Weed Pollens
As you drive down the highway in late summer or early fall, past wildflowers, grasses, and weeds, it may not occur to you that lurking among the vegetation may be the most potent and widespread cause of allergy symptoms.
Ragweeds
Ragweed, a tall, branched plant, is native to North America and found throughout the lower 48 states on dry fields, pastures, roadsides, and construction sites.
- Ragweed has 17 different species throughout the United States.
- The plants usually release pollen between mid-July and September for 4 to 6 weeks.
- The amount of pollen increases with heavy spring rainfall and a hot, dry summer and decreases with a wet or humid summer.
- Ragweed pollen is so small it can enter your home through tiny cracks. And, of course, it pours in whenever the doors or windows open.
- One plant can generate 1 billion grains; counts as low as 20 grains per cubic meter of air—fewer than 1,000 grains in your entire bedroom—can trigger an allergic reaction.
- The ragweed/composite family includes marsh-elder, cocklebur, groundsel-bush, desert broom, feverfew, sunflower seeds, dog fennel, chamomile, chrysanthemum, and marigolds.
Sagebrush
Sagebrush, another member of the ragweed family, blooms from July to late September and is often found in the western states. The wormwoods and mugwort, prevalent in the central states, produce pollen in the late summer and fall.
Dock
As a general rule, weeds usually release pollen from late spring until the first frost of fall. Members of the Dock family—including sheep sorrel, curly dock, and buckwheat—are found throughout the United States and bloom from May to September.
English plantain
English plantain, a particularly allergenic member of the plantain family, blooms during the grass season from May until November.
Pigweeds
Pigweeds and goosefoots grow well in soils that are disturbed by farming or traffic. They typically bloom from June to October, but may start as early as April in the southern states. Some of the most allergenic pigweeds are the southern water hemp, redroot pigweed, common pigweed, Palmer's amaranth, and western water hemp. The closely related goosefoots include lamb's-quarter, Mexican tea, and tumbleweed—which bloom from July to October.
Other weed allergens
Burning bush, smother weed, greasewood, barilla, saltbushes, scales, orachs, spearscale, glasswort, sea blite, saltwort, sugar beet, dog fennel, hemp, hop, castor bean plant, three-seeded mercury.
Other allergens: Trees and grasses.
CLARINEX®, a prescription medication, treats year-round allergy symptoms and ongoing hives of unknown cause, in adults and children 6 months and older, and seasonal allergy symptoms in patients 2 years and older. CLARINEX® 5 mg Tablets and 5 mg RediTabs® Tablets are approved for patients 12 years and older; CLARINEX® 2.5 mg RediTabs® Tablets are approved for patients 6 to 11 years; CLARINEX® Syrup is approved for patients 6 months and older.
Twice-daily CLARINEX-D® 12 HOUR Extended Release Tablets and once-daily CLARINEX-D® 24 HOUR Extended Release Tablets treat the symptoms of seasonal allergies, including nasal congestion, in patients 12 years and older.
IMPORTANT SAFETY INFORMATION
CLARINEX® Tablets side effects in patients 12 years and older were similar to placebo and included sore throat, dry mouth, and fatigue for seasonal and year-round allergy patients, and headache, nausea, and fatigue for patients with ongoing hives of unknown cause.
CLARINEX® Syrup side effects in children 6 to 11 years were similar to placebo. For children 6 months to 5 years, syrup side effects varied by age and included fever, diarrhea, upper respiratory infection, irritability, and coughing.
Due to their pseudoephedrine component, CLARINEX-D® 12 HOUR Extended Release Tablets and CLARINEX-D® 24 HOUR Extended Release Tablets should not be taken by patients with narrow-angle glaucoma (abnormally high eye pressure), difficulty urinating, severe high blood pressure, or severe heart disease, or by patients who have taken a monoamine oxidase (MAO) inhibitor within the past fourteen (14) days. Patients with high blood pressure; diabetes; heart disease; increased intraocular pressure (eye pressure); thyroid, liver or kidney problems; or enlarged prostate should check with their healthcare provider before taking CLARINEX-D® 12 HOUR Extended Release Tablets or CLARINEX-D® 24 HOUR Extended Release Tablets.
Care should be used if CLARINEX-D® 12 HOUR Extended Release Tablets or CLARINEX-D® 24 HOUR Extended Release Tablets are taken with other antihistamines or decongestants because combined effects on the cardiovascular system may be harmful. The most commonly reported adverse events for CLARINEX-D® 12 HOUR Extended Release Tablets were insomnia, headache, dry mouth, fatigue, drowsiness, sore throat, and dizziness. The most commonly reported adverse events for CLARINEX-D® 24 HOUR Extended Release Tablets were dry mouth, headache, insomnia, fatigue, sore throat, and drowsiness.
Click here for important CLARINEX® Tablets/Syrup/RediTabs® Product Information.
Click here for important CLARINEX-D® 12 HOUR Product Information.
Click here for important CLARINEX-D® 24 HOUR Product Information.
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.
Note: The information on this site is not intended to be a substitute for professional medical advice. If you have any questions about your treatment or medical condition, please consult your doctor or other qualified health care provider. This site is intended for use by U.S. residents.
