Sensitivity to Kathon CG: findings in 365 consecutive patients.

In the period from 1983 through 1986, 365 consecutive patients suspected as having allergic contact dermatitis were tested for reaction to Kathon CG. This test was positive in 20 of these patients: irritant responses in 7 and allergic sensitivity in 13. Provocative use testing was positive in 1 of the 3 allergic patients tested. The characteristics of this group of patients include having a mean age older than that of the general population or of our population of dermatologic patients, having histories of long-standing dermatitis, and reporting exposure to various leave-on formulations. Our rate of positive tests, 3.6%, is similar to that reported by other investigators, although sensitivity testing results differ from center to center. It is recommended that, in certain clinical situations, caution be exercised in the unsupervised use of leave-on products containing Kathon CG.