I did not realize how important friction - the consequence of objects rubbing against my skin - was until last autumn. Already earlier, I successfully identified a type of eczema as caused by mechanical properties of the prosthetic arm (then, congestion eczema resulted from ill fitting Ossur liners). So maybe the mechanics of prosthetic suspension remains a main source of contemplation for the near future.

Mostly, I would get occasional rashes under the liner, and that was then attributed to poor hygiene, sweat, allergy against the material of the liner, some obscure skin disease maybe or whatnot. A dermatologist prescribed me various types of steroid or non-steroid type anti-eczema creme, and after a while the rash would subside. With treating a rash, one will also keep the stump still, or be generally more subdued, one will by and large avoid dumb maneuvers with the prosthetic arm on, such as moving a room of furniture or so, and delay all these activities to a later point in time when the stump has recovered. So maybe after all, the cremes never were that much help as just staying out of trouble.

Now, I can clearly document the appearance of a friction rash on my stump, after moving out stuff from my cellar without wearing the prosthetic arm at all.

Not only are there abrasions surrounded by ill defined red minimally swollen areas. These would be the result of direct mechanical strain. Also, the arm exhibits polka dot patterns of folliculitis-like redness that one would not necessarily associate with friction (unless I told you that all that impacted this arm was pure friction for three days, when I moved out stuff from my cellar; no problematic surfaces, so allergy very improbable, no detergents at this point in time, so no chemical or toxic reactions to be expected, just good old furniture with relatively clean surfaces).

Around the same time, I got serious rashes and itchy blisters from wearing my passive prosthetic arm for ballroom dancing (Rock'n'roll, Tango, etc.). There, I would bend and extend my elbow unusually often compared to other times, like, when sleeping ; ) So it was clear that mechanical strain was far more an issue than microbial invasion of my cellar and ballrooms in general.

So the appearance of this *is* caused by friction against my arm stump. If you'd have to examine this as general practitioner and tell the patient what it was, I bet that >90% of the doctors will have no idea and with that, they also cannot effectively treat it. And that, in its essence, is another brick in my argumentative wall that then will read "arm amputation is a rare condition, so rare that people and doctors do NOT know shit from shinola".

Interestingly, the rash that I get from "just wearing the prosthetic arm" also looks like that.

Treatment is achieved by wearing a tube gauze over the area of the arm that is most exposed to friction. For my prosthetic arm, that is the area below the elbow. Then I pull the liner over it. Not the rest.

And with that, I also get a lot less rashes (or none at all) on the distal end of the stump. Funny, isn't it.

The issue of skin rashes, burns and issues related to use, build and design of both myoelectric and body-powered prosthetic arms is discussed in this article in depth:

Publication [link]