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

Background: 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

Patch test results with the European baseline series, 2019/20-joint European results of the ESSCA and the EBS working groups of the ESCD, and the GEIDAC

Background: continual analyses of patch test results with the European baseline series (EBS) serve both contact allergy surveillance and auditing the value of included allergens. Objectives: to present results of current EBS patch testing, obtained in 53 departments in 13 European countries during 2019 and 2020. Methods: Anonymised or pseudonymised individual data and partly aggregated data on demographic/clinical characteristics and patch test rest results with the EBS were prospectively collected and centrally pooled and analysed. Results: in 2019 and 2020, 22 581 patients were patch tested with the EBS. Sensitization to nickel remained most common (19.8 [19.2-20.4]% positivity [95% confidence interval]). Fragrance mix I and Myroxylon pereirae yielded very similar results with 6.80 (6.43-7.19)% and 6.62 (6.25-7.00)% positivity, respectively. Formaldehyde at 2% aq. yielded almost one percentage point more positive reactions than 1% concentration (2.49 [2.16-2.85]% vs. 1.59 [1.33-1.88]); methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and MI alone up to around 5% positives. Among the new additions, propolis was most commonly positive (3.48 [3.16-3.82]%), followed by 2-hydroxyethyl methacrylate (2.32 [2.0-2.68]%). Conclusion: ongoing surveillance on the prevalence of contact sensitization contributes to an up-to-date baseline series containing the most frequent and/or relevant contact sensitizers for routine patch testing in Europe

Patch testing during the COVID-19 pandemic: recommendations of the AEDV's Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC)

Con el progresivo control de la pandemia por SARS-CoV-2, los miembros del Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea (GEIDAC) realizan una propuesta sobre cuáles van a ser los requisitos, las limitaciones y los condicionantes para reanudar el servicio en las unidades de dermatitis de contacto en un escenario en el que se presume la persistencia del virus, con episodios ocasionales o estacionales de exacerbación. Se aconseja ajustar el número de pruebas epicutáneas (PE) a las posibilidades de cada centro y la revisión de los casos en lista de espera para priorizar a los pacientes en función de la gravedad y la urgencia. Se ofrecerán, si es factible, métodos telemáticos para los documentos relativos a las PE (información, pautas, documentos de consentimiento informado). De estar disponible, puede ofrecerse la opción de realizar una primera visita telemática. Igualmente, en pacientes seleccionados puede llevarse a cabo una televisita en las visitas de lectura a través de imágenes realizadas por el paciente o mediante una videovisita que permita visualizar el resultado de la exploración. Estas acciones permitirán reducir el número de visitas presenciales, aunque no el tiempo dedicado y asignado al facultativo para los actos médicos. Todas estas recomendaciones son sugerencias y se adaptarán a los requisitos y a las posibilidades de cada centro sanitario

Contact sensitization to limonene and linalool hydroperoxides in Spain: a GEIDAC* prospective study.

Limonene and linalool are common fragrance terpenes widely used in cosmetic, household and hygiene products. Their primary oxidation products formed after air exposure, the hydroperoxides, have been recognized as important contact haptens. To investigate the prevalence of contact allergy to hydroperoxides of limonene (Lim-OOHs) and hydroperoxides of linalool (Lin-OOHs) in Spain, and to define the optimal concentration for screening in consecutive patients. Three different concentrations of Lim-OOHs (0.1%, 0.2% and 0.3% pet.) and Lin-OOHs (0.25%, 0.5% and 1.0% pet.) were simultaneously tested in 3639 consecutive patients at 22 departments of dermatology in Spain. Lim-OOHs at 0.1%, 0.2% and 0.3% yielded positive patch test reactions in 1.4%, 3.4% and 5.1% of the tested patients, respectively; and Lin-OOHs at 0.25%, 0.5% and 1.0% yielded positive reactions in 1.3%, 2.9% and 4.9% of the tested patients, respectively. Few irritant (1.5-1.9%) and doubtful reactions (0.4-0.5%) to both terpene hydroperoxides were registered at the highest concentrations tested. Lim-OOHs and Lin-OOHs can be considered as common causes of contact allergy, and their inclusion in an extended baseline patch test series therefore seems to be appropriate. The patch test preparations of Lim-OOHs 0.3% pet. and Lin-OOHs 1.0% pet. are useful tools for screening of contact sensitization