Manufacturing Process Changes and Reduced Skin Irritations of an Adhesive Patch Used for Continuous Glucose Monitoring Devices

Perceptions of Continuous Glucose Monitoring Systems in the T1D Exchange Diabetes Registry: Satisfaction, Concerns, and Areas for Future Improvement

Manufacturers continue to improve performance and usability of continuous glucose monitoring (CGM) systems. As CGM becomes a standard of care, especially for people on insulin therapy, it is important to routinely gauge how satisfied people with diabetes are with this technology. This article describes survey feedback from a large cohort of people with diabetes using older and current CGM systems and highlights areas of current satisfaction, concern, and future system improvement.

Contact allergy to the Dexcom G6 glucose monitoring system -role of 2,2'-methylenebis(6-tert-butyl-4-methylphenol) monoacrylate in the new adhesive

BACKGROUND

Skin reactions to the glucose monitoring systems Dexcom G5 and G6 have been rare. In 2019, the components of the adhesive were exchanged for better skin fixation. Since then, more and more patients experienced severe skin reactions. A few months ago, 2,2'-methylenebis(6-tert-butyl-4-methylphenol) monoacrylate (MBPA) was identified as a new component in the adhesive of the G6 model. Furthermore, it was suspected that isobornylacrylate (IBOA) was also a component of the exchanged adhesive.

OBJECTIVES

Our objective was to investigate if MBPA plays a major role in the increasing skin problems of patients without a history of IBOA-sensitization. Furthermore, our aim was to examine whether IBOA is contained in the newer model adhesive and may also contribute to allergic contact dermatitis (ACD).

PATIENTS AND METHODS

Five patients with a newly occurred ACD caused by the glucose monitoring system Dexcom G6 were investigated. Patch testing including MBPA in 3 different concentrations, as well as IBOA were performed. Gas chromatography-mass spectrometry of the newer system Dexcom G6 was carried out.

RESULTS

All patients were shown to be sensitized to MBPA, while MBPA 0,5% showed the strongest reaction. On the other hand, IBOA was tested negative.

CONCLUSION

In our study group MBPA was observed to be the triggering allergen of the recently changed adhesive.

Modern diabetes devices for continuous blood sugar measuring: Limitations due to contact allergies

During the past years, diabetes diseases have increased significantly worldwide. However, new technologies such as continuous glucose measurement using a subcutaneous sensor are developing just as rapidly. A continuous improvement in insulin pump therapy is also contributing to an improved quality of life. A common feature of these modern devices for diabetes therapy is that they remain fixed in place on the skin for several days. In recent years, skin reactions, in particular pronounced contact dermatitis due to the devices and their adhesives have been increasingly reported. In particular, isobornyl acrylate, which used to be included in a glucose measurement sensor set, was identified as a main allergen. Development of contact allergy can result both in a necessity to quit the measuring system and in allergic cross-reactions to other systems.

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.

Cutaneous Complications With Continuous or Flash Glucose Monitoring Use: Systematic Review of Trials and Observational Studies

BACKGROUND

Continuous glucose monitoring (CGM)/flash glucose monitoring (FGM) use in diabetes management is increasing. Cutaneous complications associated with these devices were reported. We conducted a systematic review to provide an overview of cutaneous complications with CGM/FGM use.

METHODS

We identified observational studies and intervention trials that report on cutaneous complications with CGM/FGM use up to January 14, 2019. Studies were identified through Medline, Embase, and PubMed, or with hand searching of the previous publications. Screening was duplicated and data extracted to consider four main themes: incidence rate and severity, participant perspectives of cutaneous complications, potential solutions, and future directions in diabetic technology relevant to reducing cutaneous complications.

RESULTS

A total of 54 eligible studies were identified. The overall event rate of cutaneous complications reported from 19 trials was one event per eight weeks of sensor wear-time of which 1.5% were considered severe. The most common cutaneous complications were wear-related erythema, itching, and induration. Although skin irritations were the most common cause of CGM/FGM discontinuation, most users experienced less pain or discomfort with CGM/FGM than capillary blood glucose testing. Future technological advances may reduce, but not eliminate cutaneous complications.

CONCLUSION

The incidence rate of reported cutaneous complications with CGM/FGM use from the available literature is low, with one event per eight weeks of sensor wear-time. Reported complication severity was also low, leading to low rates of CGM/FGM discontinuation. However, there appear to be discrepancies between reporting in trial and observational data. Greater constancy in reporting is necessary to understand the frequency of this issue.

[Contact allergy due to insulin pumps and glucose sensor systems]

The design and development of insulin pumps and various glucose sensor systems has an enormous impact on life quality of diabetic patients. Surveillance and therapy of diabetes has improved due to the new diabetic devices, which are affixed to the patients' skin for several days. Since their introduction, irritant and allergic contact dermatitis have been frequently reported. Patients often acquire contact sensitization to isobornyl acrylate, N,N-dimethylacrylamide or formerly to 2‑ethyl-cyanoacrylate. These contact allergens were found in the patch, in the glue to affix the box on the patch or in the casing of the system itself. Development of contact allergy to substances of these systems may result in the need to abandon modern diabetic devices.

Evaluation of Isobornyl Acrylate Content in Medical Devices for Diabetes Treatment

Background: Along with increased usage of continuous glucose monitors, flash glucose monitors, and patch pumps by patients with diabetes, the frequency of skin reactions has also increased. Skin irritation and itching can be annoying to users. However, more serious contact allergies to one or more components of the adhesives or plastic material of the housing of the devices can become lifelong. Redness and itchiness are so strong that patients can no longer use a particular system. In August 2017, a major culprit allergen, isobornyl acrylate (IBOA), was identified for these more serious reactions. Objectives: Our objective was to evaluate IBOA content in different medical products. Methods: The plastic material used for the housing of the Freestyle Libre (n = 3), Dexcom G6 (n = 3), and Enlite (n = 4) was analyzed for IBOA content by gas chromatography-mass spectrometry. Adhesives of the different systems were also analyzed. Results: IBOA was found in the housings of Freestyle Libre and Enlite sensor, but not in the Dexcom G6. Conclusions: Patients with an IBOA allergy should consider switching to a medical product without IBOA. Furthermore, removal of IBOA from devices that contact the skin is encouraged.

Documentation of Skin-Related Issues Associated with Continuous Glucose Monitoring Use in the Scientific Literature

Background: The average wear time of continuous glucose monitoring (CGM) systems steadily increased over the last years. Increased wear times are likely achieved by using adhesives with a longer adherence time, which may have a more pronounced effect on the skin than adhesives with shorter adherence time. Methods: In this project, a structured literature search was performed to assess how potential skin-related issues with CGM usage have been reported in scientific literature in the last 5 years. The literature search was performed with four search terms in the PubMed database. Results: In sum, 279 articles were analyzed. Skin-related issues were mentioned in 19.0% of articles (53 out of 279). With respect to articles mentioning skin-related issues, CGM performance or efficacy was the study's main topic of most of these studies, whereas the minority used CGM as "add-on" to assess other objectives. There was a varying degree in how detailed skin-related issues were described and no uniform structured documentation was given. While some articles only described findings, other articles already documented final diagnoses, such as contact dermatitis. Furthermore, inconsistent wordings for comparable issues were used. The most frequent issues were pain, itching, erythema, bleeding, bruising, and allergic reactions. Conclusion: To draw possible conclusions about the occurrence of skin-related issues during CGM use, more reports about skin-related issues in scientific literature are needed. A more detailed and uniformly structured documentation, possibly facilitated by a generally accepted guideline for structured descriptions, of skin-related issues could be helpful to enable clear differentiations between the described skin reactions.

Toward Long-Term Implantable Glucose Biosensors for Clinical Use

Continuous glucose monitoring (CGM) sensors have led a paradigm shift to painless, continuous, zero-finger pricking measurement in blood glucose monitoring. Recent electrochemical CGM sensors have reached two-week lifespans and no calibration with clinically acceptable accuracy. The system with the recent CGM sensors is identified as an “integrated glucose monitoring system,” which can replace finger-pricking glucose-testing for diabetes treatment decisions. Although such innovation has brought CGM technology closer to realizing the artificial pancreas, discomfort and infection problems have arisen from short lifespans and open wounds. A fully implantable sensor with a longer-term lifespan (90 days) is considered as an alternative CGM sensor with high comfort and low running cost. However, it still has barriers, including surgery for applying and replacing and frequent calibration. If technical refinement is conducted (e.g., stability and reproducibility of sensor fabrication), fully implantable, long-term CGM sensors can open the new era of continuous glucose monitoring.