title: Methacholine challenge testing is superior to the exercise challenge for detecting asthma in children.
abstract: BACKGROUND
  Exercise-induced bronchoconstriction occurs in a large proportion of children with asthma.
  
  
  OBJECTIVE
  To compare the predictive value of methacholine challenge testing (MCCT) and the exercise treadmill challenge (ETC) for detecting asthma in children with postexercise symptoms.
  
  
  METHODS
  This was a prospective study of children 10 to 18 years old with postexercise symptoms. During asthma diagnosis, they underwent MCCT and ETC. There were 2 study visits. All subjects underwent ECT at visit 1 and MCCT 1 week later at visit 2.
  
  
  RESULTS
  One hundred one children were included; 62.9% had a history of atopy, and asthma was confirmed in 43.6%. MCCT showed 90.9% sensitivity, 82.5% specificity, 80.0% positive predictive value, and 92.2% negative predictive value; the respective values for ECT were 77.3%, 68.4%, 65.4%, and 79.6%. Positive MCCT results showed significantly higher sensitivity and higher positive predicative value in the diagnosis of asthma in children with postexercise symptoms compared with a 10% decrease in forced expiratory volume in 1 second for ECT (P = 0.034). Conducting MCCT during asthma diagnosis confirmed asthma in an additional 24.3% of children with exercise-induced symptoms. With a cutoff level at 17% of forced expiratory volume in 1 second for ECT, the discrepancy was decreased and reasonable values for sensitivity, specificity, positive predictive value, and negative predictive value were attained (61.0%, 77.1%, 69.4%, and 69.8%, respectively).
  
  
  CONCLUSIONS
  A large number of school children with asthma and postexercise symptoms could have positive MCCT and negative ECT findings. Untreated asthma in children with exercise-induced bronchoconstriction could cause them to be discharged from physical education classes.
  
  
  BACKGROUND
  www.ClinicalTrials.gov, identifier NCT01798823.
authors.affiliation: Department of Pediatrics and Allergy, Medical University of Lodz, Lodz, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Zaczeniuk
authors.affiliation: Department of Pediatrics and Allergy, Medical University of Lodz, Lodz, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Woicka-Kolejwa
authors.affiliation: Department of Social and Preventive Medicine, Medical University of Lodz, Lodz, Poland.
authors.forename: Wlodzimierz
authors.initials: W
authors.lastname: Stelmach
authors.affiliation: Department of Pediatrics and Allergy, Medical University of Lodz, Lodz, Poland.
authors.forename: Daniela
authors.initials: D
authors.lastname: Podlecka
authors.affiliation: Department of Pediatrics and Allergy, Medical University of Lodz, Lodz, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Jerzyńska
authors.affiliation: Department of Pediatrics and Allergy, Medical University of Lodz, Lodz, Poland. Electronic address: alergol@kopernik.lodz.pl.
authors.forename: Iwona
authors.initials: I
authors.lastname: Stelmach
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D016085:Bronchoconstrictor Agents / Q000008:administration & dosage; D002648:Child; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage; D011237:Predictive Value of Tests
chemical_list: D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride