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This information was reviewed and approved by Ronina A. Covar, MD (6/1/2017).

Allergies can make asthma worse, although not all children with asthma have allergies, and not all children with allergies have asthma. In children with allergies, the immune system becomes sensitive to normally harmless substances known as allergens.

Common allergens include pollens, mold spores, animal dander from feathered or furry animals, dust mites (a major component of house dust in humid climates) and cockroaches. On contact with the allergen, the allergic person’s body produces chemicals that irritate the inflamed airways and lead to symptoms. Allergy symptoms may include itchy eyes, runny nose, asthma symptoms, skin problems (eczema) and/or a rash.

Depending upon your child’s medical and family history, age and environment, allergy testing may be necessary. We recommend that testing be done under the supervision of a board-certified allergist. In most cases, skin testing for allergens is preferable to blood tests. Knowing if your child is allergic, and to what, can help you take appropriate measures in your home to decrease exposure to these allergens.

Although many of the measures are for the entire home, the bedroom is the most important, because the bedroom is where children usually spend one-third to one-half of their time.



Pollens from trees, shrubs, grasses and weeds can cause allergy symptoms. Pollen may travel many miles. Therefore trees, grasses and weeds in your general area can cause allergy symptoms.

Actions You Can Take

  • If possible, keep windows and outside doors shut during pollen season, especially during the daytime.

  • Pollen count is highest during the midday and afternoon. Consider this when planning outdoor activities.


Mold Spores

Mold can grow in damp areas of your home, such as the kitchen and bathroom. If your child is allergic to mold, take measures to decrease mold growth.

Actions You Can Take

  • In the bathroom, use an exhaust fan or open a window to remove moisture after showering. Wipe down surfaces after showering. Wash bathrooms with a mold-preventing or mold-killing solution.

  • In the kitchen, use an exhaust fan to remove water vapor when cooking. Discard spoiled foods immediately.

  • Empty the garbage daily.

  • Keep indoor moisture low. The ideal humidity is 30 – 40 percent.

  • Use a dehumidifier in the basement if the humidity is high.

  • Air conditioning can help decrease the humidity.


Animal Dander

Animal dander (dead skin that is continually shed), urine, feces and saliva from feathered or furry animals can cause allergy symptoms. Cats, dogs, birds, rodents (hamsters, gerbils) and horses are common examples of feathered or furry animals.

If you do not own a feathered or furry pet, do not get one, because your child can develop allergies with repeated exposure.

Actions You Can Take

  • Remove the animal from your home.

  • If you must have a pet, keep it out of the allergic person’s bedroom at all times. Keep your child’s bedroom door closed, and put a filter over air vents in the bedroom.

  • Keep the pet away from upholstered furniture and carpet as much as possible.

  • Avoid visits to friends and relatives with pets when possible.

  • Ask your doctor about using an inhaled medication before you visit a home with a pet.

  • Choose a pet without fur or feathers. Snakes and fish can be good pets. 


House Dust Mites

Dust mites are insects, not visible with the naked eye, that live in bedding, carpets, stuffed furniture, old clothing and stuffed toys. They feed on human dander. Dust mites are common in humid climates.

Actions You Can Take

  • Enclose the mattress and box springs in a zippered dust-proof encasing. Dust-proof encasings have a layer of material that keeps the dust mites inside the encasing.

  • Wash all bedding in hot (130° F) water weekly.

  • Put the pillows in zippered dust proof encasings and/or wash the pillows weekly with the bedding.

  • Do not use a humidifier or evaporative (swamp) cooler.

  • Keep the indoor humidity below 50 percent.

  • Keep stuffed toys out of the bedroom, or wash them weekly in hot water.


Pests: Cockroaches and Rodents

Cockroach and rodent (mouse, rat) allergies are common in inner cities and humid areas.

Actions You Can Take

  • Keep food out of the bedroom.

  • Keep food and garbage in closed containers.

  • Discard spoiled foods immediately. Empty the garbage daily.

  • Use poison baits, boric acid or traps to control cockroaches. Keep these out of children’s reach.

If chemical sprays are used, the home should be well ventilated, and the child with asthma should stay away from home until the smell dissipates.


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