Uter, WolfgangGiménez Arnau, Anna MariaGEIDAC2022-08-312022-08-312022Uter W, Wilkinson SM, Aerts O, Bauer A, Borrego L, Buhl T et al. European patch test results with audit allergens as candidates for inclusion in the European Baseline Series, 2019/20: Joint results of the ESSCA A and the EBS B working groups of the ESCD, and the GEIDAC C. Contact Dermatitis. 2022 May;86(5):379-89. DOI: 10.1111/cod.140590105-1873http://hdl.handle.net/10230/53959Background: In 2019, a number of allergens (haptens), henceforth, "the audit allergens," were considered as potential additions to the European Baseline Series (EBS), namely, sodium metabisulfite, 2-bromo-2-nitropropane-1,3-diol, diazolidinyl urea, imidazolidinyl urea, Compositae mix II (2.5% or 5% pet), linalool hydroperoxides (lin-OOH), limonene hydroperoxides (lim-OOH), benzisothiazolinone (BIT), octylisothiazolinone (OIT), decyl glucoside, and lauryl glucoside; Evernia furfuracea (tree moss), was additionally tested by some departments as well. Objectives: To collect further data on patch test reactivity and clinical relevance of the audit allergens in consecutive patients across Europe. Methods: Patch test data covering the audit allergens in 2019 and 2020 were collected by those departments of the European Surveillance System on Contact Allergies testing these, as well as further collaborators from the EBS working group of the European Society of Contact Dermatitis (ESCD), and the Spanish Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea. As patch test outcome, reactions between day (D) 3 and D5 were considered. Results: Altogether n = 12 403 patients were tested with any of the audit allergen. Positive reactions were most common to lin-OOH 1% pet. (8.74% [95%CI: 8.14-9.37%]), followed by lin-OOH 0.5% pet., and lim-OOH 0.3% pet (5.41% [95% CI: 4.95-5.89%]). Beyond these terpene hydroperoxides, BIT 0.1% pet. was the second most common allergen with 4.72% (95% CI: 4.2-5.28%), followed by sodium metabisulfite 1% pet. (3.75% [95%CI: 3.32-4.23%]) and Compositae mix 5% pet. (2.31% [95% CI: 1.84-2.87%]). For some allergens, clinical relevance was frequently difficult to ascertain. Conclusions: Despite many positive patch test reactions, it remains controversial whether lin- and lim-OOH should be tested routinely, while at least the two preservatives BIT and sodium metabisulfite appear suitable. The present results are a basis for further discussion and ultimately decision on their implementation into routine testing among the ESCD members.application/pdfeng© 2022 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.info:eu-repo/semantics/articlehttp://dx.doi.org/10.1111/cod.14059RRID:SCR_001905Baseline seriesBenzisothiazolinoneClinical epidemiologyContact allergyDecyl glucosidePatch testingSodium metabisulfiteSurveillanceinfo:eu-repo/semantics/openAccess