University of Iowa Health Science Relations and
John Weiler, MD
Professor Emeritus of Internal Medicine
Peer Review Status: Internally Peer Reviewed
It's August. Pity the poor ragweed allergy sufferers. For the next
six to eight weeks, they'll bear the marks of red runny noses, itchy
throats and ears, and watery eyes, says Dr. John Weiler, professor of
internal medicine at the University of Iowa College of Medicine. Only
an early frost will guarantee permanent relief from the bumper crop
of Iowa ragweed, but few Iowans are desperate enough to wish for an
Ragweed comes in two varieties, tall and short, and both release
pollen into the air at sunrise, says Weiler, also a staff physician
at UI Hospitals and Clinics. Ragweed plants throw more than 250,000
tons of pollen grains into the air. The pollen blows in the eastern
and central United States, making August and early September
miserable for many people. Most television weather forecasters report
pollen and mold counts during ragweed season. "You can listen to the
count to explain why you are so uncomfortable," says Weiler.
A pollen count up to 200 grains per day per cubic meter is called
the Comfort Zone. Most ragweed allergy-prone people will be
comfortable and free of allergy symptoms. The Discomfort Zone is
triggered when pollen counts rise from 200 to 1,000 grains of pollen,
and most ragweed allergy sufferers will probably have ragweed allergy
symptoms. A pollen count of more than 1,000 signals the Severe
Discomfort Zone, when most ragweed allergy sufferers will probably
have more severe symptoms. Even people who usually don't have
symptoms when the count is in the Discomfort Zone will have them
"Actual exposure to ragweed pollen will determine the severity of
symptoms a person will have during ragweed season. Even with a low
count, a farmer may be exposed to more pollen and have more severe
symptoms than an office worker who stays indoors during the height of
the pollen season," Weiler says.
"The pollen in the air triggers the body's immune system. When
pollen is inhaled, it attaches to a group of antibodies called IgE.
These antibodies are attached themselves to cells that release
histamine and other substances into the respiratory tissues. That's
when the wheezing and sneezing starts," Weiler says. If you have
asthma, and you inhale the airborne pollen, you may start coughing,
wheezing, and be short of breath.
"If you're allergic to ragweed, stay indoors in air-conditioned
areas, especially during morning hours. This will reduce your
symptoms," Weiler says. "The safest times to go outside are after a
rainfall or in the afternoon or evening."
If the symptoms are too irritating and making your life miserable,
your doctor may be able to prescribe a medication to relieve the
symptoms without causing side effects such as drowsiness.
For more information, contact your physician.
Division of Allergy and Pulmonary
Division of Immunology