Assessment of the Mathias Criteria for Establishing Occupational Causation of Contact Dermatitis

Background: Dermatoses account for up to 30% of occupational diseases. Of these, 90% correspond to contact dermatitis, a disease associated with a marked economic burden and considerably impaired quality of life. In 1989, Toby Mathias proposed 7 criteria to assess the relationship between contact dermatitis and occupation. Objective: To assess the Mathias criteria for establishing occupational causation of contact dermatitis in patients with dermatoses. Materials and methods: This was a descriptive study of 103 patients with dermatoses, attended consecutively between January and March of 2009 in the immunology and skin allergy department of the Parc de Salut Mar, Barcelona, Spain. The diagnosis of an occupational cause of the skin complaint by a specialist after interviewing the patient was correlated with diagnosis according to the Mathias criteria, applied by an independent specialist. Descriptive and inferential statistics were calculated. Results: An occupational cause was identified in 13 patients according to the Matthias criteria and in 12 according to the judgment of the dermatologist. The sensitivity for the Mathias criteria was 100% and the specificity was 98.90%, with a positive predictive value of 92.31% and a negative predictive value of 100%. The prevalence of occupational contact dermatitis was 11.65%. Conclusions: The Mathias criteria show a high validity and diagnostic yield, making them useful for establishing occupational causation of contact dermatitis. We believe that application of these criteria would help improve diagnostic and prognostic accuracy in occupational contact dermatitis.