Purpose: Ortho-phthalaldehyde (Cidex OPA) is a commonly used solution for rapid sterilization of flexible endoscopic equipment. We report two cases of anaphylaxis following cystoscopy with endoscopes sterilized with this agent. Only a handful of such reactions have been reported in the published literature, the majority of which are in the bladder cancer population undergoing surveillance cystoscopy.
Patients and methods: We reviewed the clinical presentation of two cases of anaphylaxis following flexible cystoscopy with instruments sterilized with ortho-phthalaldehyde. We further describe their subsequent evaluation by an allergy and immunology specialist who performed skin testing to confirm a suspected ortho-phthalaldehyde allergy.
Results: Both patients were skin test positive to ortho-phthalaldehyde antigen. As a result, sterilization techniques for our flexible endoscopes has been altered. To date, no further anaphylactic reactions have occurred in our bladder cancer patients, including the two cases presented herein following subsequent cystoscopic evaluations.
Conclusions: Ortho-phthalaldehyde-sterilized cystoscopes have been associated with anaphylactic reactions in a small number of patients who have undergone repeated cystoscopy. The manufacturer has already made recommendations to avoid this agent in bladder cancer patients. It may be prudent to extend this practice to other populations undergoing repeat cystoscopy.