Octylisothiazolinone is a biocide that has been reported as a moderate, but rare contact allergen.
To investigate the occurrence of octylisothiazolinone contact allergy and allergic contact dermatitis diagnosed and registered in the Allergen Bank at Odense University Hospital during the past 20 years. Octylisothiazolinone has been used for targeted testing only.
All octylisothiazolinone-patch test results registered in the Allergen Bank between January 1992 and February 2012 were analyzed.
A total of 20 out of 648 patients patch tested with octylisothiazolinone had positive reactions. The majority of the patients (90%) with relevant sensitizations to octylisothiazolinone had been exposed in occupational settings and most patients were painters.