p-Phenylenediamine sensitization and occupation.

Background: p-Phenylenediamine (PPD) is an extreme delayed-type skin sensitizer, and is relevant in both occupational and non-occupational exposures.

Objectives: To estimate the prevalence of PPD sensitization in a population of consecutive patients with suspected allergic contact dermatitis who attended units of dermatology or occupational medicine in north-eastern Italy and to investigate the association between their PPD sensitization and occupation.

Patients/materials/methods: A total of 14,464 patients (67.6% women and 32.4% men) with suspected allergic dermatitis underwent patch testing. The associations between patch test results and occupations were studied by multivariate logistic regression analysis.

Results: In both sexes, PPD sensitization was significantly associated with hairdressing and beauty occupation [women, odds ratio (OR) 6.58, 95% confidence interval (CI) 3.76-11.50; men, OR 22.3, 95% CI 4.18-119]. In the female group, PPD sensitization was also significantly higher in professional drivers (OR 5.31, 95% CI 1.76-16.1), barmaids (OR 1.89, 95% CI 1.04-3.44), and cleaners (OR 1.82, 95% CI 1.24-2.68). In the male group, PPD sensitization was significantly higher in bakers and waiters (OR 13.0, 95% CI 1.38-123), household workers (OR 8.46, 95% CI 1.68-42.8), and printers (OR 5.68, 95% CI 1.50-21.5).

Conclusions: Our study showed that workers in several occupations may be at higher risk of developing sensitization to PPD. It is of importance to reduce possible exposure to PPD-crossreacting substances in these occupations.