Climate change causing longer, more severe allergy seasons

A branch with blooming flowers and pollen in the sun

For many, warmer weather signals the beginning of a months-long battle against the puffy eyes, runny noses and headaches that often accompany seasonal allergies. Recent warmer winters and earlier starts to the blooming trees and plants of springtime means symptoms begin sooner and last longer.

And for countless years, that was the case for Michaela Martin, an allergy patient at The Ohio State University Wexner Medical Center.

“I definitely noticed my allergies change when the seasons either come earlier or we have a little bit of a surprise spring, then go back to winter and then back to spring again,” Martin says.

Allergy experts at The Ohio State University Wexner Medical Center attribute these changes to the warming climate and increased carbon dioxide levels in urban areas, leading to longer pollen seasons and higher pollen counts.

“Allergy seasons have been changing in North America and across the globe, and we see greater changes the further you get from the equator,” says Kara Wada, MD, an allergist immunologist at the Ohio State Wexner Medical Center and a clinical assistant professor of allergy and immunology at The Ohio State University College of Medicine. “In the United States, the time between our thaw and our freeze is much longer, so plants have longer to reproduce and produce more pollen.”

Not only do these environmental changes impact long-time allergy sufferers, but it has also led to a growing number of people being diagnosed with seasonal allergies for the first time. According to the U.S. Centers for Disease Control and Prevention, 19.2 million adults were diagnosed with seasonal allergies in 2018, the most recent year of data available. Seasonal allergies are the sixth leading cause of chronic illness in the U.S. and affect up to 60 million people.

With the increase in irritants in the air, Dr. Wada recommends allergy testing to determine which allergens are causing the symptoms. Once allergy testing is complete, she advises her patients take a three-prong approach to treatment:

  • Avoidance: Monitor pollen levels and avoid spending time outdoors when pollen counts are high. If you must spend time outdoors, when you return home, change your clothes and bathe to remove pollen from your skin and hair. Keep windows closed in the car and at home. Use high-efficiency filters in your heating and cooling system and change them regularly.
  • Medication: If possible, begin taking antihistamines recommended by your doctor a few weeks before spring allergy season begins. Taking medication early can stop the body’s histamine response before it starts. Histamine causes the inflammation that leads to itchy eyes, nasal congestion and sneezing. It can be hard to stop the body’s histamine response once it starts.
  • Immunotherapy: Given over a three-to-five-year period, immunotherapy can desensitize the immune system to the allergen. Small doses of the allergen are given in shots, drops or tablets placed under the tongue to slowly retrain the immune system not to react to it. Once immunotherapy is complete, patients may need little to no allergy medication.

“There are incredibly helpful, really effective treatments that an allergist immunologist can help you figure out the perfect combination to help treat your symptoms and get you feeling better,” Dr. Wada says. “If allergies go untreated, not only are your symptoms going to worsen with stuffy nose and sneezing, but that also can sometimes progress into sinus infections, and recurrent sinus infections can sometimes require surgery.”

Martin says this approach improved her quality of life.

“Now I just take a daily over the counter medication and live symptom free, pretty much, with my allergies,” Martin says. “You'll find yourself not modifying your day-to-day or your routine or opting out of social events or other activities due to your allergies.”

Scientists continue to identify new allergens. More than 100 new allergens have been named in the past three years, including common seasonal insects that invade our homes, like the Asian ladybug. This research helps allergy sufferers take action against exactly what’s causing their symptoms.

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