Evaluation of Nickel Allergic Reactions to the Essure Micro Insert: Theoretical Risk or Daily Practice?

STUDY OBJECTIVE: To evaluate whether de novo development of nickel sensitization is related to placement of the Essure device, and to evaluate whether the grade of reaction to nickel increased after device placement in patients with a confirmed nickel allergy. DESIGN: Prospective cohort study (Canadian Task Force classification II-2). SETTING: Two nonacademic training hospitals in The Netherlands. PATIENTS: Healthy women of childbearing age desiring permanent sterilization. INTERVENTIONS: At least 72 hours before Essure sterilization, each patient received 2 patches, 1 patch with a nickel solution in 5% petrolatum and 1 control patch. In addition, the patient was asked to complete a questionnaire on allergy-related symptoms. The patch test was scored according to the criteria for contact dermatitis of Devos and Van Der Valk. At 3 months after Essure sterilization, the patch test and the questionnaire were repeated. MEASUREMENTS AND MAIN RESULTS: All 169 patients underwent Essure sterilization and completed the patch test cycle. There were no statistically significant changes in patch test results and allergy-related symptoms after sterilization. Before sterilization, 29% of the patients had a positive patch test and 1.8% also showed a positive reaction to the control patch. Only 20.7% of the patients had a history of allergic reactions to nickel. After sterilization, 29% had a positive patch test and 0.6% also showed a positive reaction to the control patch. Among the patients with a positive patch test before sterilization, the grade of reaction did not increase after sterilization. Moreover, these patients did not exhibit any increase in allergy-related symptoms. Among 4 patients with a previous negative patch test, 2 developed a grade 1 reaction and 2 developed a grade 2 reaction after sterilization. Two of these 4 patients had a history of allergic reactions to nickel before sterilization despite a negative patch test. After sterilization, these 4 patients exhibited no increase in allergy-related symptoms. CONCLUSION: There were no statistically significant changes in nickel patch test results and allergy-related symptoms after Essure sterilization. Furthermore, among the patients with a positive patch test before Essure sterilization, the grade of reaction did not increase after sterilization. These results indicate that Essure sterilization likely is not related to nickel sensitization.