Invasive ragweed is nothing to sneeze at

September 02, 1997|By Anthony R. Wood | Anthony R. Wood,KNIGHT-RIDDER NEWS SERVICE

PHILADELPHIA -- Michelle Robertson assumed it was a nasty cold that kept showing up every year around this time. She had days when she would sneeze her head off. She had trouble driving.

She missed time from her job as a medical assistant at a doctor's office, and when she did show up, the patients would look at her red, swollen eyes and give her friendly advice: See a doctor.

She did. "I just couldn't take it anymore," said Robertson, 25. She learned that, like about 20 percent of the population, she was allergic to pollen. In her case, it was ragweed pollen, the king of the allergens, which is about to assert its annual reign.

Allergists such as Marc Goldstein are expecting a busy season. Around Philadelphia he has noticed a bumper crop of the scrawny green weeds popping through sidewalk cracks, poking through blacktop crevices and blanketing vacant lots.

As the name implies, ragweeds are homely, gritty wildflowers. They resemble drought-withered tomato plants, and they are ubiquitous (pollen grains have been found in Antarctica). And while they are not much to look at, this time of year they pollinate their brains out.

Ragweed is the cockroach of the plant world; it can thrive almost anywhere on almost anything. "It's not as temperamental as other flowers," said Goldstein, a specialist at an asthma center. "It's a hardy, hardy plant. It really lives in very coarse conditions."

Like the plant, the grains aren't terribly attractive. In diameter, they are all of 1/25,000th of an inch, or about the size of your last pay raise. Magnified, the spiked, spherical grains look amazingly like a land mine.

And for pollen sufferers, they hit about as hard.

Among all the pollen allergens, including trees and grasses, ragweed affects the most people, said Sarah Krukowski, manager of the National Allergy Bureau for the American Academy of Allergy, Asthma and Immunology.

It is estimated that 250,000 tons of ragweed pollen fill the air over the United States every year, and pollen has been found hundreds of miles from its source.

While it is impossible to predict how severe a given ragweed season will be, researchers are working on ragweed-forecast models, said Harriett Burge, a professor of environmental microbiology at Harvard University.

The pollen is measured by a Rotorod, something akin to a high-tech roach motel. The pollen is trapped on rotating greased rods that sample the air every 10 minutes. The pollen counts represent how many grains would fill a cubic meter of air over a 24-hour period.

Pollen counts below 10 are considered low, but even at low levels they can affect hypersensitive allergy patients. Counts above 60 can bring on severe symptoms. In recent years, counts around here have approached 400 during the second week of September.

The most common symptoms, of course, are sneezing, red and itchy eyes, scratchy throat and runny nose. Save for the discomfort, not to mention a serious slippage in social graces, in most cases the symptoms are harmless, notes Eileen Haralabatos, an allergy specialist with the Hospital of the University of Pennsylvania.

However, they can cause chest tightness, shortness of breath and wheezing among asthma sufferers, and can lead to middle-ear infections. Allergic reactions can lead to sinus infections and bronchitis.

The pollen count is a useful indicator, but allergists advise symptoms can be extreme on low-count days and negligible on high-count days.

Pollen has a cumulative effect. Exposure early in the season in effect wears down resistance to pollen -- and to other irritants.

"It's particularly true as we get further along in the season, where it takes less pollen to induce symptoms. Once your lung and pulmonary respiratory membranes are inflamed, they are more likely to respond to nonspecific irritants.

"It's kind of a vicious cycle."

Something unrelated to ragweed, such as cigarette smoke, can trigger a pollen-type reaction, said Joel Eisner, a Philadelphia-area allergist.

Richard Dieterle, 47, a banker, said his symptoms have kicked in when his home-heating system went on for the first time after the weather cooled down.

In some cases, Goldstein said, honeydew, cantaloupe and watermelon, which are related to the ragweed plant, can cause mouth irritations among the ragweed-sensitive.

The far more typical reaction, however, is sneezing, which is the body's way of saying "get out of here." Sneezing is the result of a complex dance between the pollen and the body's immune system -- but only in those who are allergic. For them, "it's a maladaptive response," said David Lang, chief allergist at Allegheny University Hospitals. For others, the offending pollen is harmless.

Allergists advise that the best strategy for pollen sufferers is to avoid contact with the tormentor.

Since avoiding all pollen contact is virtually impossible, they recommend staying inside as much as possible and keeping the windows closed.

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