2017 Volume 11 Issue 3 Pages 227-233
Kathon CG is an isothiazolinone preservative that is widely used in hair care products, cosmetics and wet wipes. A concern recently reported is that the frequency of positive Kathon CG patch test results has been increasing. We present the case of a woman who experienced recalcitrant dermatitis on her scalp, face, upper arms and back for 5 years. In the Japanese standard allergen 2008 series, the patch test was positive for Kathon CG. Contact dermatitis caused by haircare products containing Kathon CG was suspected. The haircare products and facial cleanser that she routinely used did not cause a reaction, although they all contained Kathon CG. The skin rash was recalcitrant, with occasional flare-ups on her scalp, face and back even after discontinuing the products. We believe that the flare-ups may have been caused by the presence of Kathon CG in some other products that she routinely used.
We have investigated 15 cases with positive Kathon CG patch tests. Fourteen were in women, who had frequent cutaneous lesions on the face and hands. Atopic dermatitis detected in six of the cases was considered to have resulted from relatively frequent exposure to Kathon CG.
