A reaction to the adhesive tape on bandages is due to contact dermatitis, according to Daniel More, M.D. Characterized as an itchy red rash in the shape of the bandage, contact dermatitis is caused by an allergic reaction to the adhesive, latex or, in some cases, medication applied to the bandage. Bandages most commonly use acrylate adhesives, including methacrylates and epoxy diacrylates, which cause a reaction in half of users.
Once a bandage is removed, the rash typically goes away on its own in a few days, according to Dr. More. In some cases, however, the body remembers where the allergic reaction occurred, and when exposed to the allergen again, a rash may appear in the same place a bandage was previously applied.
Typically a mild reaction, a contact dermatitis rash is diagnosed both visually as well as with patch testing in a doctor's office, according to Dr. More. The advantage of patch testing is that it identifies the actual compound causing the allergic reaction, making it easier to avoid it in the future. A contact dermatitis rash requires little treatment; however, an over-the-counter topical corticosteroid, such as hydrocortisone cream, is effective in relieving the itching. More powerful topical creams are available by prescription.