title: Childhood allergic asthma is not a single phenotype.
abstract: OBJECTIVE
  IgE-mediated allergic asthma phenotype appears to be heterogeneous. We set out to define distinct allergic phenotypes by unsupervised cluster analysis.
  
  
  METHODS
  A total of 18 variables were analyzed: sex and age, eczema and food allergy, asthma duration, asthma severity and control, severe exacerbations, total IgE level, allergic sensitization, fractional exhaled nitric oxide, and functional parameters. Clusters obtained were cross-tabulated with environmental parameters.
  
  
  RESULTS
  Four clusters were identified in 125 children (average age 8.9 years): (1) 57 children constituted the "House dust mite Sensitization and Mild Asthma" cluster, 98% of these were monosensitized and had mild asthma (74%); (2) 12 children had "Pollen Sensitization with Severe Exacerbations," 92 % with severe exacerbations and pollen sensitization; (3) 20 children had "Multiple Allergies and Severe Asthma," with 95% having moderate to severe asthma, and a significantly decreased forced expiratory flow rate at 25%-75% of forced vital capacity, 100% had eczema and higher values of IgE (1123 kU/L) and fractional exhaled nitric oxide (67 ppb) (this cluster was associated with molds at home [P = .004]); and (4) 36 children had "Multiple Allergic Sensitizations and Mild Asthma," 97% of these with multiple sensitizations and 100% mild asthma.
  
  
  CONCLUSIONS
  The identification of 2 novel severe allergic asthma phenotypes "Pollen Sensitization with Severe Exacerbations"and "Multiple Allergies and Severe Asthma" could lead to specific targeted treatment.
authors.affiliation: Asthma and Allergy Center, Hôpital d'Enfants Armand-Trousseau, Université Pierre et Marie Curie, Paris, France. Electronic address: jocelyne.just@trs.aphp.fr.
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Just
authors.affiliation: Laboratory of Statistical Theories and Applications, Université Pierre et Marie Curie, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Saint-Pierre
authors.affiliation: Asthma and Allergy Center, Hôpital d'Enfants Armand-Trousseau, Université Pierre et Marie Curie, Paris, France.
authors.forename: Rahele
authors.initials: R
authors.lastname: Gouvis-Echraghi
authors.affiliation: Asthma and Allergy Center, Hôpital d'Enfants Armand-Trousseau, Université Pierre et Marie Curie, Paris, France.
authors.forename: Yacine
authors.initials: Y
authors.lastname: Laoudi
authors.affiliation: Asthma and Allergy Center, Hôpital d'Enfants Armand-Trousseau, Université Pierre et Marie Curie, Paris, France.
authors.forename: Layde
authors.initials: L
authors.lastname: Roufai
authors.affiliation: Laboratory of Public Health and Environment, Paris Descartes, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Momas
authors.affiliation: Epidemiology of Allergic and Respiratory diseases (EPAR) Department, UMR-S 707 INSERM & UPMC, Paris, France.
authors.forename: Isabella
authors.initials: I
authors.lastname: Annesi Maesano
mesh_terms: D000485:Allergens / Q000276:immunology; D001249:Asthma / Q000145:classification / Q000235:genetics* / Q000276:immunology*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype; D012720:Severity of Illness Index
chemical_list: D000485:Allergens