title: Prevalence of positive atopy patch test in an unselected pediatric population.
abstract: BACKGROUND
  In the latest decades, epidemiological studies on allergic disorders in children, including atopic dermatitis, rhinitis and asthma, demonstrated a continuous increase in prevalence. However, such studies are usually performed by questionnaires and, sometimes, by skin prick test or in vitro IgE tests, while the portion of allergy sustained by the cell-mediated mechanism is neglected, because the essential test, i.e. the atopy patch test is not performed.
  
  
  METHODS
  This cross-sectional survey studied by a specific questionnaire, skin prick test and atopy patch test, an unselected population, represented by the entire scholastic population attending a Primary school and a Junior Secondary school in the rural town of San Marco in Lamis, 12.000 inhabitants (Puglia, Italy).
  
  
  RESULTS
  Among the 456 subjects included, 78 (17.1 %) had a positive skin prick test and 57 (12.5 %) had a positive atopy patch test. In particular, 13.4 % of subjects were positive only to skin prick test and 8.8 % were positive only to atopy patch test. The allergen most frequently positive was the house dust mite, with 41 positive results to skin prick test and 55 to atopy patch test, while for pollen positive results concerned almost exclusively the skin prick test.
  
  
  CONCLUSIONS
  This survey on an unselected population of children detected a prevalence of positive results to atopy patch test not so distant from the positive results to skin prick test, and in 8.8 % of subjects the atopy patch test was the only positive test. This would suggest to add the atopy patch test in future epidemiological studies on allergy, in order to avoid to overlook the not negligible portion of patients with T-cell-mediated allergy.
authors.affiliation: Pediatric Allergy Service, ASL FG Torremaggiore, I, Rome, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Fuiano
authors.affiliation: Pediatric Allergy Service, ASL FG Torremaggiore, I, Rome, Italy.
authors.forename: Giuliana
authors.initials: G
authors.lastname: Diddi
authors.affiliation: UO "B Trambusti", Children's Hospital Giovanni XXIII, Bari, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Delvecchio
authors.affiliation: Allergy/Pulmonary Rehabilitation, ICP Hospital, 20100 Milan, Italy.
authors.forename: Cristoforo Incorvaia
authors.initials: CI
authors.lastname: C
keywords: Allergy; Asthma; Atopic dermatitis; Atopy patch test; Rhinitis; Skin prick test