Does wearing the sensor >7 days increase scar tissue?

Hi Sarah,

I also use my sensors for 14 days, so I am hoping that I am ending my sensor sessions before anything irreversible starts to occur. However, if significant sub-Q scarring is occurring, I don’t feel (at least in my case) that it would be palpable.

History shows us that the first sign of scarring in many insulin pumpers was a loss infusion efficiency. If they knew they were scarring, they would have changed their site protocols before infusion efficiency dropped off.

Outside, usually a couple of inches posterior to the midline, about six to 10 inches below the hip.

The wire moving around can cause it to break. Applying tape around the sensor, as seen in the Dex manual, can help prevent excessive movement of the wire. The more the wire moves around, the less accurate the numbers will be. After your 8-10 days the wire may be in a bad position and causing the loss of accuracy. I always wear my sensor near the middle of my abdomen, but am sure my belt will not press against it. I get better accuracy during the second week, than the first.

Thanks for clarification; I agree 100%.

Let me also note, for those who might be blaming insulin alone, that infusion site IR occurs for another reason: Infusion sets are not just injecting insulin, they’re injecting at least one more powerful irritant- the carrier fluid, in which the insulin is dissolved. The strong, nasty “insulin smell” of drips from cartridge priming overflows, removal of bubbles, and etc. is a clear indication of how strongly your body reacts to this organic stuff.



(And depending on the freshness of “silicone rubber” seals present in the infusion pathway, a small amount of silicone is also being injecting as an unwanted pollutant.) I personally have a MUCH stronger reaction to the carrier fluid formula of one major brand, compared to the other two, and need to avoid that brand for exactly this reason.

I switch sides at least every two weeks. I have my pump on one side and the Dexcom on the other side of my stomach. I rotated the pump sites every time the pump cartridge is empty (200 Units in a Ping). I always move the Ping site as far as the inserter is wide.

Good luck! Work with your endo, CDE, and equipment reps. Then pick our brains.

I’ve had my Dex for about 2 1/2 months now and while I have tried to leave it in longer than 7 days and many people do, I start to itch from the adhesive but there is no scar tissue from the sensor at all. The support group I am in also gave the advice that after 14 days you will no longer have much accuracy but it can all depend on where you put the sensor but you should never have a problem with scar tissue so don’t worry about that, we all try and save money, maybe one day the insurance will pay more to keep us all healthier! Good luck

We just switched from Navigator. To restart the Navigator, we had to take the transmitter off, put it back on, and go through the motions. How does it work for Dexcom? I am sure it has been discussed here, but couldn’t find it.

You don’t have to do anything with the sensor or transmitter. You simply wait for it to say “replace sensor” and then choose “restart sensor” from the settings menu on the receiver. If you like you can first select “stop sensor” if you prefer for the 2 hour dead time to be more convenient for your schedule. I’m a new user as well and am currently on my 3rd sensor. I specifically changed the first sensor after 14 days. The second lasted 16 days before I got a “failed sensor” (sure enough I looked down and the tape had come mostly loose and the sensor wire itself was completely exposed).

Thanks. That is so convenient. With the Nav, you go through the routine, wait for 10 hrs, and then find it didn’t work. So, you start over. Then another 10 hrs . . . .

Regardless, the Navigator is a good product. We were quite happy with it except for the other stupid problems.

Rickst- It turns out that this flexifix really does bother my skin! Would this be the proper order of things if I used all these components for better adhesion and skin protection:
-clean area
-use IV prep. dry
-use skin prep. dry
-apply skin tac. dry
-insert sensor
This last time I waited a couple days to put the flexifix on the edges of the pad because it sticks perfectly fine the first couple days. If I did the same would I wipe Skin Prep on the skin around the sensor pad, dry (with hairdryer) and then put on Flexifit?
Thanks for your input. It’s hard to figure out the best order of all these things!

And, one more thing…the area where the sensor was actually looks bruised. Is that normal? And then there are just some reddish blotches I guess where the skin was irritated. You said you use udder cream to heal the area?

No I.V. prep- it’s little more than an alcohol wipe; those ingredients which are the same as Skin-Prep are best applied via the Skin Prep.



No Skin Tac, either: The liquid adhesive largely DISSOLVES the nearly-new Skin-Prep, creating an adnesive mixture in direct contact with your skin. This is probably where you went wrong.



In my experience, Skin-Prep must cover the entire area (under both Dexcom pad AND FlexiFix overlay, or else the adhesive on the FlexiFix will cause trouble. And finally - it’s probably a bad idea to add additional Skin-Prep “later”, because the Skin-Tac problem which I described above happens in the other direction, too: The Skin-Prep will partially DISSOLVE Dexcom adhesive around the Dexcom edges, and anywhere it’s been applied on top of the Dexcom fabric (it soaks in, creating a messy and ineffective mixture underneath.)



Great post. I’ve always done Dexcom and FlexiFix together, on top of just ONE application of Skin-Prep. I imagine that you’re getting gunky “melting together” problems with both the add-on Skin-Tac at the beginning, and with the subsequent add-on Skin-Prep to the Dexcom pad.

You shouldn’t add dissolving liquids to dry “layers” and dry pad adhesives which you’re already wearing.

I feel that a “bruised” Sensor insertion hole is a very bad indication. Perhaps you had an unlucky “bleeder”? The bleeding itself will provoke a huge increase in IR. And, with each microscopic “pull” or “push” on the wire, a call for more gets sent quickly- the coagulated blood, white cells, and other parts of the protecting-destroying-rebuilding response have been made hyper-sensitive.

Udder Cream is much cheaper than most “scar healing” salves, but it smells really bad. (From your photo, you might be at an age where smelling bad from a salve is, ahem, “very inappropriate”. You can certainly try one of those, too.) 2-4x per day, massaged more and more firmly as time goes by, seems to help my skin become more “normal” much more quickly. But don’t massage it too hard during the first few days, and stay away from the insertion hole (and any other skin-piercing cuts) until it’s fully sealed over.

Thanks for all the help! I did actually have a little bleeder with the first one, but the sensor didn’t fail so I stuck with it. That explains the bruising and probably the bump that is just now healing up after almost a week!

I might try your method of flexifix UNDER the dexcom pad next time. Let me make sure I’ve got this right…you do the cleaning routine and prep described on your page, cut the flexifix with the hole and then stick the sensor on top and insert? And the sensor stays well stuck to the flexifix?

If I could ask one more question…I’ve read a ton of posts and have tried a lot of things to keep the transmitter dry while showering and have been completely unsuccessful! Tried press n seal- no luck. tried waterproof tape on plastic covering-no luck. tried waterproof bandaids. I find that my skin feels most irritated once the sensor pad is wet. I actually dry it a few seconds intermittently after showering to try to dry it out quicker. Any better suggestions?

thanks again!