Allergic contact dermatitis caused by isobornyl acrylate in the Enlite glucose sensor and the Paradigm MiniMed Quick-Set insulin infusion set.

Background The FreeStyle Libre glucose sensor has caused many cases of allergic contact dermatitis, and isobornyl acrylate (IBOA) in this sensor has been identified as one of the culprit allergens. Objectives To report on the presence of IBOA in devices produced by Medtronic, namely, Enlite sensor and insulin infusion set Paradigm MiniMed Quick-set. Patients and Methods Five patients reacting to the glucose sensor Enlite and/or the insulin infusion set Paradigm MiniMed Quick-set observed in three clinics (two Belgian and one Swedish) were patch tested with the baseline and other series, as well as with IBOA; four of them also with pieces of adhesive patches from the devices, and two with a thin layer chromatogram of Enlite glucose sensor extracts. Gas chromatography-mass spectrometry (GC-MS) analyses were performed. Results Four patients reacted to IBOA and one to colophonium, a known allergen in Enlite, and three to the adhesive part of the sensor or the insulin infusion set. IBOA was identified in the sensor by GC-MS, and its presence was indicated in the infusion set. Conclusions IBOA is a contact allergen in Enlite glucose sensor, and likely also in the infusion set. Therefore, these devices are not suitable alternatives for patients sensitized to the FreeStyle Libre sensor.