- Researchers say climate change is causing allergy seasons to start earlier in the spring as well as the summer and fall.
- They say longer allergy seasons create longer periods of allergic reaction and increase medical costs.
- Experts say the best way to lessen allergic reactions is to avoid places where pollen is in the air.
Pollen season is starting earlier and lasting longer thanks to climate change, and experts say it could be problematic for people who have allergies.
Research conducted in Germany and published this week in the journal Frontiers in Allergy found that certain pollen species are beginning their seasons as many as two days earlier each year over a 30-year period.
It’s the latest in a long line of research that suggests pollen season is lengthening, with some studies suggesting pollen season in the United States and Canada has been extended by up to 20 days in the past 30 years.
“The seasons are definitely longer,” Dr. Rita Kachru, an allergy specialist at UCLA Health in California, told Healthline.
“(Spring pollen season) used to start in March, now we’re finding it’s starting in mid-February, and it can go all the way to May. That spring season, which is predominantly tree pollen, often will go even longer. It’ll go to even early June,” she said.
It’s not only spring pollen season that is extending. Kachru says similar trends are being seen at other times of the year.
“Grass season or summer season used to start in May, and now we’re seeing it starting as early as April, and it used to end sometime in August, and we’re seeing it ending early September,” she said. “Fall season, which is predominantly weeds and outdoor mold, used to be predominantly starting in August till late November, and now we’re seeing it start in August but going toward more mid-December.”
Pollen grains are scattered from flowering plants, grass, trees, and weeds.
The allergens then spread through the air, causing problems for those who have allergies.
According to the U.S. Centers for Disease Control and Prevention (CDC), up to
“Climate change will potentially lead to shifts in precipitation patterns, more frost-free days, warmer seasonal air temperatures, and more carbon dioxide (CO2) in the atmosphere,” the CDC states.
“These changes can affect: when the pollen season starts and ends and how long it lasts each year, how much pollen plants create and how much is in the air, how pollen affects our health (the “allergenicity” of pollen), how much pollen we’re exposed to, and our risk of experiencing allergy symptoms,” the agency adds.
Pollen exposure can trigger a variety of allergic reactions.
“When we breathe in pollen, if you’re allergic it would be recognized by our antibodies, and those antibodies will trigger cells in our bodies to release chemical mediators, which lead to inflammation. The most common of these mediators is histamine, and the histamine leads to the symptoms of the itching, the watery eyes, the runny nose, the sneezing, and the coughing that people have,” Dr. Elisabeth D. Ference, an otolaryngologist at Keck Medicine of USC in California, told Healthline.
“The things that people should look out for for pollen allergies are itching eyes, itching nose, sneezing, eye redness, cough, itching in the throat, itching ears… postnasal drainage or nasal drip from their nose,” she added. “They should seek out medical help whenever they feel that their symptoms are severely affecting their quality of life or if they don’t respond to typical treatment such as over-the-counter antihistamine medications or over-the-counter nasal steroid spray.”
Tonya Winders, CEO of the Allergy & Asthma Network, says any allergy symptoms should be taken seriously.
“It can be quite debilitating and even dangerous, especially if people suffer from asthma attacks as a result,” she told Healthline.
Those experiencing allergies have a few options to avoid or combat symptoms: avoidance, medications, and immunotherapy.
“I’m a big proponent of avoidance because we know that if you can avoid the allergen, you’re actually decreasing your inflammatory reaction from even starting,” Kachru said.
Dr. Marissa A. Love, an allergy and immunology specialist at the University of Kansas Health System, had similar advice.
“Learning what allergens cause the person’s symptoms is helpful so they can try to avoid them,” she told Healthline. “Monitoring the daily pollen counts is also helpful. When the pollen counts are high, you can minimize your exposure by closing the windows, minimizing time outside, or taking a shower after being outdoors.”
There are other options for those experiencing allergy symptoms.
“There are steroid nasal sprays, antihistamine nasal sprays, saline nasal rinses, oral antihistamines, and oral decongestants,” Love added. “There are also prescription medications that can be used. It does help to start these medications before the season gets underway.”
During COVID-19, mask use has meant some people experienced fewer symptoms from pollen allergies than they used to, Ference says.
“Masks that have filtration levels that can catch the small particles like pollen can help prevent against the inhalation of pollen,” he said. “You just have to make sure that your mask is clean.”
Every year, medical costs associated with pollen
“Higher pollen concentrations and longer pollen seasons can also make you more sensitive to allergens. This can trigger asthma episodes in individuals with asthma and diminish productive work and school days,” the CDC states.
Ference says the lengthening of allergy seasons may not only mean longer periods being symptomatic for people, but may also call for changes to treatment schedules.
“There are treatments available which can help prevent symptoms. These treatments work better if started a few weeks before allergy symptoms begin for seasonal pollen allergies,” she said.
“So if this study is true, not only in Germany but also in California, then people might need to start treatments for allergies to tree pollen a few weeks earlier over time compared to when they are currently started,” Ference added.