HealthDay News – This winter’s polar vortex has caused overlapping allergy seasons this year, according to researchers.

This longer and colder winter kept trees dormant for longer than usual, which means tree pollen season will coincide with grass pollen and mold seasons this year, increasing the reactions for patients who have multiple environmental allergies.

In order to measure pollen levels for the National Allergy Bureau, Joseph Leija, MD starts measuring pollen counts in the Chicago area in February, when tree pollen usually starts. This year, however, “the pollens [are] all coming in at the same time,” said Leija. “The season will probably be shorter, but people with allergies will be more miserable.”

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Tree season started later in other areas of the country, too, noted Robert Valet, MD, from Vanderbilt University. “The grass season seems to be moving along normally,” said Valet, “so the seasons are less discrete and might be harder to separate this year.”

Both Leija and Valet recommend patients start a preventative allergy medication regimen, stating that nasal steroids take about two weeks to reach their peak effectiveness.


1.     Gordon, Serena. (25 April 2014). Winter’s Polar Vortex Ushers in Spring’s ‘Pollen Vortex’. HealthDay. Retrieved from: