INHALATION CHALLENGES WITH AGENTS CAUSING OCCUPATIONAL ASTHMA

Occupational asthma (OA) is steadily emerging as the principal cause o f respiratory disease due to the workplace environment, One of the key means to ascertain diagnosis of OA is specific inhalation challenge ( SIG) with occupational agents, This review: 1) describes the methodolo gy of SIG, with a special emphasis on procedures aimed at increasing t he safety and validity of these tests; and 2) outlines the roles of SI C in the diagnosis of OA in clinical and medicolegal assessment, epide miological studies, surveillance programmes and the investigation of t he pathophysiological mechanisms of asthma and OA, We discuss areas of future development, including the development of apparatus which allo ws exposure of subjects to low and stable concentrations of the occupa tional agent and the assessment of preventive procedures.