Living with allergies and outdoor/indoor allergens
About 50 million Americans live with allergies-to pollens, animal danders, latex, fragrances, foods, drugs, and other substances-that cause them to alter their lifestyles. Most people can reduce exposure to allergens enough to lessen symptoms.
Outdoor Allergens
The primary outdoor allergens are pollens and molds. Pollen is the powdery and often microscopic granules that are the male cells of plants. The plant disperses pollen into the air, which carries it to other plants. The dusting of pollen on plants of the same species fertilizes them, permitting them to propagate. The pollens most likely to cause a HYPERSENSITIVITY REACTION are grasses and trees. Tree pollens are highest in early spring and grass pollens (including weeds) are highest in early summer. Both tree and grass pollens remain high through summer and into early autumn in most regions of the United States. Molds are also microscopic, airborne substances, though correlate to weather conditions rather than seasons. Molds are highest when the weather is cool and wet. Raking leaves in the autumn is a major risk for exposure to molds.
Many weather reports include local pollen counts and mold counts. Counts that are moderate to high are likely to cause ALLERGY symptoms in people who are allergic; very high counts may cause symptoms in people who do not typically have seasonal allergies. Because pollens and molds are airborne, it is difficult to escape them. Allergists recommend ANTIHISTAMINE MEDICATIONS or DESENSITIZATION to mitigate symptoms. Staying indoors is not usually an effective or practical strategy.
Steps that may help include taking off outdoor clothing immediately upon coming indoors and washing the face, arms, hands, and other exposed areas with soap and water (showering is best). Washing the hands especially helps limit spreading pollen to the NOSE and EYE via contact. Some people can reduce their symptoms by wearing a mask over the face and nose during outdoor activities when pollen and mold counts are high. As well, pollen counts are highest in the early morning. Central air-conditioning in the home and in the car helps filter pollens and other particulates.
Being outdoors brings the risk of exposure to other allergens as well. People who are allergic to the sting of bees and wasps have a high risk of exposure during spring and summer when plants are in bloom. Wasps and related stinging insects become active in the autumn, especially in wooded areas or areas where there is mud. Contact with poison ivy, poison oak, or poison sumac can cause symptoms any time of the year, though this is more of a problem in spring and summer.
Indoor Allergens
Indoor allergens are commonly dust, insect droppings, and pet dander. Cockroach droppings are the prime cause of ALLERGIC ASTHMA in urban areas, especially in children. Cockroaches are attracted to moisture and food debris; keeping living areas dry and clean reduces the attraction. Dust mite droppings are also a significant cause of allergic ASTHMA and ALLERGIC RHINITIS. Dust mites also prefer humid environments, though their food source is the microscopic flakes of SKIN that people continually shed. These flakes accumulate in bedclothes and bed linens especially. Keeping the bedroom dry and washing sheets once a week in hot water helps reduce the dust mite population.
About 80 percent of American households have pets. About the same percentage of people who have allergies are allergic to pet dander (most often cat dander). Some studies have found animal dander is as pervasive in the indoor environment as is pollen in the outdoor environment. Desensitization is the recommendation of most allergists for people who are allergic but want to have pets. Though desensitization may take three to five years to become fully effective, it is a permanent solution. There are no pets that are “low allergy.” The length of an animal’s coat has little relationship to its ability to evoke an allergic reaction. Other measures include washing the hands and changing the clothes after handling an animal, and keeping pets out of the bedroom.
Central heating and air-conditioning are effective for controlling humidity as well as filtering the air. Central vacuum systems are also helpful because they deposit vacuumed debris outside the living area, usually into a container in the garage or basement. High-efficiency particulate air (HEPA) filters can remove many kinds of allergens from the air.
See also ALLERGEN; ALLERGY TESTING; QUALITY OF LIFE.
