Carba Mix: A Useful Indicator of Rubber Sensitivity

Summary

The value of carba mix as a contact allergen in the European standard battery of allergens has come under question. A retrospective analysis of data from 5986 patients undergoing patch testing revealed that, had carba mix been excluded from the standard battery, 84 cases of contact dermatitis to rubber compounds would have been missed (i.e. 1.3% of all patients patch-tested). However, during the same period there were 83 false-positive reactions to carba mix (i.e. 1.3% of all patients patchtested). Carba mix is therefore a useful indicator of rubber sensitivity, although the high false-positive rate underlines the need for a degree of expertise and experience in reading patch tests.