Itchy Bumps, anyone?

I’ve been developing a field of itchy bumps where the sensor has been inserted. I rotate spots but it seems like the prior spots remain kind of inflamed for weeks afterwards. Any ideas on how to avoid this complication?

Is the problem where the sensor breaks the skin or is the problem with the entire area that is covered by the adhesive?

Since you describe a “field”, and not just a single spot, it’s almost certainly an allergy to the adhesive pad and/or skin preparation which you use. (And not the wire.)

So the key question is: How are you “preparing” the sites?
There’s several options available, but please tell me what doesn’t work for you now.

The problem is where the sensor breaks the skin.

The “field” is the various insertion points, one itch spot per insertion.

The sensor wire insertion point remains quite red and slightly inflamed for a couple of weeks in my case, but never really causes trouble. As I rotate spots about every two weeks (that’s how much I typically squeeze out of a single sensor) this is never a big issue.

But I do confirm that the spot remains sore and a little bumpy for a while, no need to worry unless it doesn’t heal at all.

Ciao, Luca

Sounds like an infection to me. I found Rick’s post on this subject very interesting.

I clean the site with alcohol, let it dry, and then spray Skin Prep.

Thanks Luca, that sounds like what I’m experiencing.

Alcohol irritates my skin. I stopped using alcohol.

Do you use an alternative to clean the site?

I just read the post, very interesting it is. This has happened to me even with sensors that only lasted a week. Perhaps there was movement going on that caused it, even in that short period of time.

I shower and use soap. I also shave the area. This might get rid of some dead skin cells too. My main focus was getting the sensor to stick for as long as possible. With this method my sensors typically don’t need any ‘help’ until day 10-12.

makes sense.

There’s 5 possible sources of your problem, but one thing’s for sure: You DO NOT! want to do it that way. One thing stands out from your description, and I’ll get to it after discussing everything to provide enough “background” information.

The 5 possibilities are: #1, infection; #2 alcohol-induced irritation; #3 Skin-Prep induced irritation; #4; Moving wire irritation; and #5; Adhesive irritation.

I'll address #1 and #2 together: Alcohol does a lot of it's "antiseptic" action by drying the cell walls and similar surface proteins of the "little buggers". As Helmut point out, it gets to be a very strong irritant for some people after chronic use. This includes me, as well as him. I used to nearly always get the "bumps" you describe when I was still using "I.V. Prep" helper wipes, which contain a lot more alcohol than the "Skin-Prep" wipes do.

It’s also been found, in well-designed research studies, to be a relatively poor antiseptic. A good soap scrub gets your target area cleaner than alcohol, biologically speaking, without subjecting your skin to alcohol’s extreme drying effects.

So if you need a real antiseptic after a soap scrub, rinse, and towel dry with a fresh-from-the-laundry hand towel, you need to move up to something “real”. (Nurses gently wiping alcohol at vaccination clinics, and not waiting for it to dry off, is mostly making Pts feel good- it’s not really doing much of anything.) There are lots of reasons why you might need an antiseptic – for example, you might be a MRSA carrier. If so, you have to live with it, and use something better:

Povidone Iodine instead. This is the “orange stuff” which they use in Emergency rooms, Operating rooms, and other clinics where large cuts will be made in the skin. It’s available in both wipes and big bottles. I prefer to use a big bottle, dripping onto a Q-tip, in order to keep it from getting all over my Application fingers :wink: It’s also much more economical to use this way. I have just one box of wipes, reserved for trips where I worry about the bottle spilling over or taking to much luggage space.

If you’ve had surgery and paid attention, you’ll remember that your MD leaves the PVI for at least 30 seconds per wipe, and wipes twice. Just like my complaint about the vaccination nurses-- you need to give it TIME to do it’s job. That’s what I advise for both #1 AND #2. Which brings us to

#3 and #5: Skin-Prep induced irritation, OR Skin-Prep fails to "protect": I frequently recommend Skin-Prep for Dexcom adhesive pads, and not just because it helps the glue: It also leaves a protective "barrier" film on your skin. For me, it reduces irritation. But I've never even heard of Skin-Prep in spray-on bottles, and don't even need to try it: I hate it already, and I know exactly why !!!

The proper application of Skin-Prep results in an even layer of film on your skin. No lumps, and no gaps! A spray bottle does the exact WRONG thing, splattering big droplets while leaving little empty spots. Those empty spots might get covered by big drops flowing downwards, into them, but probably not: Skin-Prep has considerable surface tension, so it likes to flow into spots which are already wet – but it HATES to flow from a wet area into still-dry skin. The Spray bottle leaves a splatter-gram, full of tiny blank spots.

So please try my oft-repeated instructions to double-wipe, using a Skin-Prep pad, assisted by a hairdryer. (I’m creating a page or two of “Rick’s tricks” on my page. It’s not done yet, but the “prepare your site” portion is in near-final draft. My page is at Just scroll past my “Recent Activity”, into my profile information, and you’ll see it. (I wish that Ning put a NAME= on that element, so that I could link straight to it…)

IF you still suspect Skin-Prep after using it properly, then you should other “adhesive-helper” products to see if you can find one which works and doesn’t irritate your skin. (Probably, one or another of the stick-on films or tapes: IV-3000, or Opsite Flexifix, etc.)

#4 is NOT your problem: If you were suffering ONLY from wire movement, then your IR would only be appearing at the shoot-in site. Your skin irritation appears over an area, instead of being local to the exact point where the wire went in. - - - - - #3 and #5: Now that you've got all the "Required" background....
here's your problem:

The irritation occurs underneath the Transmitter case assembly and the Transmitter itself, and NOT the entire Sensor pad. It’s happening because the Transmitter assembly is sealed. Any solvent remnants from Alcohol and Esters in Skin-Prep, along with your own sweat, have no chance to evaporate. You need to let all of these nasty liquids dry completely before inserting the Sensor, but you also need a better barrier-- one which will keep your sweat from reaching the surface, building up, and causing irritation.

Maybe Skin-Prep, applied better, will do this. If not, then you’ll need to switch to an actual pad underneath, with just a tiny hole for the Sensor wire to be shot through. The area of non-breathing plastic is over 10x as large as the little hole which you actually need for the wire. With a more complete barrier, you can keep sweat from getting to the surface of your skin and causing all that irritation – it just gets re-absorbed back into the lower layers of your skin, rather than building up on the surface.

It’s only a guess, of course. But this is my best guess. Good luck, and let us know whether you ultimately solve it – and what you tried differently!

Thanks Rick, that’s alot to digest!

I’ll start by cutting out the alcohol. I have povidon iodine and will use that as suggested. I have a nearly full spray bottle of Skin Prep. Would it work to saturate a pad with it, wipe it on evenly, and dry it?

Yes, but wipe TWICE and let it dry each time (all the way to seeing tiny cracks, a sort of “sheen”, in the film. This involves a very gentle wipe, and needs a smooth, tight weave. Gauze has holes which are to big, and fabric which is too stringy. I don’t know where to buy wipes which aren’t already loaded up with something else. (Something you don’t want.) So buy 'em off the Internet, instead.

You also NEED that hair dryer technique to keep theapplied liquid from flowing downwards, under gravity, towards the bottom of the wiped area. (Full instructions on my page.) If you allow it to flow downwards, which happens almost instantly, it flows down and away from under the waterproof/vapor-proof Transmitter assembly… as well as the top of the pad fabric. You’ll still have sweat and sweat vapor getting onto the pad surface and Sensor contact area in the middle.

The outside of the pad has holes, allowing for adequate evaporation. But sweat can’t evaporate through the pad holes under the Sensor assembly, or from inside the uncovered Sensor area (there’s simply no way out). Humidity and sweat begin to build up, irritate, itch, and cause IR.

Update on this. I had a very comfortable two weeks with my last sensor. Here’s how I changed my usual method:

I did not use alcohol to prep. I used a skin cleanser that had a small amount of abrasiveness to it, to make sure the area was very clean. I applied the Skin Prep by spraying it onto one of those thin cotton squares and applying it to the area, using an upward motion. I did this twice, letting it dry thoroughly between applications.

I can still see a little red dot where the sensor had been, but it is not itchy or uncomfortable like it was in the past. I consider this a success, thanks!

Sounds like perfect results! To help clear up the tiny dot where the actual hole was, I use “udder cream” starting about 24 hours after I’ve changed sites. Massage it in well, morning and night.

Mooo! Thanks.