Nickel, chromium and cobalt sensitization in a patch test population in north-eastern Italy (1996-2010).

Background. Sensitization to nickel, cobalt and chromium is frequent in patch test populations. The prevalence is affected by geographical and socio-cultural factors. Objectives. To investigate the temporal trend of nickel, cobalt and chromium contact sensitization between 1996 and 2010 in north-eastern Italy. Patients/methods. Nineteen thousand and eighty-eight patients (67.2% women and 32.8%men)withsuspectedallergic dermatitisunderwentpatchtestingwith theEuropean baseline series. The associations between nickel, cobalt and chromium sensitization and patient age (in quintiles) and year of patch testing were investigated by means of multivariate logistic regression analysis. Results. The prevalence of nickel sensitization decreased significantly among younger women (≤26 years), from 38.3% (1996–1998) to 31.9% (2002–2004), 28.3% (2005–2007) and 29.0% (2008–2010), whereas an increase was observed in the 36–45-year and 46–58-year age groups. The overall prevalence of chromium sensitization dropped from 10.2% (1996–1998) to 4.6% (2008–2010) among women, and from 11.3% (1996–1998) to 5.9% (2008–2010) among men. The prevalence of cobalt sensitization increasedamongyoungermen(≤26 years), from2.7%(1996–1998) to 7.3% (1999–2001), 9.6% (2002–2004), and 6.6% (2005–2007). Conclusions. Our study showed a decreasing trend of nickel sensitization (only among younger women) and of chromium sensitization in both sexes.