If you’ve been sneezing, coughing, congested, or have had a runny nose or itchy eyes in the past few weeks, chances are it’s not a cold or COVID. It’s more likely you are among the 82 million Americans living with seasonal allergies.

According to the National Center for Health Statistics and the Asthma and Allergy Foundation of America, 25.2% of adults 18 and older, and 20.6% of children, have seasonal allergies. And year-round allergies are becoming ever more common.

“When we are talking about people having allergies, what we are saying is that their body has developed an immune response to something in their environment,” explains Dr. Manav Segal, a board-certified allergist and immunologist, and owner of Chestnut Hill Allergy and Asthma Associates in Wyndmoor. “It is increasingly the case that [patients] are allergic to more than one thing.”

Indoor allergens include irritants like dust mites and cat or dog dander. Outdoors, the reaction may be caused by grass, tree or ragweed pollen.

“Many of our patients have many things they are allergic to,” Segal says. “Once tree pollen season is over [in spring], they are also allergic to grass pollen. So their symptoms roll right into summer. Fifty percent of people with environmental allergies are specifically allergic to ragweed also.”

Ragweed season begins in August and usually peaks sometime in mid-September. But it takes the first frost to pull the plug on ragweed and other pollen. And the first frost is coming later each year because of climate change.

A warmer planet is a significant reason why year-round allergies are becoming more common. In the past few decades, pollen counts have risen steadily. With warmer temperatures comes a longer growing season and, again, a later first frost.

“Heat results in accelerated plant growth,” Segal says. “Increased humidity and moisture are also going to promote plant growth, and high carbon dioxide levels promote plant growth. And that includes ragweed and trees that pollinate in the spring.”

A study published in February 2021 issue of the peer-reviewed Proceedings of the National Academy of Sciences of the United States of America (PNAS), reported that, “Long-term increases in pollen season length and annual pollen integrals indicate that exposure times to allergenic pollen as well as amount of pollen have increased significantly for North America in recent decades.”

It further found “a substantial intensification of pollen seasons in North America over the 1990–2018 period.”

“Pollen counts, year over year and certainly decade over decade, are much higher than they have been in the past,” Segal says. “And they are predicted to rise.”

And because pollen is invisible, light weight, and is carried by the wind, there is no escaping it. Ragweed, specifically, can be carried hundreds of miles, Segal says. So, if you think the city’s asphalt and concrete offers sanctuary, you’re wrong. In fact, the city may actually exacerbate allergy symptoms.

“There is some literature that suggests that within the downtown areas of cities, we have our own micro climate that is hotter than the suburbs,” he says. “We have, in some instances, higher pollen counts with things like ragweed in the city than we might have in the suburbs and even rural areas.”

Allergies are becoming more common. But how they affect people can vary greatly. For some, allergies are a nuisance usually relieved by any one of several over-the-counter antihistamines, nasal sprays and eye allergy medications. But for other people, allergies can develop into a serious medical condition.

“For our patients who have those more severe allergy symptoms, I would estimate that about 75% of them also have asthma or have developed asthma,” Dr. Segal says. “What I mean is that their environmental allergies are not just affecting their eyes or nasal passages. They are also affecting their lungs. They are developing coughing, wheezing and shortness of breath.”

Patients exhibiting serious symptoms should talk to their primary care physician. If they have frequent sinus infections, it may be time to see an allergist.

“If they are ending up on antibiotics one, two or three times a year, that would be a reason to talk to an allergist about what can be done to reduce how frequently they are getting sick,” he says.

Having symptoms when you have environmental allergies is one thing. But to test negative and still have symptoms? It happens quite frequently now, Segal says, especially when pollen counts are particularly high.

“Pollen is an irritant and an inflammatory,” he says. “If it is blowing right into your eyes, it is going to make anyone’s eyes irritate, itch and burn. If it is blowing into your nasal passages, it is going to make anyone’s nose irritated and make them sneeze, or have their nose run, or be congested.”

As if respiratory allergy symptoms aren’t bad enough, Segal says patients are also reporting itchy mouths after eating fruits and vegetables. Turns out that fruits and vegetables like melons, peaches, plum, pears, cherries, apples, zucchinis and cucumbers contain proteins that are cross reactive with certain pollen.

“Similar proteins found in ragweed pollen are also found in those fresh fruits and vegetables,” he says. “We call that, with both ragweed and birch pollen, oral allergy syndrome, or another name could be fruit pollen syndrome.”

Patients who want a more enduring solution to their allergy symptoms can undergo allergen immunotherapy, which involves a series of desensitizing shots.

“You will feel better within six to eight months and you will stay better with monthly injections,” Segal says. “People who complete at least three years of allergy shots won’t need the shots anymore. It leads to long-term change in their immune system.”