Allergic sensitisation did not affect bronchial hyper-responsiveness in children without respiratory tract symptoms.

Abstract

The potential for immunotherapy to prevent asthma development has become a hot topic. This prompted us to revisit data from an early study that examined allergic sensitisation on bronchial hyperresponsiveness (BHR) in children with and without respiratory symptoms. Unlike previous studies, it used both indirect and direct test methods. The study was conducted in Kuopio, Finland, in 1994 and 247 children (55.1% boys) with a mean age 10.5±1.7years were recruited using a school survey: 165 with lower respiratory symptoms and 82 healthy controls. Each child underwent a 6-min free-running test and a methacholine test with a cumulative dose of 4900µg. All participants underwent skin-prick tests: 127were sensitised and 120 were non-sensitised. There were no significant differences in lung function between the sensitised and non-sensitised children. However, sensitisation was associated with BHR which was measured by both the methacholine test (2400µg versus >4900µg, p<0.001) and the free-running test (-3.5% versus -2.6%, p=0.042). No such differences were observed among the healthy controls. Sensitisation was a predictor of allergic diseases, and only multisensitisation to a minimum of four allergens increased the incidence of asthma. Allergic sensitisation did not affect BHR in children without respiratory symptoms.