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.
From the *Northwestern University Medical Center, Chicago, IL; †Department of Health, Research Institute for Tropical Medicine, Muntinlupa, Philippines; and §University of Illinois, Urbana-Champaign, IL.
Address reprint requests to Andrew Scheman, MD, Northwestern University Medical Center, 1535 Lake Cook Rd, Suite 401, Northbrook, IL 60062. E-mail: firstname.lastname@example.org.
The authors have no funding or conflicts of interest to declare.