Contact dermatitis caused by glucose sensors—15 adult patients tested with a medical device patch test series

Abstract

Background Several cases of allergic contact dermatitis (ACD) to the glucose sensor FreeStyle Libre have been reported. Isobornyl acrylate (IBOA) and N,N‐dimethylacrylamide (DMAA) are known culprit allergens. Objectives To evaluate patients with suspected ACD to FreeStyle Libre in a standardized manner, present causative allergens, and assess patient‐reported implications. Methods A total of 15 patients with suspected ACD to FreeStyle Libre were patch tested with the Swedish baseline series and a new medical device series. IBOA and DMAA were tested at 0.1% and 0.3% in petrolatum (pet.). Readings were performed on day (D) 3 and D7. Background data, details on skin reactions, and associated implications were assessed using a questionnaire. Results Thirteen patients were sensitized to IBOA and four to DMAA. Two positive reactions to IBOA and one to DMAA were seen only at 0.3% concentration on D7. Median duration of sensor use before dermatitis onset was 6 months. Half the number of the patients took precautions in everyday life due to sensor‐related skin reactions. Six patients discontinued sensor usage. Conclusions Patients with suspected ACD to glucose sensors should be evaluated with a relevant patch test series containing IBOA and DMAA. Adding the 0.3% pet. concentration is recommended. The reading on D7 is necessary.

Concomitant positive patch test reactions in FreeStyle‐allergic patients sensitized to isobornyl acrylate

“…As we performed a retrospective review of patch tested patients, we were, unfortunately, not able to re‐test a new PEA 0.1% patch test preparation, based on the re‐acquired and purer PEA raw material. Notwithstanding that no PEA, nor any of its oligomers, could be detected in any of the diabetes devices analyzed (n = 6), some devices might still contain it; 19,20 hence, its inclusion in a medical device series seems justified 12 . Future investigations will undoubtedly shed more light on the potential relevance this acrylate may have in ACD from medical devices.…”

“…Although it might be argued that the 0.1% pet. preparation of IBOA might underestimate sensitization to this chemical, 12 we have always used (from 2016 to date) this same test concentration, indicating that the “relative” decline in sensitization may truly represent a decreased overall sensitization rate. In Belgium, some of our patients sensitized to IBOA are now able to use newer, IBOA‐free versions of FL (data on file), but, as shown by the current report, in 2019 patients were often still affected by primary sensitization to IBOA, due to its presence in this particular glucose sensor.…”

“…Alternatively, some weakly sensitized patients might have been missed, as we did not patch test IBOA in a higher concentration (eg, 0.3% pet. ), nor were patients systematically recalled to the clinic for a reading on D7 12 …”

Patch testing and diagnosis when suspecting allergic contact dermatitis from medical devices

“…12 When the amount of each patch test preparation applied on the chamber is standardized, the patch test concentration and the molecular weight of the tested substance are the decisive factors determining the number of molecules/cm 2 . In a recent study, 13 15 patients with suspected ACD caused by FreeStyle Libre were patch tested with IBOA and DMAA, both at 0.1% and 0.3%, respectively. Thirteen patients were sensitized to IBOA, with 2 of the patients 4.…”

Intense skin reaction to a new glucose monitoring and insulin pump system

“…The patient was patch tested with our baseline series and a special medical device series 7 . Patch testing was also performed with pieces of the adhesive patches removed from the sensor and the insulin reservoir and with extracts of different materials in the sensor and insulin reservoir.…”