Occupational allergic contact dermatitis diagnosed by a systematic stepwise exposure assessment of allergens in the work environment

Abstract

Information on the presence of contact allergens and irritants is crucial for the diagnosis of occupational contact dermatitis. Ingredient lists and Material Safety DataSheets (MSDSs) may be incomplete. To evaluate the workability of a systematic exposure assessment in consecutive patients with suspected occupational contact dermatitis, and to study how it could potentially aid correct diagnostic classification. A tool for systematic stepwise assessment of exposures in the work environment was developed, consisting of six steps spanning medical history and workplace visits. The programme included 228 consecutive patients diagnosed with occupational contact dermatitis; all patients underwent a clinical examination, the stepwise exposure assessment, and extensive patch and prick testing. Of the participants, 48.2% were classified as having occupational allergic contact dermatitis. The diagnosis was made at the stepwise exposure assessment for 50.0% of patients at Step 1 (medical history) and for 34.5% at Step 2 (ingredient labelling/MSDS). We found 132 different occupational allergens of relevance to the patients' eczema, of these, 78.0% were allergens not included in the European baseline series. Systematic stepwise exposure assessment provides information that results in the identification of occupational allergies caused by allergens not included in the European baseline series in a substantial number of patients.