ABSTRACT

Among the factors associated with precipitation of asthmatic symptoms is upper respiratory infection (URI). The association of URis with asthma is based on clinical observation (e.g., a mother presents her child to the clinic with worsening asthma symptoms "that really got worse when the child's cold started"), extensive epidemiological studies (e.g., clinical and virological work-ups prompted by increased symptoms and decreased lung function in a communitybased setting), and unique retrospective accounts in a variety of clinical settings (e.g., over 75% of children in an emergency room trial of bronchodilators note upper respiratory infection as a precipitating cause). While such observations do not establish causality, they do provide a working hypothesis for understanding one aspect of the complexities of asthma, and they help suggest opportunities and focus strategies to address a significant public health problem.