science of us

Everything You Need to Know About Seasonal Allergies

Photo: George Marks/Getty Images

It hardly seems fair. Just as the days start getting longer and warmer, and people have finally stopped spreading their flus and colds around the office, the misery begins all over again. Welcome to allergy season.

According to the Centers for Disease Control and Prevention, seasonal allergies are a leading cause of chronic illness in the U.S., with a reported 50 million Americans suffering every year. In the last 12 months alone, more than 8 percent of the U.S. population were with diagnosed with hay fever.

And yet it seems like every year, we ask ourselves the same questions: How can you tell the difference between allergies and a cold? How long does allergy season last? Why do we get allergies in the first place? We spoke with Ronald Saff, M.D., Fellow of the American Academy of Allergy Asthma and Immunology at the Allergy and Asthma Diagnostic Treatment Center, to find out.

What exactly are we allergic to?
Different people have different allergens, but the most common outdoor, seasonal allergies are tree, grass, and weed pollen, as well as ragweed, a plant that grows wild almost everywhere across the US.

But the only way to know exactly what you’re allergic to is to have a skin test, Saff said. “Some patients come to my practice saying they’re allergic to pets. We do a skin test and it turns out their cat is going outdoors and bringing pollen inside, and the patient is actually reacting to that,” Saff says.

What are the symptoms of seasonal allergies?
Classic symptoms are sneezing, itching, watery eyes, runny nose, and nasal congestion. Some people with allergies also have underlying asthma, which can cause them to also experience coughing, wheezing and chest tightness.

How can I tell the difference between seasonal allergies and a cold?
Allergies usually cause sneezing, itchy, watery eyes, and a runny nose, but you’ll probably feel well enough to go to work, for example. A cold might come with muscle aches and pains and nausea, and just a general feeling of being unwell.

When does allergy season start in 2018? And when will it end?
The timing and severity of an allergy season varies across the country. Pollen season starts in spring and lasts through the summer, starting to taper around May. Right now, we’re in the middle of tree-pollen season, when most allergists are at their busiest, so people feeling allergy symptoms may be allergic to oak, hickory, pecan, and elm trees.

Why do we get allergies?
There isn’t one straightforward answer to this, but experts believe several things can cause allergies.

First, genetics. “There’s a strong suspicion that there’s a genetic component,” Saff says. If one biological parent has allergies there’s a bigger chance the child will have allergies, too, and this chance increases if both parents have allergies. But it’s also possible for someone to develop allergies when neither of their parents have them.

It can also depend on our childhood, according to Saff. “It’s thought that early exposure to allergens, such as dust mites or pets, in early childhood, coupled with a viral infection in proper settings, can lead one to developed allergies over time.”

But it’s not just our genetics and upbringing — there could be something much bigger behind your sneezing fits. “I’m certainly seeing more patients in my practice, and one of the drivers is global warming. We know that the elevated levels of CO2 in the atmosphere cause ragweed plants to release more ragweed pollen,” Saff says.

Warmer weather also tricks trees into thinking spring has come earlier. “They’re pollinating early every year, and for longer through the spring,” says Saff, meaning trees are releasing more pollen over longer periods of time.

How can we avoid allergic reactions?
For grass or tree allergens, Saff advises keeping the windows closed in your house and car to prevent pollen from blowing in, and wearing sunglasses and a hat when you’re outside, so pollen doesn’t flow into your eyes and face. If you’ve been outside for a long time, it’s not a bad idea to shower as soon as you’re back indoors, so you can wash pollen grains off your skin and hair.

Can we prevent allergies from happening in the first place?Possibly. There’s a lot of research around this, and there’s a concept called the “hygiene hypothesis,” which argues children should be brought up around some degree of dirt and germs. It’s thought that being exposed to a lot of other children, as well as farm animals, and not washing too often, can strengthen a child’s immune system because it works outward, fighting off viruses and getting a “healthy workout,” as Saff puts it.

If, on the other hand, you lived in environment that could be considered too clean, or perhaps you were an only child and didn’t go to day-care, your immune system might not have got that workout. “It doesn’t have viruses to fight off, or dirt and pathogens, so the immune system turns inward, and it’s thought this can cause a host of other auto-immune diseases that develop,” Saff says.

How can we treat allergies?
Aside from minimizing your exposure to allergens, there is medication available to help with symptoms. The most effective medications are nasal sprays, Saff says. “They spray right into the nose and sinuses, which is the area allergies take place, so they’re very targeted,” he said. He recommends nasal steroids over the counter, coupled with prescription anti-histamine. But you can also get allergy shots in your arms over a period of around four years, which Saff recommends as a long-term solution.

Everything You Need to Know About Seasonal Allergies