Current Allergy and Asthma Reports

, Volume 13, Issue 5, pp 539–544

Patch Testing for Noncontact Dermatitis: The Atopy Patch Test for Food and Inhalants

ALLERGIC SKIN DISEASES (L FONACIER, SECTION EDITOR)

DOI: 10.1007/s11882-013-0368-6

Cite this article as:
Wollenberg, A. & Vogel, S. Curr Allergy Asthma Rep (2013) 13: 539. doi:10.1007/s11882-013-0368-6

Abstract

The atopy patch test (APT) is defined as a patch test procedure to assess delayed type hypersensitivity reactions against those protein allergens known to elicit IgE-mediated type I reactions in atopic patients. This patch test procedure uses intact protein allergens instead of haptens in an optimized test setting and with a special reading key. It may be clinically useful especially for atopic dermatitis, as the currently available test procedures either target the wrong reaction type (type I and not type IV) or use the wrong allergens (haptens and not protein allergen). A positive APT reaction correlates with a positive lymphocyte transformation test and allergen-specific Th2 cells in the peripheral blood. As even small changes in the test procedure influence the sensitivity, specificity, and reproducibility of the APT, the European Task Force on Atopic Dermatitis (ETFAD) has developed a standardized APT technique: Intact protein allergens, purified in petrolatum, are applied in 12-mm-diameter Finn chambers mounted on Scanpor tape for 48 h to non-irritated, non-abraded, or tape-stripped skin of the upper back for 48 h; the evaluation of the test reaction is done after 48 and 72 h using the ETFAD reading key, assessing erythema as well as number and distribution pattern of the papules. The APT may reveal type IV sensitization in patients who are negative for the respective type I tests. Limited availability of the expensive test substances and limited reimbursement is among the factors restricting the routine use of the APT.

Keywords

Atopic dermatitis Patch test ETFAD Reading key Atopy patch test Standardization Noncontact dermatitis Inhalants Immunology 

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  1. 1.Department of Dermatology and AllergyLudwig Maximilian UniversityMunichGermany

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