Cutaneous adverse events related to FreeStyle Libre device – Authors' reply

We thank Nesrine Brahimi and colleagues for their letter regarding skin adverse events in the IMPACT trial.1Bolinder J Antuna R Geelhoed-Duijvestijn P Kröger J Weitgasser R Novel glucose-sensing technology and hypoglycaemia in type 1 diabetes: a multicentre, non-masked, randomised controlled trial.Lancet. 2016; 388: 2254-2263Summary Full Text Full Text PDF PubMed Scopus (581) Google Scholar Although published data are scarce, the number and type of events reported for FreeStyle Libre in the IMPACT trial were similar to those for other systems in which a device is worn on the skin for a period of time using a medical-grade adhesive.2Ramchandani N Arya S Ten S Bhandari S Real-life utilization of real-time continuous glucose monitoring: the complete picture.J Diabetes Sci Technol. 2011; 5: 860-870Crossref PubMed Scopus (64) Google Scholar, 3Wong JC Foster NC Maahs DM et al.for the T1D Exchange Clinic NetworkReal-time continuous glucose monitoring among participants in the T1D exchange registry.Diabetes Care. 2014; 37: 2702-2709Crossref PubMed Scopus (246) Google Scholar Skin symptoms can occur with high skin temperature and humidity, along with long duration of exposure, all of which might be contributing factors to adverse events.4Englert K Ruedy K Coffey J Caswell K Steffen A Levandoski L for the Diabetes Research in Children (DirecNet) Study GroupSkin and adhesive issues with continuous glucose monitors: a sticky situation.J Diabetes Sci Technol. 2014; 8: 745-751Crossref PubMed Scopus (50) Google Scholar, 5Heinemann L Kamann S Adhesives used for diabetes medical devices: a neglected risk with serious consequences?.J Diabetes Sci Technol. 2016; 10: 1211-1215Crossref PubMed Scopus (58) Google Scholar Sensor-wear-related symptoms were recorded as adverse events in the IMPACT trial if the effects were severe and lasted for more than 7 days, or if the patient required prescription medication for the event to resolve. Adverse event severities were recorded on the basis of a health-care professionals assessment of mild, moderate, or severe events. According to the study protocol, individuals with known sensitivity to medical-grade adhesives were excluded from participation. However, we reasonably expected that a few participants might have been unaware of their sensitivity until they had exposure to the product for longer than a few days. For participants with adverse events involving skin symptoms during this trial, symptoms (including severe) were resolved by use of barrier products (eg, Cavilon spray) or drug therapy (eg, zinc ointment, Fenistil gel, or hydrocortisone cream) as prescribed, or simply by relocating the device to another area of the skin such that the effects were maintained at a tolerable, background level. In other cases, although the adverse events were generally mild or moderate, the longevity of the symptoms, despite use of treatment, contributed to the participant's decision to withdraw from the trial. None of the participants withdrew because of health-care professional advice to stop wearing the sensor. Since completion of the IMPACT trial, minor design changes have been made to FreeStyle Libre. These changes are expected to improve breathability of the skin that is in contact with the sensor and to facilitate the exclusion of moisture between the sensor–skin interface. We conclude that although some individuals might be intolerant to using devices with medical-grade adhesive, others might have manageable skin symptoms from sensor wear. Overall, we believe that the benefits of using such a system generally outweigh the risks. Ultimately, the decision to continue or discontinue the use of a medical device when localised skin symptoms occur has to be made in consultation with the patient. JB reports personal fees from Abbott Diabetes Care, AstraZeneca, Insulet Corporation, Integrity Applications, Lilly, NovoNordisk, and Sanofi. RA and PG-D declare no competing interests. JK is on the advisory board for Abbott Diabetes Care, and reports personal fees from Abbott Diabetes Care, Lilly, Novo Nordisk, Berlin Chemie, Medtronic, Sanofi, MSD, and AstraZeneca. RW reports personal fees from Abbott. Novel glucose-sensing technology and hypoglycaemia in type 1 diabetes: a multicentre, non-masked, randomised controlled trialNovel flash glucose testing reduced the time adults with well controlled type 1 diabetes spent in hypoglycaemia. Future studies are needed to assess the effectiveness of this technology in patients with less well controlled diabetes and in younger age groups. Full-Text PDF Cutaneous adverse events related to FreeStyle Libre deviceRecently in The Lancet, Jan Bolinder and colleagues (Nov 5, 2016, p 2254)1 conducted a multicentre, non-masked, randomised controlled trial to test the value of an innovating sensor-based flash glucose monitoring system (FreeStyle Libre; Abbott Diabetes Care, Witney, Oxon, UK) on the reduction of exposure to hypoglycaemia in adults with well controlled type 1 diabetes. They observed a 38% reduction in time spent in hypoglycaemia by participants using FreeStyle Libre, compared with those using a self-monitored glucose testing method. Full-Text PDF FreeStyle Libre: contact irritation versus contact allergyNesrine Brahimi and colleagues (April 8, p 1396)1 recently expressed their concern on the origin and management of cutaneous adverse events arising from FreeStyle Libre (Abbott Diabetes Care, Witney, Oxfordshire, UK), a sensor-based flash-continuous glucose monitoring system. A study by Bolinder and colleagues (Nov 5, 2016, p 2254)2 indeed reported adverse skin effects when participants were using the device, although participants with a known sensitivity to medical adhesives had been excluded from the trial. Full-Text PDF