This age-old staple has been the cornerstone of antibacterial ointments for about 50 years. It contains three different antibiotic components, but the main offender is neomycin. Neomycin is a very well-known “sensitizer”, and the more that you use it, the greater the chance that it will cause an allergic reaction. Once you become allergic to it, you always will be…sorry about that. My patients are frequently shocked to find out that they are allergic to Neosporin because they have been using it for years. But, that’s how allergies work… it sometimes takes a long time before you start to react. There are a variety of over-the-counter antibiotic ointments that are better and safer, with significantly less risk of allergic reaction. My favorite is Polysporin, but plain old bacitracin is also a very good choice.