Primin sensitization in north-eastern Italy: a temporal trend from 1996 to 2012

BACKGROUND: Primin is the main contact allergen found in the ornamental plant Primula obconica Hance. OBJECTIVE: To analyse the temporal trend of sensitivity to primin in north-eastern Italy and to evaluate the associations with occupations in our geographical area. METHODOLOGY: From 1996 to 2012, 24 052 consecutive patients with suspected allergic contact dermatitis were patch tested in north-eastern Italy. Individual characteristics were collected through a standardized questionnaire in eight departments of dermatology or occupational medicine. RESULTS: The overall prevalence of primin sensitization was 1.9%; the prevalence was significantly higher in women (2.6%) than in men (0.5%). The Pordenone area had the higher prevalence of sensitization, which reached 6% in 1999-2001. We found a significant association between primin sensitization and household workers [odds ratio (OR) 2.3; 95% confidence interval (CI): 1.61-3.35], retired people (OR 1.8; 95%CI: 1.22-2.81), woodworkers (OR 2.1; 95%CI: 1.10-6.18), and chemical industry workers (OR 2.9; 95%CI: 1.05-8.29). CONCLUSION: Our study showed that contact allergy to primin is still relevant in north-eastern Italy. The frequency of sensitization is decreasing, but for retired and household workers it is still >4%. Our results suggest the need to promote the use of primin-free P. obconica in Italy.