A Comparison of Contact Allergies Among Construction and Nonconstruction Workers Attending Contact Dermatitis Clinics in Germany: Results of the Information Network of Departments of Dermatology From November 1989 to July 1993

We evaluated the data of 205 patients working in the construction industry (bricklayers, tile setters, and so on) who had been patch tested between November 1989 and July 1993 in the dermatologic hospitals joining the Information Network of Departments of Dermatology. These data were compared with those of 5,706 men tested during the same time who did not work in the building industry. The five most frequent allergens among the patients working in the construction industry were potassium dichromate (31.9%), cobalt chloride or sulfate (15.0%), nickel sulfate (8.3%), thiuram mix (7.8%) and p-phenylenediamine (7.7%). Differences in sensitization frequency between both groups were significant for potassium dichromate (31.9% versus 7.1%), cobalt salts (15.0% versus 4.9%), thiuram mix (7.8% versus 3.0%), and epoxy resin (4.7% versus 1.8%). Despite the general presumption that cobalt allergies in this branch are acquired by handling wet cement, we think that, in view of the large spectrum of contact materials in the construction industry, it is thoroughly imaginable that there are further cobalt sources that have remained undetected until now. This is why, for preventive reasons, further possible exposure hazards should be sought. The special pattern of concomitant sensitizations among patients allergic to cobalt leads to the question of whether cobalt allergy is a marker for a subpopulation of patients who generally develop contact allergies more easily.