title: Biphasic (early and late) asthmatic responses to exercise in children with severe asthma, resident at high altitude.
abstract: Twenty-three children with severe asthma who had been resident at high altitude for at least 3 months, considerably reduced their requirement for regular anti-asthma therapy. On a standard exercise challenge in low humidity, ten had no response, seven had isolated immediate bronchospasm and six had biphasic responses with immediate bronchospasm followed 4-10 h later by a late reaction sustained for at least 2 h. The existence of biphasic responses after exercise, similar to those observed after antigen challenge, supports the concept of mast cell involvement in exercise-induced asthma.
mesh_terms: D000293:Adolescent; D000531:Altitude; D001249:Asthma / Q000503:physiopathology*; D001250:Asthma, Exercise-Induced / Q000503:physiopathology*; D002633:Chemotaxis; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000502:physiology; D010366:Peak Expiratory Flow Rate; D005082:Physical Exertion; D010865:Pilot Projects