Itchy eyes, a congested nose, sneezing, wheezing and hives: these are symptoms of an allergic reaction to the environment caused when plants release pollen into the air, usually in the spring or fall. Many people use hay fever as a colloquial term for these seasonal allergies and the inflammation of the nose and airways.
But hay fever is a misnomer, said Dr. Jordan Josephson, an ear, nose and throat doctor and sinus specialist at Lenox Hill Hospital in New York City.
"It is not an allergy to hay," Josephson, author of the book "Sinus Relief Now" (Perigee Trade, 2006), told Live Science. "Rather, it is an allergy to weeds that pollinate."
Doctors and researchers prefer the term "allergic rhinitis." About 8 percent of adults in the United States have allergic rhinitis, Josephson said. Among children in the United States, 9 percent reported having allergic rhinitis symptoms during the past 12 months, according to a 2012 study, he added. [Check out our 2017 guide for coping with allergies and asthma.]
Worldwide, between 10 and 30 percent of people are affected by allergic rhinitis, he said.
The symptoms of allergic rhinitis may at first feel like those of a cold. But in the case of hay fever, symptoms usually appear when a person encounters an allergen, such as pollen or mold.
Symptoms include itchy eyes, itchy nose, itchy throat, itchy ears, sneezing, irritability, nasal congestion and hoarseness. People may also experience cough, postnasal drip, sinus pressure or headaches, decreased sense of smell, snoring, sleep apnea, fatigue and asthma, Josephson said.
Many of these symptoms are an immune overreaction by the body attempting to protect the vital and sensitive respiratory system from outside invaders. The antibodies produced by the body succeed in keeping the foreign invaders out, but also cause the symptoms characteristic of allergic responses.
People can develop hay fever at any age, but most people are diagnosed with the disorder in childhood or early adulthood, according to the Mayo Clinic. Symptoms typically become less severe as people age.
Often, children may first experience food allergies and eczema before developing hay fever, Josephson said. "This then worsens over the years, and patients then develop allergies to indoor allergens like dust and animals, or seasonal rhinitis, like ragweed (hay fever), grass pollen, molds and tree pollen."
Hay fever can also lead to other medical conditions. People who are allergic to weeds are more likely to get other allergies and develop asthma as they age, Josephson said. But those who receive immunotherapy, such as allergy shots that help people's bodies get used to allergens, are less likely to develop asthma, he said.
The most common allergen is pollen, a powder released by trees, grasses and weeds that fertilize the seeds of neighboring plants. As plants rely on the wind to do the work for them, the pollination season sees billions of microscopic particles fill the air, and some of them end up in people's noses and mouths.
Spring bloomers include ash, birch, cedar, elm and maple trees, plus many species of grass. Weeds pollinate in the late summer and fall, with ragweed being the most volatile. The pollen that sits on brightly colored flowers, it is interesting to note, is rarely responsible for hay fever, because it is heavier and falls to the ground rather than being borne in the air. Also, bees and other insects carry that pollen directly from one flower to the next without ever bothering human noses.
Mold allergies are different. Mold is a spore that grows on rotting logs, dead leaves and grasses. While dry-weather mold species exist, many types of mold thrive in moist, rainy conditions, releasing their "seeds" overnight. Both in the spring or fall allergy seasons, pollen is released mainly in the morning hours and travels best on dry, warm and breezy days.
In 2017, spring arrived unusually early, according to a study led by the U.S. Geological Survey (USGS). Spring means blooming flowers and, for some, lots of sneezing, itchy, watery eyes and runny noses. By looking at various spring indices, including the blooming of known temperature-sensitive flowering plants, the researchers created maps showing when spring had sprung this year. For instance, the maps showed that spring reared its head at the end of February in coastal California, southern Nevada, southeastern Colorado, central Kansas, Missouri, southern Illinois, Indiana and Ohio. Spring arrived 22 days early in Washington, D.C., those maps showed.
How do scientists know how much pollen is in the air? It’s more than just a guess. Specialists charged with counting pollen set a trap where ambient air flows freely. The trap — usually a glass plate or rod coated with adhesive — is analyzed every few hours, and the number of particles collected is then averaged to reflect the particles that would pass through the area in any 24-hour period. That measurement is converted to pollen per cubic meter. Mold counts work much the same way.
A pollen count is an imprecise measurement, scientists admit, and an arduous one — at the analysis stage, pollen grains are literally counted one by one under a microscope. It is also highly time-consuming to discern between types of pollen, so they are usually bundled into one variable. Given the imprecise nature of the measurement, total daily pollen counts are often listed simply as low, moderate or high.
The American Academy of Allergy, Asthma & Immunology provides up-to-date pollen counts for U.S. states.
People who have access to pollen counts may decide to stay indoors if a pollen count is high, or simply may take medication to help control their symptoms.
Tests & diagnosis
A physician will take patient history and do a thorough physical examination if a person reports having hay fever-like symptoms. If necessary, the physician will do an allergy test. According to the Mayo Clinic, people can get a skin prick test, in which doctors prick the skin on a person's arm or upper back with different substances to see if any cause an allergic reaction, such as a raised bump called a hive.
A person can also do an allergy blood test. This test rates the immune system's response to a particular allergen by measuring the amount of allergy-causing antibodies in the bloodstream, according to the Mayo Clinic.
Hay fever treatments
Dr. Sarita Patil, an allergist with Massachusetts General Hospital's Allergy Associates in Boston, talked to Live Science about strategies for outdoor lovers with seasonal allergies. Patil suggested seven tips. For instance, Patil suggested figuring out exactly what type of pollen you're allergic to, and then avoiding the months when those plants are in bloom. Her other strategies: Be able to identify the pollen perpetrator by sight; monitor pollen counts before scheduling outdoor time; go outside at a time of day when the plants that make you go achoo are not pollinating (grasses, for instance, have a peak pollination time of afternoon to early evening); wear protective gear like sunglasses, among other tips.
Allergy sufferers may also choose to combat symptoms with medication designed to shut down or trick the immune sensitivity in the body. Whether over-the-counter or prescription, most allergy pills work by sending chemicals that bind naturally to histamine — the protein that reacts to the allergen and causes an immune response — coursing through the body, negating the protein’s effect.
Other allergy remedies attack the symptoms at the source. Nasal sprays contain active ingredients that decongest by soothing irritated blood vessels in the nose, while eye drops both moisturize and reduce inflammation. Doctors may also prescribe allergy shots for those particularly afflicted, Josephson said.
For kids, allergy medications are tricky, according to a nationally representative poll of parents with kids between the ages of 6 and 12. That study, carried out in January 2017 by the University of Michigan's C.S. Mott Children's Hospital, found that 21 percent of parents said they had trouble figuring out the correct dose of allergy meds for their child; 15 percent of parents gave a child and adult form of the allergy medicine, with one-third of these parents giving their child the adult dose of that medicine.
Doctors may also recommend allergy shots, a neti pot that can rinse the sinuses, or a Grossan Hydropulse, an irrigating system that cleans the nose of pollens, infection and environmental irritants, Josephson said.
Alternative and holistic options, along with acupuncture, may also help people with hay fever, Josephson said. People can also avoid pollen by keeping their windows closed in the spring, and by using air purifiers and air conditioners at home.
Probiotics may also be helpful in stopping those itchy eyes and runny noses: After analyzing more than 20 previous, and relevant, studies, researchers found that those who suffer from hay fever may benefit from using probiotics, or "good bacteria" thought to promote a healthy gut. Though the jury is still out on whether probiotics are an effective treatment for seasonal allergies, the researchers noted these gut bacteria could keep the body's immune system from flaring up in response to allergens, something that could reduce allergy symptoms. The study was reported in 2015 in the journal International Forum of Allergy & Rhinology. Probiotics can be found in certain foods such as yogurt as well as in supplements. [5 Myths About Probiotics]