title: Histamine inhalation challenge in children: a comparison of two methods.
abstract: Airway reactivity in children is often assessed using a histamine inhalation challenge test. The bronchoconstrictor agents are usually delivered by five slow inspiratory capacity (IC) maneuvers, the IC method. We compared the IC method with a tidal breathing (TB) method in 30 children; 11 were normal, six were under investigation for asthma and 13 were known asthmatics. None of the normal children responded to either method, whereas 18 out of the 19 (95%) known or suspected asthmatics responded to the TB method while only 13 out of 19 (68%) showed a significant reduction in FEV1 when the IC method was used. The concentration of histamine necessary to cause a 20% reduction in FEV1 was less for the TB method, suggesting that in children the TB method will produce airway reactivity more quickly than the IC method.
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000175:diagnosis*; D001985:Bronchial Provocation Tests / Q000379:methods*; D002648:Child; D005541:Forced Expiratory Volume; D006632:Histamine; D006801:Humans
chemical_list: D006632:Histamine