Intolerance to topical products may be due to dermographism.

Patients with reactions to topical products may be eliciting a physical urticaria, dermographism, by rubbing. These reactions may be misinterpreted as allergic, and three cases demonstrating this phenomenon were reviewed. All patients with reactions to topical products due to dermographism improved with counseling and antihistamine therapy. Repeat open application testing confirmed the safety of previously suspect medications in two of the three cases, preventing unnecessary changes in the medication regimens and inaccurate diagnoses of medication allergy. We observe that intolerance to topical medications due to dermographism can usually be managed without extensive testing or treatment.