December 12th, 2017
Dust mites, cockroaches, cats, dogs and other animals, mold, and cigarette smoke all contribute to the etiology of atopic asthma. Decreasing exposure to these factors can reduce the symptoms of active disease. House dust mites are found in 99% of homes, and cat and dog antigens are found in 100% of homes — even in those without resident pets. In addition, mold spores and, in houses of lower socioeconomic groups, cockroach antigens, are frequently found.Acaricides, chemicals that kill mites, are troublesome because of their potential toxicity. Tannic acid, a protein denaturing agent commonly found in tea, has been shown to reduce allergen levels in house dust. Individuals who have never had a cat may become allergic by exposure to cat allergen from other sources. Cat owners with allergies to their pets are frequently unwilling to recognize a causal relationship and give up the cat.Although dogs can be a potent source of allergens, most studies have reported that children have fewer symptoms as a result of exposure to dog allergens than cat allergens. Passive smoke exposure from parents who smoke is associated with respiratory symptoms in infants and toddlers. Controlled studies have proven that measures to control environmental factors in asthma — such as vinyl zippered covers on bedsheets, HEPA filters on air vents, and removal of carpets from floors or pets from the home — can be effective in reducing the number of asthmatic episodes and in reducing the overall incidence of asthma.