Nickel dermatitis from earrings 15 years after EU directive implementation: a clinical-epidemiological study and a market survey in Rome, Italy

Background Nickel (Ni) dermatitis remains a highly prevalent allergic condition in Italy. There is a continuous need for clinical and epidemiological surveillance to evaluate whether or not European Ni Directive has been effective in contact allergy prevention. Objectives To assess the prevalence of Ni dermatitis among patch-tested patients and self-interviewed school students and to analyse Ni release from earlobe jewellery. Methods Results of patch tests performed in 2006-2007, 2015-2016 and 2017-2018 were retrieved. A questionnaire was compiled by 315 secondary school students. Ni release from earring parts was analysed with the EN1811:2015 method. Results A significant time trend of decreasing Ni positivity from 2006-2007 to 2017-2018 was observed both in the overall population (44.1% in 2006-2007, 33.0% in 2015-2016, 31.6% in 2017-2018, P < 0.0001) and in female patients (P < 0.0001). Conversely, change was not significant in males (P = 0.16). Decrease was significant for all age groups, except for those aged >60 years (P = 0.51). Among 242 students who reported earring use, 130 (54%) reported symptoms at earlobes, mostly associated with jewellery of materials other than gold and silver (59% of those with earlobe symptoms). Ni release exceeded the migration limit in 4/21 (20%) earring parts. Conclusions A high prevalence of Ni dermatitis and earlobe symptoms were found in Rome. A decreasing time trend was noted, with a significant decline in Ni sensitivity compared to the situation observed right after Ni Directive implementation. This most likely represents the consequence of reduced Ni content in earring parts, although a major care in the use of Ni-containing objects could contribute to explain these findings.