title: Mannitol dry powder challenge in comparison with exercise testing in children.
abstract: BACKGROUND
  Mannitol dry powder (MDP) challenge is an indirect bronchial provocation test, which is well studied in adults but not established for children.
  
  
  OBJECTIVE
  We compared feasibility, validity, and clinical significance of MDP challenge with exercise testing in children in a clinical setting.
  
  
  METHODS
  Children aged 6-16 years, referred to two respiratory outpatient clinics for possible asthma diagnosis, underwent standardized exercise testing followed within a week by an MDP challenge (Aridol™, Pharmaxis, Australia). Agreement between the two challenge tests using Cohen's kappa and receiving operating characteristic (ROC) curves was compared.
  
  
  RESULTS
  One hundred eleven children performed both challenge tests. Twelve children were excluded due to exhaustion or insufficient cooperation (11 at the exercise test, 1 at the MDP challenge), leaving 99 children (mean ± SD age 11.5 ± 2.7 years) for analysis. MDP tests were well accepted, with minor side effects and a shorter duration than exercise tests. The MDP challenge was positive in 29 children (29%), the exercise test in 21 (21%). Both tests were concordant in 83 children (84%), with moderate agreement (κ = 0.58, 95% CI 0.39-0.76). Positive and negative predictive values of the MDP challenge for exercise-induced bronchoconstriction were 68% and 89%. The overall ability of MDP challenge to separate children with or without positive exercise tests was good (area under the ROC curve 0.83).
  
  
  CONCLUSIONS
  MDP challenge test is feasible in children and is a suitable alternative for bronchial challenge testing in childhood.
authors.affiliation: Division of Paediatric Pulmonology, Children's Hospital, St. Gallen, Switzerland. juerg.barben@kispisg.ch
authors.forename: Juerg
authors.initials: J
authors.lastname: Barben
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Kuehni
authors.forename: Marie-Pierre F
authors.initials: MP
authors.lastname: Strippoli
authors.forename: Barbara
authors.initials: B
authors.lastname: Schiller
authors.forename: Juerg
authors.initials: J
authors.lastname: Hammer
authors.forename: Daniel
authors.initials: D
authors.lastname: Trachsel
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000175:diagnosis*; D016084:Bronchoconstriction; D002648:Child; D005080:Exercise Test / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008353:Mannitol / Q000009:adverse effects; D011208:Powders; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D011208:Powders; D008353:Mannitol