Seasonal allergies in kids are common throughout the spring, summer, and fall. Learn about the signs of hay fever and tips for combatting it. 
kids blowing dandelions in field
Credit: Getty Images

Every year, about 6.1 million American kids suffer from hay fever, also called allergic rhinitis, according to the Asthma and Allergy Foundation of America. These seasonal allergies are caused by an overreaction of the immune system to certain things outdoors, like molds and pollens from grasses, trees, and other plants such as ragweed.

The percentage of kids with hay fever has actually doubled over the past two decades, says Parents advisor William E. Berger, M.D., an allergist in Mission Viejo, California. No one knows exactly what's behind the trend, but many scientists say that our increasingly sanitized environment is diminishing kids' exposure to everyday microbes that bolster their immune system. Others believe that global warming is leading to consistently higher pollen counts. 

Thankfully, as allergy rates grow, so has awareness, and doctors are getting better at diagnosing kids. Here's what parents need to know about recognizing the signs of hay fever and stopping them from progressing.

What is Hay Fever?

The term "hay fever" is actually a misnomer, because hay doesn't actually cause the symptoms. Instead, the culprits are pollens from plants, trees, and grasses—as well as molds that thrive in warm, moist, and shady environments.  "Reactions to ragweed in the fall receive a lot of attention, but trees and grass in the spring can trigger ferocious allergies," says Laurie Smith, M.D., who chairs the section on allergy and immunology at the American Academy of Pediatrics. 

When pollen grains or mold spores enter nasal passages, the immune system may perceive these harmless things as a threat. In defense, cells release chemicals such as histamine—which causes sniffling, sneezing, itching, and other common symptoms of hay fever.

Seasonal hay fever usually develops after a few years of exposure to an outdoor allergen, so it's uncommon in children younger than 2. The typical age for diagnosis is around 4 to 6 years old. Symptoms generally peak in late childhood and adolescence, and then improve during adulthood.

Hay Fever Symptoms

Making the distinction between colds and hay fever can be difficult; a clue is often the duration of symptoms. According to Fuad Baroody, M.D., director of pediatric otolaryngology at the University of Chicago Medical Center, allergies generally last longer than two weeks, while colds only last a handful of days. 

Also, allergic kids often just look different from sick kids, says Dr. Berger. Many have "allergic shiners," dark circles that form under the eyes due to chronic congestion, or rub their drippy noses upward in what docs call an "allergic salute." Other symptoms of hay fever include sneezing; stuffy or runny nose; cough and scratchy throat due to postnasal drip; puffy, watery, itchy eyes, mouth, or skin. 

When to Expect Seasonal Allergies in Kids

Allergy season differs depending on the specific trigger. As a general rule, trees pollinate in the spring, grasses bloom in mid- to late spring or early summer, and weeds in the late summer or early fall. Mold spores tend to be a summer to early-fall phenomenon—although they're present year-round in certain climates. 

Cold winter weather is a blessing for many kids with seasonal allergies, who can count on a break until at least February. A warmer winter can cause plants to pollinate early, meaning sufferers' symptoms start up sooner than usual. A rainy spring can also promote rapid plant growth and lead to an increase in mold, with effects that last well into the fall. Rain can wash away pollen, but the relief is only temporary since pollen counts can rise rapidly following wet weather.

Other weather clues that may help you to head off your child's worst symptoms: Warm, windy days generally lead to a high pollen count, whereas calm days can leave all that pollen on the ground rather than flying into your child's nose.

Allergy Testing for Hay Fever

If your child has had allergy testing, the results will be much more useful than relying on monitoring the overall pollen count. If she's not allergic to ragweed, for example, then a high ragweed count shouldn't keep her off the playground.

Children who only have allergies in certain seasons are likely allergic to pollens or mold spores that appear at specific times of year. Doctors can perform skin prick tests and/or blood tests to help you learn which types of pollen cause your child's flare-ups, and you can monitor pollen counts to know when to start medicines and, on the worst days, when to limit your child's time outdoors. 

Many weather services report overall pollen levels or levels of specific allergens such as ragweed, the most common cause of hay fever. The National Allergy Bureau, a service of the American Academy of Allergy, Asthma, & Immunology, provides reports on pollen from specific species of trees, weeds, and grasses around the country—as well as mold-spore counts—at

Hay Fever Prevention and Treatment

If your child has seasonal allergies, he should ideally start taking medication at least two to three weeks before the beginning of the season (which depends on his specific allergy) and continue them through the end.

Most allergy medicines are far more effective at preventing symptoms than treating them. That's because the runny nose, stuffiness, itching, sneezing, and watery eyes result from a whole cascade of events in the immune system, and once it gets going, it's hard to stop. Corticosteroid nose sprays (available over-the-counter) are the most effective type of hay fever medicine, and they're safe for children 2 and older. They prevent the cascade by decreasing the immune system's response to antigens like dust mites and pollen.

Antihistamines can help relieve symptoms during an attack, but they are even more effective if they're in the bloodstream before the attack starts. Allergy medicines, which may either be prescribed or bought over-the-counter, are often given once a day—which means they need about five days to reach their full strength and another five to wear off completely. Oral antihistamines relieve many allergy symptoms (including sneezing and itchy eyes) by blocking histamine, the chemical "culprit" in the body, but they don't relieve nasal congestion.

If your child has severe hay fever, your pediatrician or allergist may decide on allergy shots, or immunotherapy. Doctors will inject a small amount of the allergen that affects your child, and the amount is increased over time until eventually the patient is on a maintenance dose. This is not a quick fix—kids who take allergy shots can do it for months or years to achieve benefits. Most people start seeing benefits within about 12 months, and keep up the shots for 4 or 5 years.