Your 365-Day Guide to Allergies and Asthma: 13 Seasonal Allergies and Symptoms

April showers bring May flowers, but they also bring out boxes of tissues. It's hay-fever season, and sneezing and itchy eyes can make kids miserable. Spring is also tough for the 5 million children in the U.S. who have asthma, because about half of their bouts of breathing problems are triggered by pollen and other airborne allergens. Your child's wheezing or sneezing may ease up once this peak allergy season has passed, but kids can be bothered by asthma and allergies all year long. "Every season brings a different set of irritants and allergens," says Stanley Fineman, M.D., a pediatric allergist in Atlanta. The right medications will provide relief, but there's a tremendous amount you can do to prevent symptoms before they start.

Season: Spring

Tame it: Try to keep your allergic kids inside on windy days, when pollen is blowing around, and before 10 a.m., when pollen counts are highest. Keep windows closed and air-conditioning on in both your home and car. Because pollen sticks to skin, hair, and clothes, kids with allergies or allergy-induced asthma should wash their hands and face and if possible change into clean clothes when they come indoors, says Michael Zacharisen, M.D., an allergist at Children's Hospital of Wisconsin, in Milwaukee. Leave a basket by the door for shoes, so no one will track pollen through the house. And don't line-dry clothes, towels, or linens outside where they'll attract pollen and mold.

Season: Spring

Tame it: Your annual big cleanup is a great way to get rid of dust and mold, if you do it properly. Use a damp cloth to trap allergens, and use a vacuum with a high-efficiency particulate air (HEPA) filter. If possible, do your cleaning when your child can be out of the house for several hours, especially if you're going to be stirring up large amounts of dust by taking down draperies or cleaning light fixtures.

Season: Summer

Tame it: Children breathe more rapidly and inhale more air pollutants than adults do. Kids with asthma are particularly sensitive to the ozone in urban smog, which limits their ability to take deep breaths. Air pollution is at its worst on hot, humid days. Check your city's air-quality index by visiting airnow.gov. On high smog days (some areas call these "Ozone Action Days"), your asthmatic child should limit vigorous exercise as well as time spent outdoors, especially from 11 a.m. to 8 p.m., when smog is most intense.

Season: Summer

Tame it: Central A.C. is the best way to filter outside allergens and reduce humidity (which promotes the growth of dust mites and mold), but your unit needs to be properly maintained. "The fiberglass filters used in most home-cooling units do little to remove contaminants from the air," says Jeffrey C. May, a certified indoor-air specialist and author of My House Is Killing Me! The Home Guide for Families With Allergies and Asthma. Choose air filters with a minimum efficiency reporting value (MERV) of 10 or higher, meaning they trap tiny particles like dust, pollen, and mold, and replace them every three months or when the seasons change. If you're using window units, clean them thoroughly once a year, don't leave them in the window year-round, and upgrade the filter to one with a high MERV rating. If you don't have air-conditioning, window filters like Safeguard and MicroAirScreen limit the amount of pollen that comes inside. Oscillating fans can contribute to poor air quality by circulating allergens, but ceiling fans equipped with air-purification systems like Purifan (not paste-on filters for fan blades) clean the air while cooling.

Season: Fall

Tame it: Back-to-school season is often back-to-sneezing season because ragweed, the number-one cause of fall allergies, is such a hardy and prolific plant. This flowering weed pollinates from mid-August to October and is most common in the Northeast, South, and Midwest. Unfortunately, it's hard to avoid being exposed: A single ragweed plant produces about a billion pollen grains that can travel as far as 400 miles. However, these pollen levels tend to be at their highest at midday, so plan your child's outdoor activities before 10 a.m. or after 4 p.m.

Season: Fall

Tame it: A trip to the pumpkin patch or apple orchard can cause trouble for children with allergies and asthma. "Mold spores thrive in these damp, earthy places," Dr. Zacharisen says. You should also limit your child's exposure to straw, hay bales, cornhusks, and piles of leaves, which harbor mold. Make sure your child washes up and changes clothes after a fall outing.

Season: Fall

Tame it: Chlorine-saturated pools often trigger asthma symptoms. However, swimming is a great activity for kids with asthma because the warm, moist air soothes their airways. Outdoor pools are the safest because the irritating chlorine gas doesn't accumulate, but if your child does swim indoors, choose a pool that is well ventilated.

Season: Winter

Tame it: Kids with asthma are particularly sensitive to frosty air, which can constrict their airways. Make sure your child wears a scarf or a neck gator over his nose and mouth to warm the air he breathes.

Season: Winter

Tame it: They're not allergens per se, but fragrances in candles, potpourri, incense, and air fresheners can inflame an asthmatic child's airways or bring on an allergic sneezing fit. Avoid these products and ask family and friends to do the same when you visit.

Season: Winter

Tame it: Mold spores, found on the tree and in the water it sits in, can trigger both allergies and asthma. If you must have a live tree, buy from a retailer who uses a machine to shake off loose needles, and kill mold by wiping the trunk thoroughly with a bleach solution (mix one part bleach to 20 parts warm water). Artificial trees are a safer alternative if you store them correctly. "Keep the tree in a sealed plastic bag in a dry, clean area, not on the basement floor where it'll collect dust and mold," Dr. Fineman says. Evergreen wreaths and other live greenery also carry mold spores, so use them sparingly.

Season: Winter

Tame it: Talk to your child's doctor before using a humidifier because excess humidity promotes mold growth and dust mites. "Increased humidity normally alleviates cold symptoms, but an asthmatic or allergic child's condition can actually get worse from exposure to mold and dust mites," Dr. Zacharisen says. If your doctor gives the okay, look for a unit equipped with a humidistat that shuts off the device when the humidity in the room reaches a set level, or buy an inexpensive humidity gauge at the hardware store called a hygrometer. It's also crucial to clean a humidifier frequently.

Season: Winter

Tame it: Forced-air furnaces circulate airborne dust, animal dander, and other allergens. "Have your ducts cleaned professionally with brushes and vacuums that have HEPA filters," says May. You should also vacuum vents regularly using your HEPA vacuum's attachments.

Season: Winter

Tame it: Fireplaces make our homes feel warm and cozy when it's cold out, but they're a major problem for kids with asthma. "Wood smoke contains most of the same toxins, except for nicotine, as tobacco does, and they can get deep into a child's lungs," says pediatric pulmonologist Harold J. Farber, M.D., author of Control Your Child's Asthma. "If you must have a fireplace, get a gas fireplace, which produces much less pollution than a wood-burning one."

Trigger: Wood playground mulch; indoor plants; sandboxesCulprit: Mold

Trigger: Down-filled coatsCulprit: Dust mites

Trigger: Stuffed animalsCulprit: Dust mites and dander

Trigger: Fish tanks; Covers for pools and hot tubsCulprit: Mold and dust mites

Trigger: Melons and bananasCulprit: Ragweed allergy