Indoor Allergens Associated with Asthma Morbidity

Recently, evidence has been presented that relates allergen exposure to asthma morbidity. First, the majority of asthmatic children are sensitized to common inhalant allergens, as determined by radioallergosorbent test and skin testing, implying that they are both exposed and genetically capable of producing high levels of immunoglobulin E antibody. Several series have shown that 50-80% of children with asthma have positive RAST or skin tests.^1-3 The exception is asthmatic infants younger than 3 years, where less than 40% are sensitized,^4-6 generally to food allergens and house dust mite.⁽⁶⁾ A second line of evidence is that acute asthma can be induced in sensitized asthmatics by the specific antigen in bronchoprovocation tests.⁽⁷⁾ Chronic asthma severity,^(1,2,8-10) and nonspecific airway hyperresponsiveness^(8-11) can be related to atopy; the frequency of attacks requiring emergency room treatment^(12-15) can also be shown to increase with environmental exposure to the specific antigen. Finally, avoidance of specific allergens can decrease chronic disease activity.^(16,17) This evidence suggests that it is clinically important to evaluate every child with asthma for the presence of allergy and to include allergy intervention measures in a treatment plan when indicated.