Atopy patch testing in children with asthma and rhinitis symptoms allergic to house dust mite

The atopy patch test (APT) is generally used to assess immunoglobulin E (IgE) mediated sensitization to allergens in patients with atopic dermatitis, but its diagnostic role in children with respiratory allergy is still controversial. The aim of the study was to evaluate APT with house dust mite (HDM) in children with asthma and rhinitis symptoms allergic to HDM and its relevance to skin prick test (SPT) diameters and specific IgE levels. The study population consisted of 33 children, aged 8-16 yr (median: 12 yr) with asthma and 30 children with allergic rhinitis in the same age range (median: 11 yr). All patients had positive SPT results and high serum specific IgE levels for Dermatophagoides pteronyssinus APT was performed on back skin of all patients with 200 index of reactivity (IR)/ml of D. pteronyssinus allergen extracts in petrolatum (Stallerpatch) and evaluated at 72 h. Of 63 patients, 16 (25%) showed a positive patch test result. APT with HDM showed 30% (10/33) positivity among the patients with asthma and 20% (6/30) positivity among the patients with allergic rhinitis. APT presented no significant correlation with age, SPT diameter, serum total and specific IgE levels for D. pteronyssinus, nasal provocation test or pulmonary function test results. Patch testing with HDM may partly identify mite sensitive children with respiratory allergy. Positive APT results may imply that delayed hypersensitivity reactions play a role in children with asthma and rhinitis allergic to HDM.