European Surveillance System on Contact Allergies (ESSCA): polysensitization, 2009-2014.

BACKGROUND: Polysensitization, defined as being allergic to three or more haptens from the European baseline series, is considered to reflect increased susceptibility to developing a contact allergy, and is likely to be associated with an impaired quality of life. OBJECTIVES: To evaluate the prevalences of polysensitization across Europe and to analyse factors associated with polysensitization. METHODS: Patch test data collected by the European Surveillance System on Contact Allergies (ESSCA; www.essca-dc.org) in consecutively patch tested patients from January 2009 to December 2014, comprising 11 countries and 57 departments, were retrospectively analysed. RESULTS: A total of 86 416 patients were available for analysis, showing a standardized prevalence of polysensitization of 7.02%, ranging from 12.7% (Austria) to 4.6% (Italy). Allergen pairs with the strongest association are reported for the total population, for South Europe, and for North/Central Europe. Overall, polysensitized patients showed a higher percentage of extreme (+++) positive patch test reactions than oligosensitized patients. Female sex, occupational dermatitis and age > 40 years were risk factors for polysensitization. CONCLUSIONS: The varying prevalences of polysensitization across Europe most likely reflect differences in patient characteristics and referral patterns between departments. Known risk factors for polysensitization are confirmed in a European dermatitis population.

ESSCA results with the baseline series, 2009-2012: rubber allergens.

BACKGROUND: Allergic contact dermatitis caused by rubber allergens is common, and causes significant patient morbidity. Contemporary data are important to allow appropriate preventive measures and identification of contact allergy trends. OBJECTIVES: To describe the pattern of patch test reactivity to rubber allergens, including those in the European baseline series. METHODS: Data collected by the European Surveillance System on Contact Allergies (ESSCA) network between 2009 and 2012 from 12 European countries were analysed. RESULTS: Contact allergy to thiuram mix declined over the studied time period, with an overall prevalence of 1.87%. The prevalence of allergy to carba mix was 2.29%, and was significantly increasing. Prevalence rates of sensitization to other rubber allergens were largely unchanged. Statistical analysis with the MOAHLFA index confirmed the strong links between rubber allergy and occupational hand dermatitis. CONCLUSIONS: Changing patterns of allergy to rubber additives have been identified. Inclusion of carba mix in the European baseline series may be appropriate.