Laughter-associated asthma.

This study was conducted to assess the prevalence of laughter-induced asthma, and to study any associations with asthma-related triggers and measures of disease activity, using a questionnaire-based survey of asthma subjects in both the community and on presentation to hospital. A total of 105 subjects participated, and 44 (41.9%) reported laughter-associated asthma. Exercise and laughter were strongly associated as triggers (p < 0.006), as well as molds and grass pollen (p = 0.03). It seems to be associated with poor asthma control as well, since hospital admissions are also more frequent in this group (p = 0.043). Laughter-induced asthma is strongly associated with exercise as a trigger; the mechanism remains uncertain, but better understanding of this problem may assist in controlling difficult asthma.