Background Having any kind of Allergy can be bothersome, but molds are especially so as they can grow invisibly anywhere in the house where it is cool and damp. Molds represent a group of airborne allergens, many of which are present year-round in the home or other indoor environments. Seasonally, mold spores may "bloom" following rainy or humid periods, resulting in increased concentrations in the air. Mold is most common indoors in damp locations such as swamp coolers, basements, bathrooms, or washrooms. Fabrics, rugs, stuffed animals, books, or wallpaper can harbor mold spores if they are frequently in contact with water or kept in a damp place. Outdoors, mold lives in the soil, on compost, and on damp vegetation.
Incidence and Prevalence It has been estimated that roughly 10% of the population have immunoglobin E antibodies to common inhalant molds. About half of these individuals are predicted to have, at some time, allergic symptoms as a consequence of exposure to fungal allergens.
Cause and Risk Factors When airborne allergens such as mold enter the body of a person with a sensitized immune system, they trigger antibody production (IgE) in a hypersensitive response. Part of the immune response consists of the release of histamine and other chemicals, frequently causing itching and swelling in affected tissues, mucus production, and in serious cases, hives and rashes, as well as other symptoms. Due to the nature of environmental allergens like mold, most come in contact with the skin or eyes, or are inhaled, thus causing a reaction in these areas.
The key to reducing symptoms is to reduce humidity in the home. Excess humidity (over 60%) can accelerate mold growth. Ways to reduce the level of humidity in the home include heating and dehumidifying basement areas, leave a light on in damp closets, ventilate crawl spaces, vent the clothes dryer to the outside, and reduce the number of house plants and terrariums. Other steps to reduce the level of mold in the home include removal of household items that tend to harbor mold (such as old books, plants, and carpets), painting of damp areas with mold-inhibiting paint, removing damp clothes from the washing machine immediately and dry, and keeping bathroom walls dry and mold-free through bathroom venting and cleaning.