European Surveillance System on Contact Allergies (ESSCA): Contact allergies in relation to body sites in patients with allergic contact dermatitis

BACKGROUND Analyses of the European Surveillance System on Contact Allergies (ESSCA) database have focused primarily on prevalence of contact allergies to the European baseline series; overall and in subgroups of patients. However, affected body sites have hitherto not been addressed. OBJECTIVE To determine prevalence of contact allergies for distinct body sites in patients with allergic contact dermatitis (ACD). METHODS Analysis of data collected by ESSCA (www.essca-dc.org) in consecutively patch tested patients, 2009-2014, in 8 European countries. Cases were selected based on the presence of minimally one positive patch test to the baseline series, and a final diagnosis of ACD attributed to only one single body site. RESULTS N=6,255 cases were analyzed. The head and hand were the most common single sites ACD was attributed to. Differences between countries were seen for several body sites. Nickel, fragrance mix I, cobalt and methylchloroisothiazolinone/methylisothiazolinone were the most frequent allergens reported for various body sites. CONCLUSION Distinct allergen patterns per body site were observed. However, contact allergies were probably not always relevant for the dermatitis that patients presented themselves with. Adding possibility to link positive patch test reactions to relevance, along with affected body sites should be a useful addition to data capturing systems.