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.