Symptoms in asthmatics living in cold districts during winter

Exposure to cold is known as a potential exacerbating factor in asthmatics. However, few studies have investigated severity of symptoms during daily life in winter for asthmatics living in northern Hokkaido, the coldest region in Japan. We sent questionnaires to 126 asthmatics living in northern Hokkaido, and obtained answers from 116 patients (52 males, 64 females). Breathing difficulties during cold-air exposure were reported by 62.1% of patients. Furthermore, 19.6% of patients had experienced the need for bronchodilators following cold-air-induced attacks. Limitations to daily life in winter caused by exacerbated asthmatic symptoms were recognized by 48.3% of patients. Asthmatic exacerbation was experienced by 30% of patients in summer (May to August), compared to >35% in winter (September to April). No significant differences in results were noted between atopic and non-atopic patients. Improvements in respiratory symptoms during winter are thus necessary for better quality of life in asthmatics living in cold districts.