BRONCHIAL PROVOCATION TESTS IN ETIOLOGIC DIAGNOSIS AND ANALYSIS OF ASTHMA

Abstract

Bronchial provocation tests in asthma and allergic alveolitis are a pragmatic means of etiologic diagnosis that also reproduce some or all of the clinical manifestations. In this respect, the test reactions provide models of the clinical disorder and are useful in interpretation of the variable history, in particular of clinical asthma. The identification of causal agents from the history, provocation tests and other methods, places the patient in the extrinsic group and, by definition, places those without such evidence in the cryptogenic (intrinsic) group. The term extrinsic asthma was previously applied mainly to asthma in atopic subjects with evidence of reagin, Ig[immunoglobulin]E antibody to the relevant allergens. Analyses of the asthmatic reactions to extrinsic agents promises to broaden the context of extrinsic asthma. Analyses can be made taking into account, with many provisos, the immunologic classification of the subject as atopic or nonatopic, the patterns of asthmatic reaction and their possible immunopathologic mechanisms. A comparison is made of asthmatic reactions in atopic and nonatopic subjects. Classification of the asthmatic reactions can be clinically relevant, because the patterns of asthmatic reaction determine how the subject is likely to respond to 3 of the main therapeutic agents for the treatment of asthma, i.e., bronchodilator drugs, cromolyn sodium and corticosteroids.