Spring is here — and if you’re among the estimated one in four adults in the United States who suffer from seasonal allergies, your sneezing and scratching may have already started.
With climate change affecting temperatures and plant growth, you may need to be on the lookout earlier than ever before. It can be hard to distinguish allergy symptoms from those of a cold, but experts point to a few telltale signs.
Is allergy season getting worse?
Spring allergy seasons are beginning about 20 days earlier than they had, according to an analysis of pollen count data from 60 stations across North America from 1990 to 2018.
That shift can have significant health consequences, said William Anderegg, who is an author of the study and an associate professor of biology at the University of Utah. Other research has shown that very early onset of spring is associated with higher prevalence of allergic rhinitis, also known as hay fever. When people end up sick or in the hospital from uncontrolled allergy symptoms, he said, “it’s because they didn’t expect it, and didn’t have medications in hand.”
The researchers also found that pollen concentrations have risen about 20 percent nationwide since 1990, with Texas and the Midwest having the greatest increases. Warmer temperatures, higher concentrations of carbon dioxide and increased precipitation can all contribute to plants’ growing bigger and producing more pollen over longer periods of time, Dr. Anderegg said.
Dr. Gailen Marshall, chair of the allergy and immunology department at the University of Mississippi Medical Center, said that when he began practicing nearly 40 years ago, allergy seasons were confined to about eight weeks each. Tree pollen hit in the spring, grass pollen increased in spring and summer and ragweed pollen picked up in late summer and early fall.
Back then, people “could at least get some relief” between those cycles, said Dr. Marshall, who is also president of the American College of Allergy, Asthma and Immunology, a professional organization. “Now, these seasons end up becoming one long season.”
How can you tell whether it’s allergies or a cold?
Many people with nasal congestion or a runny nose may assume that they have a cold. Though allergy and cold symptoms can be similar, allergies often make the eyes, nose, throat, mouth or ears itchy, said Dr. Rita Kachru, chief of clinical allergy and immunology at UCLA Health. With allergies, the immune system mistakes a trigger, like pollen, for a harmful substance. When repeatedly exposed to that trigger, Dr. Kachru said, immune cells release chemicals, including histamine, that cause itchiness and inflammation.
Patients also often experience congestion and postnasal drip, or mucus dripping down the back of the throat. Some people may develop coughing, wheezing and shortness of breath.
With a viral infection, by contrast, you might have muscle fatigue, joint aches or a fever.
If your symptoms flare up every year around a certain season and last more than a week or two, then there is a good chance they’re being caused by allergies. A personal or family history of allergies, eczema or asthma can also be an important clue, doctors said.
What if I’ve never had allergies before?
Most people first develop symptoms in childhood or young adulthood. But several experts said it’s not uncommon for someone to have seasonal allergies for the first time as an adult.
Moving to a different part of the country and being exposed to different allergens may provoke a response, Dr. Kachru said.
New allergy symptoms in adulthood could also be “an inevitable consequence of really soaring pollen counts,” said Dr. Neeta Ogden, a New Jersey-based allergist.
The increase in winds associated with climate change could be distributing pollen farther, potentially exposing people to new varieties of it, said Dr. Mary Johnson, a research scientist at Harvard.
Research has also shown that hormones, including estrogen, progesterone and testosterone, can affect how allergic diseases develop.
Boys often have food allergies or eczema as babies and seasonal allergies or asthma in childhood but then have those conditions disappear when they hit puberty, Dr. Kachru said. But symptoms can return when they reach their 30s and 40s.
For some women, major hormonal shifts, including those that happen during puberty, pregnancy and menopause and while on birth control, can affect the onset and severity of allergy symptoms, Dr. Kachru said.
How do I manage the symptoms?
The first step is to reduce exposure. Keep your windows shut to prevent pollen from blowing into your home.
