I don’t have this particular issue, but I’ve read that stretchy, velvety skin is common in EDS. I did develop stretch marks but it was during rapid weight gain so I expected it. Sorry I’m not more help, maybe someone else here is experiencing this issue. You said you had some saliva cortisol testing done, what all hormones were checked? And make sure you get copies of the reports. Experience has shown me that they often call to say ‘your labs are normal’, when in fact they aren’t. Also, have you been diagnosed with EDS, or anything? Or still trying to fit the pieces together?
I do, however, have other skin issues. Over the last 2 years, I’ve noticed my skin aging rather quickly… more wrinkles and almost a ‘shine’ to my skin that I never had. I’m only 28, fyi. I’ve read that a hormone imbalance, particulary DHEA, can cause accelerated aging. I am low in DHEA, but became worse (fatigue & faaaast weight gain) after starting it so my doctor stopped it. I also have poor wound healing (but not the wide scarring typical with EDS).