Fall Allergies Are Real. And They’re Getting Worse

Climate change is making this allergy season longer and more intense. Here’s how to cope.

Allergies don’t only crop up in the spring. The persistent sniffles, clogged nose, itchy eyes and sneezing also happen in the fall — and, experts say, they’re getting more common, and more intense.

“Everyone knows spring is the big one, but fall can be just as bad,” said Dr. Purvi Parikh, an allergist and immunologist at N.Y.U. Langone Health.

Here’s what to know about the seasonal surge in allergies, and how to handle it.

What causes fall allergies?

Ragweed, a tall, willowy plant that grows in cities and rural areas alike, is the most common culprit behind fall allergies, said Dr. Michele Pham, an allergist and immunologist at the University of California, San Francisco. Just one pesky plant can release one billion grains of pollen, she said, which can irritate and inflame our sinuses. Ragweed starts to bloom in August and typically peaks in mid-September, but it can continue to grow into November.

“Labor Day to the first good snow is weed season,” said Dr. Sandra Hong, an allergist at the Cleveland Clinic.

You can find ragweed in nearly every state in the country, Dr. Pham said, though it tends to grow in particularly great numbers on the East Coast and in the Midwest. Those with fall allergies can also blame the mold from leaves that fall and decay, which can stir up the same symptoms.

“What a lot of people don’t realize is that the allergy seasons have almost doubled in length and gotten more intense because of climate change,” said Kenneth Mendez, the president and chief executive of the Asthma and Allergy Foundation of America. Higher carbon dioxide emissions spur plants to release larger amounts of pollen, he said. “That’s why allergies are feeling a lot worse.”

And as temperatures stay warmer for longer periods of time and the first frost happens later and later, plants like ragweed have more time to grow and release allergens, Mr. Mendez said.

Cities tend to have higher temperatures than suburban or rural areas, as a result of the urban heat island effect, he said. Crammed buildings and infrastructure absorb and retain the sun’s heat, making it as much as seven degrees hotter in urban areas during the day, according to the Environmental Protection Agency. That means allergies may be particularly intense if you live in a city, Mr. Mendez said, where those warmer temperatures allow ragweed to grow for longer.

How to tell the difference between allergies, colds and Covid

Symptoms can vary from person to person, but many people will exhibit the same signs of allergies in the fall as they do in the spring, said Dr. Anju Peters, an allergist at Northwestern Medicine. That means runny noses, sneezing, stuffiness, postnasal drip and fatigue — symptoms that sound a whole lot like colds and Covid.

The only way to be completely sure you don’t have Covid is to take a test — but there are a few clues to help pin down the source of your sniffles.

Viral infections tend to develop suddenly, and then run their course, Dr. Parikh said, while allergies slog on for four or six or eight weeks at a time.

And allergies — unlike colds, Covid and the flu — don’t usually cause fevers, body aches or gastrointestinal symptoms like diarrhea, she said.

Itchiness can be a telltale sign that you’re dealing with allergies, so watch out for scratchy, tingling ears, eyes, throats and noses, she added. Fall allergens can also cause rashes like eczema.

It’s important to monitor your allergy symptoms, in particular because allergies can trigger asthma. More than 4,000 people die from asthma each year, Mr. Mendez said, and Black Americans are three times more likely to die from asthma and five times more likely to be treated for it in an emergency room. Black women have the highest rate of mortality from asthma in the United States, he added. Emergency room visits and hospitalizations related to asthma tend to rise in the fall, partly because of allergies, Dr. Parikh said; “people don’t realize how serious it is.”

Coughing, wheezing and chest tightness can be signs that an allergy has led to asthma, especially if you wake up in the middle of the night with these symptoms, Dr. Parikh said. If you feel winded, fatigued, or dizzy after mild physical activity, like household chores, or like you cannot complete your normal exercise routine, those may also be signs of the disease.

How to handle fall allergies

There are basic habits that can help mitigate the amount of pollen you track into your home. Keep your windows closed as much as possible, especially on sunny, windy days when pollen levels are particularly high, and remove your shoes at the door. You may also want to take a shower and change your clothes when you arrive home. HEPA air filters can help clean the air indoors and remove mold and dander. Try to vacuum your home more frequently, especially if you have pets, Dr. Hong said — daily if you can. Consider washing your sheets regularly as well, and if possible, keep your pets out of your bedroom, Dr. Hong said, so they don’t track pollen onto your pillow.

When you do go outside, you might want to wear a hat and sunglasses, Dr. Pham said, which can shield your face from pollen. (Masks may also mitigate symptoms.)

Medications are also a critical tool. Over-the-counter intranasal steroids like fluticasone and triamcinolone can help alleviate sniffling and congestion; eye drops can wash away irritants and treat symptoms like itchy, red, watery eyes. These targeted interventions tend to be more helpful than oral antihistamines, Dr. Pham said, although oral antihistamine tablets can also alleviate symptoms — particularly itching, sneezing and runny nose. (Think Allegra or Zyrtec.) Some oral antihistamines, like Benadryl, may make people drowsy.

Some patients may want to turn to decongestants, like Afrin or Sudafed, Dr. Parikh said, but those medications can have a “rebound effect” — after you take them for a prolonged period, blood vessels in your nose do not respond as well, and you can end up with even worse congestion. If you want to refrain from medication, nasal irrigators like neti pots can rinse pollen out of your sinuses, but they won’t treat the allergy itself, she said.

If allergy symptoms are interfering with your daily life, it may be time to see a doctor. Mr. Mendez recommends seeking a board-certified allergist, who can administer allergy testing and evaluation, like a skin-prick exam or blood test, to identify what types of pollen trigger your allergies. A doctor may recommend immunotherapy in the form of allergy injections that contain amounts of the allergens that you are allergic to, which can offer longer-term relief. Another option for those who don’t want to receive shots is sublingual immunotherapy: a tablet or wafer that melts under your tongue and fights against ragweed, dust mites and northern pasture grasses like timothy, Dr. Hong said. You can take the wafer once a day, and start using it before allergy season starts. Both forms of immunotherapy boost a patient’s tolerance to the allergy, which reduces symptoms.

“Every year,” Dr. Peters said, “everyone says: ‘This is the worst possible allergy season.’”

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