Uncovering allergen presence and accumulation in glucose monitoring systems: evidence of a "sponge effect" via validated GC-MS.

BACKGROUND: Despite the clinical benefits associated with the use of continuous and flash glucose monitoring systems (GMS), they are frequently associated with dermatological adverse effects, most notably allergic contact dermatitis (ACD). Chemical analysis of devices is often the only means to confirm the presence of suspected sensitizers or detect emerging allergens in these products. Although previous research efforts lead to the identification of some main allergens such as acrylates and colophony compounds, new allergens continue to emerge and the presence of known allergens in devices cannot be excluded. However, no validated quantitative analytical methods for these compounds in GMS have been reported.

RESULTS: A quantitative gas chromatography-mass spectrometry (GC-MS) method was developed and validated, with a focus on optimizing the extraction from the devices. An untargeted screening workflow was incorporated to detect additional potentially relevant allergens. Targeted analysis enabled quantification (14 compounds) or estimated abundance analysis determination (5 compounds) of relevant allergens. The method was applied to unused and used Dexcom G7 and associated adhesive patches. Different allergens were detected and quantified including isobornyl acrylate, methyl dehydroabietate, and isocyanates. Other compounds were only detected in used devices, such as cetyl alcohol, isopropyl palmitate and isopropyl myristate.

SIGNIFICANCE: The analysis revealed the presence of known and new allergens in medical devices for diabetes. Several allergens were present in unused devices, but others were detected only in used devices. These additional compounds likely accumulated from daily usage, leading to what we defined as the "sponge effect".