Fueled by a warm, dry spring, the 2007 allergy season has turned into one of the nastiest in recent memory, according to physicians and scientists who track pollen levels in Maryland.
"It's definitely the worst I've ever seen," said Dr. David Golden, an allergist who keeps a pollen counter on the roof of his Owings Mills office to track day-to-day conditions for allergy sufferers.
The first week of May is always considered a bad stretch for people with seasonal allergies. Trees that began producing pollen in mid-April continue to spread their misery, while grass pollen adds to the mix in May.
"If you happen to have grass and tree allergies, this is a really bad time," said Dr. Martha White, a Wheaton allergist.
And here's more bad news: Things could get worse as the climate heats up.
Researchers have found evidence that a warming climate will enhance the growth of the pollen-producing trees and weeds that make people sick.
In a series of studies over the past decade, Lewis Ziska, a weed expert with the U.S. Agricultural Research Service in Beltsville, has found that oak trees and other pollen producers grow faster in urban settings where warmer temperatures, longer growing seasons and higher carbon dioxide levels mimic the conditions that experts predict will be widespread in coming decades.
Ziska found that oak trees and ragweed, both pollen producers, thrive in urban heat islands that are about 5 degrees Fahrenheit warmer than suburban and rural areas.
His findings, based on growth of trees and plants observed in Baltimore and Frederick County, are included in the International Panel on Climate Change report released last month.
The report, one of three released by the IPCC this year, examines the effects of climate change on health and the environment.
"Some of the plants we don't like may be the ones that do the best in a warmer world," said Jonathan Patz, a University of Wisconsin professor of environmental studies and an author of the IPCC report.
Too many variables are at work to definitively link climate change with an increase in the numbers of people getting sick, Ziska said. But he and other researchers say studies of recent growth patterns are intriguing.
"It's hard to say what the world is going to be like in 50 years - things change," Ziska said. "But what we see, in fact, could be a harbinger of things to come."
Seasonal allergies can strike at any age. About 19 million adults and 8 million children suffer from them, according to the federal Centers for Disease Control and Prevention.
Tree pollen peaks in late April and usually starts to drop by early May, while grass pollen peaks from late May to early June, said Susan Kosisky, who operates a pollen counter for the Army at the Walter Reed Army Medical Center annex in Silver Spring.
But this year, a spell of warm, dry weather led to some record-high tree pollen counts in April and kept the counts unusually high this month, until this week when levels started to drop, Golden said.
Pollen levels are measured by trapping and counting the number of grains per cubic meter of air.
At the Owings Mills station, Golden and his partner, Dr. Jonathan Matz, recorded 1,785 grains per cubic meter for the 24 hours that ended April 23 - the highest pollen level in his 11 years of counting, Golden said.
Allergists consider anything over 1,000 grains extremely high.
A pollen counter on the roof of the Walter Reed Army Medical Center annex in Silver Spring recorded 2,255 pollen grains April 23, said Kosisky, who is assistant chief of the allergen extract lab at Walter Reed. That's not an annex record, but it culminated four days of near record counts and prompted many patients to wonder what was causing their symptoms, she said.
"I've had patients calling, and I've got friends and family with allergies and they've been asking about the pollen this year," Kosisky said.
Counts from the Owings Mills and Silver Spring stations are reported to the American Academy of Allergy, Asthma and Immunology, and posted on the Web site of the organization's National Allergy Bureau. The Golden and Matz counts also are broadcast on area radio and television stations and published in The Sun.
Kosisky blamed the pollen levels on the warm, dry spring. "There were warm days, when it was in the 80s in April, and the trees just exploded with pollen," she said.
As a result, doctors say, they've been treating more allergy patients this year, often with more serious symptoms than in years past.
"I'm seeing people come in with more asthma, more eye symptoms and more rashes," said White, an allergist for 25 years. "This year ranks up there in the top 10 percent."
Skin rashes are a common symptom among children with seasonal allergies, she said. Many people have both asthma and seasonal allergies.
For patients with asthma, winter is worse than spring because asthma attacks can be triggered by cold weather and indoor allergens such as mold, White said. But among patients with asthma and allergies, pollen-induced respiratory problems can trigger asthma attacks if left untreated, she said.
"The lungs can be set off by a lot of things: cold air, cigarette smoke, exercise, respiratory infections and allergies," she said.
There is no one standard medication for seasonal allergies. Treatment options include nasal steroids, oral antihistamines and eyedrops. When those measures don't work, there are injections, which take four to seven months to become effective, White said.
The severity of this year's allergy season isn't news to Michelle Coble, a 40-year-old federal employee from Clinton whose allergies sent her to a specialist for the first time this spring.
Until this year, Coble used over-the-counter medications to battle the seasonal allergies she has suffered since childhood.
"Even as a child, I couldn't play in the grass," she said.
She saw White this spring after missing several days of work with migraine headaches, burning sinuses, sneezing and itchy eyes caused by her allergies.
A skin test revealed that she's is allergic to seasonal pollen, dust and dust mites. White prescribed a nasal spray and eyedrops.
Coble also plans to keep the windows closed in her car and house, limit her time outdoors, wash clothes in hot water to remove pollen and shop for a more powerful vacuum cleaner to snatch up the pollen and dust in her home.
If that isn't enough, she will get shots to cope with her allergies.
"The past three years, things have gotten worse," Coble said. "It's hard to get any work done if you're at home with your head in your hands."
For the latest pollen counts reported to the National Allergy Bureau, visit www.aaaai.org/nab/index.cfm?p=pollen
To minimize problems associated with seasonal allergies:
Limit outdoor activities when pollen counts are high. Peak pollen periods are usually 10 a.m. to 4 p.m.
Keep car windows closed when traveling.
Try to stay indoors when humidity is high and on windy days, when dust and pollen are blown about.
Use a surgical or painter's mask when gardening or working outdoors.
Shower after spending time outside - pollen can collect on skin and hair.
Keep windows closed at night. Air conditioning helps by filtering out pollen.
If sneezing, itching, headaches or other problems persist, consult an allergist, who can create a plan to manage symptoms and prescribe medications.
Sources: The American Academy of Allergy, Asthma and Immunology and Dr. Martha White