Contact Allergy Cross-reactions: Retrospective Clinical Data and Review of the Literature.

We discuss cross-reactions that can occur when a patient allergic to a specific allergen also reacts to a similar allergen. Currently, The American Contact Dermatitis Society Contact Allergy Management Program, which allows physicians to identify safe products for their patients, uses a 10% threshold to distinguish significant cross-reactors. New clinical data from a patch testing center along with previous data in the literature are analyzed to help determine whether current cross-reactor definitions are reasonable or should be altered.