Changes in adhesive ingredients in continuous glucose monitoring systems may induce new contact allergy pattern

Background: Medical devices (MD) in close skin-contact for a prolonged time, such as glucose monitoring (CGM) systems, are a risk factor for contact allergy, and there has been an increase in patients using these. Correct diagnosis demands targetted testing. Objectives: We report a new allergen in a continuous CGM system in which the adhesive was changed. The allergy pattern of the patients diagnosed is reported. Methods: The three patients reported were patch tested with an MD series, own material, and possible allergens found through analysis with gas chromatography-mass spectrometry, comparing analysis from the CGM system before and after change. Results: The patients were sensitized to isobornyl acrylate (IBOA), found in previously used devices and the present CGM. Apart from IBOA, the culprit allergen was found to be 2,2 '-methylenebis(6-tert-butyl-4-methylphenol) monoacrylate. Conclusion; Allergic contact dermatitis due to CGM systems and insulin pumps are difficult to investigate and require chemical analysis. Because of the lack of information on substances used in the production, and when changes with MDs are initiated, it is difficult to advise patients, especially since they risk sensitization to several allergens. The use of MDs has increased and, thus, the need for collaboration between manufacturers, clinicians, and patient organizations.