There was a dramatic shift in this before and after the heart attack. I mean, overnight. After the heart attack and the stent placement, the Plavix ($220/month, but who's counting) caused me to bruise easily. The skin brittleness started almost right away as well. At that point, there was the Plavix, the beta blocker, the ACE inhibitor, and the acetylsalicylic acid**.
The Plavix is gone now (thank you!), the beta-blocker is gone, but the statin, ACE inhibitor, and aspirin remain. Doc says the sudden shift in skin condition is most likely the aspirin. My dad was on aspirin in his 60s, too, and he had the same issue.
It could be that my skin - specifically, arm skin - decided to get brittle nearly overnight, coincident with the heart attack, but that's a bit too much of a coincidence for my tastes. It could also be that the two shocks I got to get me through atrial fibrillation caused it. I'd accept that as a suspect. The Fentanyl and Verced they used to "reduce pain" (I wasn't really in pain) and wipe the memory of the shocks may have had an effect, but those were one-shot usages. And it could well be a cumulative effect of age, like you say, in combination with one or more of the drugs I'm taking now.
We're complicated, aren't we?
**Guy walks up to the pharmacy counter and says, "Can I get a bottle of acetylsalicylic acid?" The bemused clerk says, "Do you mean aspirin?" The guys smacks his forehead and says, "Oh, yeah! I never can remember that name."