Is a local reaction (e.g., hives) to topical Neosporin a contraindication or precaution to MMR?
Because MMR and its component vaccines contain trace amounts of neomycin (25 mcg), persons who have experienced anaphylactic reactions to topically or systemically administered neomycin should not receive these vaccines. However, neomycin allergy is most often manifested as a delayed or cell-mediated immune response (i.e., a contact dermatitis), rather than anaphylaxis. In persons who have such a sensitivity, the adverse reaction to the neomycin in the vaccine is an erythematous, pruritic nodule or papule appearing 48–96 hours after vaccination. A history of contact dermatitis to neomycin is not a contraindication to receiving MMR vaccine.
