A major outbreak of asthma associated with a thunderstorm : experience of accident and emergency departments and patients characteristics

Abstract Objective : To investigate the time course of an epidemic of asthma after a thunderstorm, characteristics of patients affected, and the demand on emergency medical resources. Design : Study of registers and records in accident and emergency departments and questionnaire to staff. Setting : London area. Subjects : All patients presenting at 12 accident and emergency departments with asthma or other airways disease. Main outcome measures : Numbers of patients, clinical features, information on shortage of resources—equipment, drugs, and staff. Results : The epidemic had a sudden onset on 24 June 1994; 640 patients with asthma or other airways disease attended during 30 hours from 1800 on 24 June, nearly 10 times the expected number. Over half (365) the patients were aged 21 to 40 years. A history of hay fever was recorded in 403 patients; for 283 patients this was the first known attack of asthma; a history of chronic obstructive airways disease was recorded in 12 patients. In all, 104 patients were admitted (including five to an intensive care unit). Several departments ran out of equipment or drugs, called in additional doctors, or both. Conclusions : This study supports the view that this epidemic was larger than previously reported epidemics and the hypothesis that “thunderstorm associated asthma” is related to aeroallergens. Demands on resources were considerable; a larger proportion of patients needing intensive care would have caused greater problems. Key messages Key messages People affected by thunderstorm associated asthma are characteristically young atopic adults who either are not known to have previously had asthma or are asthmatic but probably do not have steroid inhaler prophylaxis Thunderstorm associated asthma seems to have had a benign course in most patients in this epidemic, but many patients presenting to accident and emergency departments should not induce complacency in the treatment of acute asthma This kind of “major incident” puts a strain on emergency medical services in a way not usually anticipated because all hospitals in an area may be affected