“…Studies of the relationship between the upper and lower airways in human subjects by means of the challenge technique are not numerous [8, 9, 11, 13, 17, 18,21,22,23,36,37,38,39,40], and those using challenge with allergen are but few [8, 13, 17, 18,21,22,23,36,37,38,39,40]. In some of these studies, the effects of nasal challenge with allergen on the bronchial responsiveness to histamine/methacholine have been investigated [18, 37, 38].…”