Contact Allergy to Allergens in the Swedish Baseline Series Overrepresented in Diabetes Patients with Skin Reactions to Medical Devices - A Retrospective Study from Southern Sweden.

Allergic contact dermatitis is reported among individuals using continuous glucose monitoring systems and insulin pumps. The aim of this study was to describe contact allergy patterns for allergens in the Swedish baseline series and medical device-related allergens among users. Contact allergy to baseline series allergens and isobornyl acrylate was compared between diabetes patients and dermatitis patients patch-tested at the Department of Occupational and Environmental Dermatology during 2017 to 2020. Fifty- four diabetes patients and 2,567 dermatitis patients were included. The prevalence of contact allergy to fragrance mix II and sesquiterpene lactone mix was significantly higher in diabetes patients compared with dermatitis patients. Of the diabetes patients 13.0% and of the dermatitis patients 0.5% tested positive to sesquiterpene lactone mix (p < 0.001). Of the diabetes patients 7.4% and of the dermatitis patients 2.3% tested positive to fragrance mix II (p = 0.041). Of the diabetes patients 70.4% tested positive to medical device-related allergens. Of the diabetes patients 63.0% and of the dermatitis patients 0.2% were allergic to isobornyl acrylate (p < 0.001). In conclusion, not only medical device-related contact allergies, but also contact allergy to baseline series allergens (fragrance mix II and sesquiterpene lactone mix), is overrepresented in diabetes patients who use medical devices.

New device, 'old' allergens. Allergic contact dermatitis caused by the Dexcom G7 glucose sensor.

BACKGROUND: Allergic contact dermatitis (ACD) has been reported as an adverse effect from the use of several glucose sensors and insulin pumps from different manufacturers. Isobornyl acrylate (IBOA) has been identified as a major culprit sensitizer, but also other acrylates and (modified) colophonium have been reported as causes of ACD. OBJECTIVES: To report the two first cases diagnosed with ACD caused by the Dexcom G7 (DG7) glucose sensor. PATIENTS AND METHODS: Two children with suspected ACD from DG7 were patch tested with our medical device series with an addition of selected test preparations including two variants of modified colophonium - methyl hydrogenated rosinate (MHR) and glyceryl hydrogenated rosinate (GHR). Both patients were also tested with acetone extracts made from different parts of the DG7 sensor. The extracts were analysed by gas chromatography-mass spectrometry (GC-MS). RESULTS: Both patients tested positive to IBOA, hydroabietyl alcohol and GHR. In addition, patient 1 had a positive reaction to MHR and patient 2 had a positive reaction to colophonium. The GC-MS analyses showed the presence of IBOA and colophonium-related substances in the DG7 extracts. CONCLUSIONS: Both patients were diagnosed with contact allergy to well-known medical device-related sensitizers. The presence of IBOA and (modified) colophonium in a newly introduced (on the Swedish market in 2023) glucose sensor is remarkable and indicates an inadequate toxicological assessment of the materials used in the sensor.

Further Evidence of Allergic Contact Dermatitis Caused by 2,2'-Methylenebis(6- tert -Butyl-4-Methylphenol) Monoacrylate, a New Sensitizer in the Dexcom G6 Glucose Sensor.

BACKGROUND: Since the spring of 2020, we have seen several patients experiencing severe allergic contact dermatitis (ACD) from the Dexcom G6 glucose sensor after the composition of the sensor's adhesive patch had been changed. We have previously reported the finding of a new sensitizer, 2,2'-methylenebis(6- tert -butyl-4-methylphenol) monoacrylate, in the Dexcom G6 adhesive patch. Three patients with ACD from Dexcom G6 tested positive to this sensitizer. They were also allergic to isobornyl acrylate, a sensitizer present both in Dexcom G6 and in other medical devices previously used by these patients. OBJECTIVE: The aim of the study was to report the first 4 cases sensitized to 2,2'-methylenebis(6- tert -butyl-4-methylphenol) monoacrylate without a simultaneous allergy to isobornyl acrylate. METHODS: The cases were patch tested their own materials, a medical device series, and 2,2'-methylenebis(6- tert -butyl-4-methylphenol) monoacrylate in several concentrations. RESULTS: All 4 cases tested positive to 2,2'-methylenebis(6- tert -butyl-4-methylphenol) monoacrylate at either 1.0% or 1.5% in petrolatum, whereas 20 controls tested negative to both concentrations. CONCLUSIONS: The cases reported here provide further evidence of 2,2'-methylenebis(6- tert -butyl-4-methylphenol) monoacrylate as a relevant culprit sensitizer in patients with ACD from Dexcom G6. However, the initially used patch test concentration (0.3%) did not suffice to elicit positive reactions in these cases, which is why patch testing at 1.5% is recommended.

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.

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

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.