Freestyle Libre allergy

I just discovered this forum because the same thing happened to me. I’m also Canadian and developed T1D just under 2 years ago when I was 29. I was using the 14-day Freestyle Libre starting in April 2018 with no issues. By August they were occasionally coming loose early, seemingly due to the humidity/sweat, but I still wasn’t having any skin reactions.

In late 2018 - November or December-ish, I started having circles of red/irritated skin underneath when I took it off and sometimes they would come off early. The irritated skin was itchy but not “raw” per se. When this happened I would sometimes also be getting abnormally high readings from the sensor that didn’t match my finger-prick blood tests. (This happened with more than one sensor and I made sure to rotate arms.)

I took a few weeks off to let the irritation heal fully and then installed a new sensor last week. Within under 24 hours, I was seeing redness around the sensor and getting bad readings, so I took it off and it pulled two patches of skin off with it - definitely softer and more raw.

I didn’t think it was an allergy because I didn’t have any issues with it for the first 8 months, so it’s helpful to learn that it’s possible to develop them later. What are Tegaderm and Mastisol? Is there a link anyone can provide that sets out a list of possible solutions and how to use them?

Thanks so much.


@purplechrain, Welcome to FUD! Glad you joined, sorry you joined our club late. My son who was diagnosed at 12, still pines for the “easy” life of pre-diabetes. Really glad you are able to access CGM’s so easily. In addition to the Tegaderm and Masitisol which I will link below, you will find that are also barrier creams and Flonase which can be squirted on the skin prior to insertion which can deal with minor issues.

Finally, we have had many discussions on this site about this reasonably common problem, here is the wiki on it that @Michel made:

[EDIT] Corrected incorrect link (old one linked into the Lounge)

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Finally finally,

You may want to introduce yourself here. Our members don’t always catch on when you start posting in threads, and they like to welcome our new members.

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Welcome, @purplechrain. I am sorry to hear that you are having the same problem that my daughter is having. It seems very fishy to me that her problem started around the same time. I really think that Abbott changed something in their adhesive (I have heard other in the DOC complaining also). She has also been having problems with accuracy since the skin problems started. We just called last week to get a sensor replaced because it was so inaccurate. Unfortunately, the sensor that she is wearing now also seems to be inaccurate. About 4 years ago she tried a Dexcom sensor and was sensitive to the adhesive, but I am thinking that she should try it again.

@Purplechrain, sorry about the developing allergy you are seeing :frowning: Tegaderm is a type of solid adhesive tape, that you can buy on Amazon. Mastisol is a liquid adhesive that you can also buy there, similar to SkinTac. These liquid adhesives can serve as an isolating layer.

@Chris gave you some great info and links—check them and the wiki! You have many, many things to try there. The ultimate step, as you will read, but also the most inconvenient, is to introduce a thick colloidal layer under the patch. But you have many steps you can take that may resolve your issues!

Let us know how what steps work for you!

I bought some 3M Cavilon yesterday evening at my neighbourhood pharmacy and tried applying that before putting a new sensor on. The last two sensors caused the irritation/allergic reaction within 24 hours, so hopefully by tonight I’ll know whether or not the Cavilon works for me.

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