Contact Allergens Lurk in Diabetes Devices

Heidi Splete

May 01, 2023

Diabetes devices represent a major advancement in the management of diabetes, but they can cause skin reactions that affect patient adherence and quality of life, Jennifer K. Chen, MD, said in a presentation at the annual meeting of the American Contact Dermatitis Society (ACDS).

Dr Jennifer Chen

Advanced technologies used for the management of diabetes fall into three main categories, said Chen, of the Department of Dermatology, Stanford University, Redwood City, California. Continuous glucose monitoring (CGM) devices, which are worn on the body, collect glucose measurements. Continuous subcutaneous insulin infusion (CSII) devices are attached to the body via an infusion set and are now available as tubing-free patch pumps that are attached directly to the skin via a catheter. Glucose-responsive insulin delivery systems combine the sensing and delivery features of the other two types of devices.

Once thought to be rare, reports of skin complications related to diabetes devices have been increasing in recent years, she said. Some reports suggest that at any given time, skin complications may affect as many as one quarter to one half of patients who use these devices, "so this is an important issue," she emphasized.

"Skin reactions are a major factor in device discontinuation, so we as clinicians need to be really proactive about treating these reactions," said Chen.

Risk factors for skin complications related to diabetes devices include sensitization to the adhesive used with the devices, as well prolonged exposure to the device, Chen said.

Younger age also appears to be a risk factor, as is a compromised skin barrier in the area where the device is used.

Unfortunately, obtaining details on the specific adhesives and the raw materials used in these devices, so as to customize patch testing, remains a challenge, Chen said. "Patch testing initially was often negative to commercially available allergens, even while patients were testing positive to pieces of device adhesive," she noted.

Consider Isobornyl Acrylate

An article published in 2017 in Contact Dermatitis was "a major breakthrough" in that it identified isobornyl acrylate (IBOA) as an allergen in connection with the Freestyle Libre, a CGM device that was relatively new at the time. The finding was serendipitous, Chen said. A patient being treated for suspected allergic contact dermatitis in connection with use of a Freestyle Libre device was tested for IBOA accidentally, she explained. The nurse administering the patch test thought that this was part of the standard acrylate series.

Subsequently, researchers identified 15 patients who had experienced reactions to the Freestyle Libre; 12 of 13 patients who were patch tested for IBOA tested positive. IBOA was found throughout the device, particularly where the top and bottom plastic components were connected, said Chen. This suggested that the IBOA was in the device housing and had diffused into the adhesive that attached the device to the skin.

An article published in 2018 in the Journal of Diabetes Science described three patients who developed severe allergic contact dermatitis from IBOA while using a CGM device, Chen said. The investigators confirmed that there were no reactions to the adhesive itself, again suggesting that IBOA had diffused into the adhesive from other parts of the device.

Although the authors were bound by a confidentiality agreement regarding the individual adhesive components, "the authors noted most of the acrylates in the adhesive were not present in commercially available acrylate series for patch testing," she said.

IBOA, the ACDS' Allergen of the Year in 2020, is common in sealants, glues, and adhesives, Chen said. Although IBOA had been reported infrequently as an allergen, it has now been identified as a "potential culprit" behind skin reactions in many diabetes devices, including CSII and CGM devices, she said.

In addition, N,N-dimethylacrylamide (DMAA) is an allergen that has been identified in several diabetes devices and often occurs with IBOA in medical-grade UV-cured adhesives, Chen noted. Other allergens identified in diabetes devices include colophony, which is present in many adhesives, as well as other acrylates and epoxy resin.

Diabetes devices are constantly evolving. IBOA is no longer found in Freestyle Libre devices. It is important that clinicians stay up to date with the medical literature and advocate for partnership with device manufacturers, Chen emphasized.

Patch Testing

When diabetes devices are suspected as the source of allergic contact dermatitis, a minimum of a baseline series that contains colophony at a concentration of 20% in petrolatum should be carried out, Chen said. Commercialized patch test trays, which include plastics, glues, acrylates, epoxy resins/isocyanates, and colophony derivatives, should be ideal. "Personal-care products should be included if they are potentially relevant," Chen added.

Chen shared tables published in Contact Dermatitis in 2021 with examples of screening test series. She said to consider including screening for other allergens more recently discovered in diabetes devices, including 2,2'-methylenebis(6-tert-butyl-4-methylphenol) monoacrylate (MBPA) 1.5% pet; dipropylene glycol diacrylate (DPGDA) 0.1% pet; and butylated hydroxytoluene (BHT) 2% pet.

Testing for monomethyl ether of hydroquinone should also be considered; this may be included in the test preparations for IBOA and DMAA.

Management Strategies

For patients who experience skin reactions to their diabetes devices, consideration may given to relocating the device to another area of skin or changing sensors more frequently, Chen said.

For some patients, the reaction can be managed with corticosteroid cream, ointment, solution, or nasal spray. Topical antibiotics or topical antihistamines can be helpful, as can barrier dressings, solutions, or sprays, she said. The best solution is to change to a device that does not have the culprit allergen, "but that is difficult, since we don't know what is in these devices," she said. Good alternatives include the Eversense CGM device or devices that have been demonstrated not to contain IBOA, such as the Freestyle Libre 2 or the newer version of the Omnipod, an insulin delivery system

Looking ahead, Chen said that "mandatory labeling is needed, as devices with the same name may have different compositions, depending on the date of manufacture." Allergens relevant to people with diabetes are constantly evolving, and many are still unidentified, so clinicians and manufacturers need to work together to identify the culprit allergens and their sources, she said.

Chen has served as principal investigator or subinvestigator for Amgen, AbbVie, and Sanofi-Regeneron and as a consultant for Purity Brands, LLC.

American Contact Dermatitis Society (ACDS).

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