The European Surveillance System of Contact Allergies (ESSCA): results of patch testing the standard series, 2004.

BACKGROUND: The European Surveillance System on Contact Allergies (ESSCA) began in 2001 as project funded by a European Union grant to monitor and evaluate contact sensitization (CS) based on clinical data collected by participating European dermatology departments. OBJECTIVES: ESSCA aims to detect trends in CS in an international patch test population, monitoring the frequency of CS to (standard series) allergens, evaluating the effectiveness of intervention (e.g. governmental regulations) and improving standardization of the patch test procedure on an international level. METHODS: In 2004, 31 ESSCA dermatology departments in 11 European countries collected patch test results and medical histories of patients tested with the European Standard Series (ESS) or a local standard allergen series using the multilingual Winalldat/ESSCA database, the German Winalldat/Information Network of Departments of Dermatology (IVDK) database or a locally created database including the items of the ESSCA 'minimal data set'. Data were sent to the ESSCA data centre where they were imported, pooled, examined for quality and subsequently analysed. RESULTS: The departments patch tested 11 643 patients with a standard series, and 44% of the patients tested positive to one or more substances of the ESS. Nickel sulphate, the fragrance mix, Myroxylon pereirae resin, cobalt chloride, potassium dichromate, methyldibromoglutaronitrile and paraphenylenediamine are (still) the most important allergens detected. Several additional substances tested on consecutive patients in some clinics were also examined. Among these allergens, propolis and Compositae mix had a relatively high CS prevalence. CONCLUSIONS: The expanding ESSCA network continues to provide up-to-date information regarding the pattern of CS diagnosed in participating departments across Europe.