WASHINGTON — It’s prime time in in the D.C. area for ragweed.
The season began a few weeks ago and will hit its peak sometime around Labor Day, before ending with the first frost.
“Patients that have weed pollen allergy will suffer this time of year,” says Dr. Rachel Schreiber, an allergist in Rockville, Maryland.
Unlike many other plants that emit pollen in the spring and summer, ragweed waits until the days get shorter, starting to flower as the day length dips under 14 and a half hours.
Though ragweed starts emitting pollen in August — predominately in the Eastern and Midwestern states — allergists consider ragweed a fall allergen, along with mold and a slight uptick in grass pollen in autumn.
Someone who has trouble with ragweed will have typical allergy symptoms including itchy, watery eyes and a runny nose. “But the itching is the number-one symptom of allergy, and sometimes people just feel run down — they just don’t feel good,” says Schreiber.
Medications are available, both by prescription and over the counter. For really bad cases, immunotherapy, in the form of allergy shots or sublingual tablets, can build resistance to ragweed pollen.
The sublingual treatment was just approved last year by the U.S. Food and Drug Administration and is considered highly effective. However, it takes time to build up that resistance, and patients have to begin the process 12 weeks before ragweed season begins.
“So already for this season it is too late, but you could start it in the spring for next fall ragweed season,” Schreiber advises.
The Asthma and Allergy Foundation of America estimates that 10 to 20 percent of Americans suffer from ragweed allergy, or hay fever.
The ragweed plant usually grows in rural areas, and the grains of pollen travel through the air. Each plant lives only one season but each can produce 1 billion grains of pollen during its life span.