollen does not move about during
these conditions. Hot, dry and windy weather signals
greater pollen and mold distribution and thus, increased
If you are allergic to plants in your area, you may
believe that moving to another area of the country with
different plants will help to lessen your symptoms.
However, moving to another part of the country to escape
allergies is often ultimately disappointing, and not
Appropriate treatment - not escape - is the best method
for coping with your allergies. If your seasonal allergy
symptoms are making you miserable, see your allergist/immunologist,
who will take a thorough history and conduct tests,
if needed, to determine exactly which pollens or molds
are triggering your symptoms. He or she will help you
determine when these airborne allergens are most prevalent
in your area. To lessen your symptoms, your allergist/immunologist
may also prescribe an allergy nose spray, non-sedating
antihistamine, decongestant or other medications.
If your symptoms continue or if you have them for many
months of the year, your allergist/immunologist may
also recommend immunotherapy treatment, also called
allergy vaccinations or shots. This treatment involves
receiving injections periodically - as determined by
your allergist/immunologist - over a period of three
to five years. This treatment helps your immune system
to become more and more resistant to the specific allergen,
and lessens your symptoms as well as the need for future
Tips for those who have allergen to pollen and mold
1. Keep windows closed at night to prevent pollens
or molds from drifting into your home. Instead, if
needed, use air conditioning, which cleans, cools,
and dries the air.
What you don't have to
2. Minimize early morning activity when pollen is
usually emitted-between 5-10 a.m.
3. Keep your car windows closed when traveling.
4. Try to stay indoors when the pollen count or humidity
is reported to be high, and on windy days when dust
and pollen are blown about.
5. Take medications prescribed by your doctor
regularly, in the recommended dosage.
1. Take more medication than recommended in an attempt
to lessen your symptoms.
2. Mow lawns or be around freshly cut grass; mowing
stirs up pollens and molds.
3. Rake leaves, as this also stirs up molds.
4. Hang sheets or clothing out to dry. Pollens and
molds may collect in them.
5. Grow too many, or overwater, indoor plants because
wet soil encourages mold growth.