The European baseline series in 10 European Countries, 2005/2006 – Results of the European Surveillance System on Contact Allergies (ESSCA)

Background: Continual surveillance based on patch test results has proved useful for the identification of contact allergy. Objectives: To provide a current view on the spectrum of contact allergy to important sensitizers across Europe. Patients/Methods: Clinical and patch test data of 19 793 patients patch tested in 2005/2006 in the 31 participating departments from 10 European countries (the European Surveillance System on Contact Allergies' (ESSCA) www.essca‐dc.org ) were descriptively analysed, aggregated to four European regions. Results: Nickel sulfate remains the most common allergen with standardized prevalences ranging from 19.7% (central Europe) to 24.4% (southern Europe). While a number of allergens shows limited variation across the four regions, such as Myroxylon pereirae (5.3–6.8%), cobalt chloride (6.2–8.8%) or thiuram mix (1.7–2.4%), the differences observed with other allergens may hint on underlying differences in exposures, for example: dichromate 2.4% in the UK (west) versus 4.5–5.9% in the remaining EU regions, methylchloroisothiazolinone/methylisothiazolinone 4.1% in the South versus 2.1–2.7% in the remaining regions. Conclusions: Notwithstanding residual methodological variation (affecting at least some ‘difficult’ allergens) tackled by ongoing efforts for standardization, a comparative analysis as presented provides (i) a broad overview on contact allergy frequencies and (ii) interesting starting points for further, in‐depth investigation.