RT Journal Article SR Electronic T1 Determinants of airway responsiveness to histamine in children JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 462 OP 467 DO 10.1183/09031936.05.00046404 VO 25 IS 3 A1 S. W. Turner A1 L. J. Palmer A1 P. J. Rye A1 N. A. Gibson A1 S. Young A1 J. Goldblatt A1 L. I. Landau A1 P. N. Le Souëf YR 2005 UL http://erj.ersjournals.com/content/25/3/462.abstract AB Increased airway responsiveness (AR) is associated with asthma, but not all individuals with increased AR have asthma. The aim of this study was to identify factors, other than physician-diagnosed asthma (PDA), which are associated with increased AR. In a longitudinal study, data were collected on atopy and lower respiratory tract illness (LRTI) in infancy, and AR (expressed as dose–response slope (DRS)), atopy, tobacco-smoke exposure and PDA in childhood. At age 6 yrs, DRS was assessed in 102 children, of whom 22 (22%) had PDA; the corresponding figures at 11 yrs of age were 176 and 29 (15%). At age 6 yrs, DRS was significantly associated with PDA, current atopy and parental smoking (n = 83). At age 11 yrs, DRS was significantly associated with PDA, current atopy and LRTI in the first six months (n = 75). There was a significant positive interaction between atopy at age 12 months and PDA age 11 yrs. In conclusion, these data suggest that factors other than asthma or atopy may determine the level of airway responsiveness in children. In children with asthma, airway responsiveness may be influenced by the early onset of atopy. The current findings may explain the inconsistent relationship between airway responsiveness and asthma.