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.