Allercy and Asthma Health
The Official Publication of AAN - MA

Test Your Indoor Allergen Knowledge


by Walton B. Wilson, MHS, RRT

Overall, Americans spend approximately 60% of their time inside their homes, and a significant amount of their remaining time is spent indoors at work or school. Most people think of outdoor allergens, such as pollen, when they think of asthma triggers, but because of the time spent indoors, it is important to recognize the common indoor allergens that can cause problems as well.

The following questions will test your indoor allergen knowledge about three of the most common triggers.

1. You wake up each morning with a runny nose, itchy eyes, chest tightness, and wheezing. What is the most likely indoor allergen that is causing your symptoms?

The answer is dust mites! Actually, it is not the dust mites, rather it is their waste products. Dust mites are common in pillows, bedding, cloth furniture, carpet, and even stuffed animals. They feed on human skin cells that are shed throughout the home. Dust mites love warm and humid climates.

There are several specialty products available for dust mite prevention; however, simple cleaning techniques are just as effective. Bedding should be washed in hot water (130 °F) once a week. Pillows and stuffed animals that cannot be washed can be placed in a sealable bag and put in the freezer for 24 hours, which will kill the dust mites.
2. You keep your home warm and rarely use central heat or air conditioning. You notice that several areas of your home have mildew. Every time you attempt to clean your home, symptoms of an asthma attack begin to develop. What is the most likely indoor allergen that is causing your symptoms?

The answer is molds! Molds are generally not an issue until they are disturbed by home cleaning, maintenance, and/or renovations. All of these tasks cause the molds to become airborne, which makes them easy to inhale. Molds are extremely irritating to a person’s airway, especially if he or she has asthma and is sensitive to them.

Molds grow best in damp areas, such as under sinks, in bathrooms, and in carpets that have been or are wet. Bleach-based cleaners for surfaces are effective on most hard surfaces (of course, be careful to avoid the irritating fumes of the cleaner). Vacuum cleaners with high efficiency particulate air (HEPA) filters and damp cloths/mops should be used to prevent the molds from becoming airborne. A HEPA mask may be helpful in reducing inhalation of molds when sweeping or performing demolition.

3. You are the proud owner of a dog. He primarily remains outside during the day, but he is allowed indoors in the evening. Each evening your asthma symptoms recur. What is the most likely indoor allergen that is causing your symptoms?

The answer is pet dander! Most people think they are allergic to the animal’s fur itself, but in reality, it is the proteins in saliva, skin, and urine that are in the fur that cause the allergy. When pets scratch or shake, they cause these flaky allergens to become airborne and be inhaled.

Of course, the easy remedy for these allergens is not owning pets. If you are a pet lover who is allergic to pet dander and are intent on having a pet (especially indoors), your asthma risks are increased significantly. Bathing pets frequently, preventing them from lying on furniture and bedding, and using a HEPA filtration system may all reduce the amount of dander, but you must realize these measures will not be 100% preventative. Be ready for allergy shots!

Walton Wilson is a member of the American Association for Respiratory Care from Natchez, MS, where he currently serves as program director of the respiratory care technology program at Copiah-Lincoln Community College.


  • Leitch M. Try This Allergy Test: Three Little-Known Facts About Indoor Allergens. Newswise.
  • Perretta JS. Neonatal and Pediatric Respiratory Care. Philadelphia: F.A. Davis Company 2012.
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