Ragweed season is peaking in the Philly region. Don’t confuse allergy symptoms with COVID-19.

Ida's rains likely offered one consolation prize: It held down the ragweed pollen. That won't last.

Meet the common ragweed, a tormentor of millions.Read moreWikimedia Commons

Published Sept. 6, 2021, 5:12 a.m. ET

This has been quite a delightful summer, at least for the average ragweed plant.

Chances are excellent that those hearty weeds are going to be celebrating the next couple of weeks with outbursts of reproductive pollen to torment millions of allergy sufferers in the Philly region and across the country.

In purely coincidental sync with the hurricane season, this is the peak period for the ragweeds. Last week’s rains likely suppressed the daily pollen output: Rainfall dampens the flight plans. But plenty more is on the runways.

Unfortunately, that benign effect — and that would be the only one related to Ida — tends to evaporate after 48 hours, said Donald Dvorin, an allergist who is the region’s certified National Allergy Bureau pollen counter.

So expect a harvest on dry days this week. “It’s coming,” Dvorin said.

The season typically noses into October. These days, however, thanks to increases in carbon dioxide and the associated rise in global and local temperatures that has nudged back those first-frost dates, it appears to be lasting a little longer, says Melanie Carver, chief mission officer with the Asthma and Allergy Foundation of America.

Predicting specifically just how bad the season will be remains problematical, said Dvorin, with last year being a case in point.

However, if you are allergic to ragweed, this is not necessarily the best time to be spending a lot of time outside. Among the nation’s 100 most populous regions, Philadelphia ranks in the top 30 “most challenging” places to live for the allergic, based on pollen levels and treatment options, the foundation says.

What is ragweed?

Ragweed might sound like a pejorative moniker, and in this case it is wholly merited. Pollen is part of the plant’s reproductive process; so they must see something in each other.

It is homely, hearty, and ubiquitous. The only refuge in the United States would be Alaska, according to the allergy foundation.

It comes in 50 different species, said Marc Goldstein, allergist at the Asthma Center in Philadelphia, and one plant can manufacture a billion pollen grains.

It is a trigger of the sneezing, itchy eyes, and decided dopiness that are common symptoms of “hay fever,” which has absolutely nothing do with hay.

The American Academy of Allergy, Asthma & Immunology identifies the most significant tormentor as the tooth-leaved ragweed that resides low in grasses.

COVID-19 vs. ragweed

Some symptoms of COVID-19 and seasonal allergies can overlap, doctors advise, among them coughing, fatigue, headache, and a loss of smell.

However, allergies are not associated with fevers, chills, sore throats, muscle pain, or intestinal problems.

Here is a handy chart courtesy of the Asthma Center.

Keeping counts

The tormented would be wise to track the daily pollen counts.

They are posted between 6 and 7 a.m. by Center City’s Asthma Center, which uses an automated system. Later in the day Dvorin, whose practice is in Mount Laurel, posts counts based on a 24-hour sample of what has been captured in his pollen traps.

While the counts aren’t predictive, they can give you some idea of what you’re in for. Actual pollen forecasting remains a work in progress.

Dvorin said a key factor in the intensity of the season would be rainfall six weeks before the season, which usually starts in mid-August. Conditions appeared ripe for a robust season last year, he said, but only on a few days did the counts reach extreme levels.

Any showers could affect pollen levels this week; however, inevitably ragweed will have its days. And those days appear to be extending their reach.

Some evidence suggests lengthening seasons, said Dvorin, although data are wanting, and for a variety of reasons fewer allergists are participating in the counting network.

That would be tied to generally warmer falls. An Inquirer study documented that in the first 18 years of the 21st century, Philadelphia’s first official freeze — defined as the first day that the temperature dropped to 32 degrees — on average was arriving on Nov. 14, six days later than it was in the period from 1874 to 2000.

In addition, the allergy foundation’s Carver said, all that carbon dioxide might be supplying vitamins to the plants to make them more productive. Just what allergy sufferers needed.

What’s to be done?

Aside from shots and medications, allergists say the best strategy for avoiding symptoms is simply avoiding pollen.

If outside, change clothes when you go back inside, and keep the windows clean if you can stand it.

Masks can help, but Goldstein advises that they are also pollen traps, so it wouldn’t hurt to wear a washable outer mask and keep the inner one in a clean plastic bag.

And the season will end, although these days it just might take a little longer.