A generalized reaction to thimerosal from an influenza vaccine

Background: Thimerosal is a preservative commonly used in ophthalmic solutions, otic drops, and vaccines because of its bactericidal property. Objective: To report a case of a generalized reaction to thimerosal in a patient who received an influenza vaccine. Methods: We describe a patient who developed a generalized maculopapular eruption after receiving a thimerosal-containing influenza vaccine. Patch testing was performed to determine if there was an allergy to thimerosal. Results: Patch testing confirmed a T-cell-mediated sensitivity to thimerosal. Conclusions: Physicians need to be aware that thimerosal is found in many products, including vaccinations. Clinicians should also be aware that allergic reactions occur with exposure to thimerosal even in vaccines. To our knowledge, this is the first case report in the literature of a generalized reaction to thimerosal from an influenza vaccine.