title: Atopy patch test--reproducibility and elicitation of itch in different application sites.
abstract: We evaluated the reproducibility of atopy patch test reactions and the quality and quantity of itch in 16 patients with atopic eczema and a history of a positive atopy patch test reaction, comparing three different application sites. The allergen was re-applied simultaneously on both forearms and the back. Intensity and quality of pruritus were evaluated using a visual analogue scale and the Eppendorf itch questionnaire, respectively. The atopy patch test reaction was highly reproducible, occurring in 15/16 (94%) patients. Pruritus was reported by 14/16 (88%) patients. There was no significant difference in either the intensity or quality of itch between the two forearms and the back (p>0.05). The mean peak visual analogue scale itch score was comparable across all three test sites (range 28.3-31.9). Regarding quantification of test reactions, a positive reaction was more frequent on the back (94% versus 69% on the arms) and the peak atopy patch test score was higher on the back compared with the arms (right forearm, p=0.0018 and left forearm, p=0.0683). Allergens should preferably be applied on the back for the atopy patch test. However, the atopy patch test can induce atopic itch irrespective of the application site.
authors.affiliation: Department of Dermatology and Allergy, Biederstein Technical University, D-80802 Munich, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Weissenbacher
authors.forename: Theresa
authors.initials: T
authors.lastname: Bacon
authors.forename: Darren
authors.initials: D
authors.lastname: Targett
authors.forename: Heidrun
authors.initials: H
authors.lastname: Behrendt
authors.forename: Johannes
authors.initials: J
authors.lastname: Ring
authors.forename: Ulf
authors.initials: U
authors.lastname: Darsow
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens; D003876:Dermatitis, Atopic / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D008297:Male; D010147:Pain Measurement; D010328:Patch Tests / Q000379:methods / Q000592:standards*; D011237:Predictive Value of Tests; D011537:Pruritus / Q000473:pathology; D015203:Reproducibility of Results; D012882:Skin Tests / Q000379:methods / Q000592:standards; D011795:Surveys and Questionnaires
chemical_list: D000485:Allergens; D007073:Immunoglobulin E