Outdoor and Indoor Allergens
An allergen is something in your environment that can cause sneezing, itchy red eyes, and nasal congestion. If you have asthma, allergies can also cause coughing and wheezing. Common allergens include pollens, molds, dust mites and furred animal dander.
Seasonal allergens in Wisconsin
- Tree pollen occurs mid-March to late-May.
- Grass pollen occurs from the end of May to 1st part of July.
- Ragweed pollen occurs at the start of August or lasts until first frost (peak time is when school begins).
- Alternaria (mold) peaks in early July through October and may be present until snow cover.
- Outdoor pollens are carried by wind. Some pollen can travel hundreds of miles by wind. As a result, it is not helpful to remove or change the plants or trees in your yard.
Indoor year round allergens
- Dust mites live in hot, humid places. They are often found in bedding, upholstery, and carpet. Dust mites feed on dead skin cells shed by the human body. People are allergic to the dust mite droppings as well as the mites themselves. (Ask for HFFY #6180 for details on how to control dust mites in your home.)
- Pets: Cats and dogs have allergens in their dander (dead skin flakes) and saliva. Hamsters, mice, rabbits, guinea pigs have allergens in their urine. Even farm animals such as horses and cattle can cause allergy symptoms. Removing pets from the home is the best option. It helps to keep pets away from living areas and out of the bedroom by keeping the doors closed. Washing the hands and face after being around pets may also be helpful.
- Cockroaches are important allergens. They live in hot, humid areas and need food and water to survive. Keeping the home dry and clean helps to keep cockroaches out of the home.
Common Molds: Molds can be found both indoors and outdoors. Molds thrive in moist areas.
- Aspergillus can be found in soil. It grows on damp hay, grain, sausage, and fruit
- Alternaria grows outdoors on plants and plant matter on and in the ground.
- Cladosporium can be found in plants, wood products, and leather goods.
- Penicillium can be found in soil though it easily grows on fruits, breads, and cheeses. It should not be confused with penicillin, the antibiotic.
The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Any duplication or distribution of the information contained herein is strictly prohibited.
Last Updated: 08/24/2009
Copyright © 08/24/2009 University of Wisconsin Hospitals and Clinics Authority. All rights reserved. Produced by the Department of Nursing. UWH #6358
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