Karrie, due to silkbacks extreme genetic skin mutation, they are much more susceptible for damage from UV and from heat. They need lower levels of UV than regular dragons.
It looks like you have a dual dome fixture. So I assume you have the basking (heat) bulb in one, and a UVB producing bulb (coil/compact/etc..) in the other. Correct?
Eitherway, I don't think the UV situation has anything to do with your issue at hand. No pun intended. You need to lower your temps for sure. I don't think that caused the issue either, but it could have contributed.
Silkies are also much more susceptible to dehydration, and when the skin and body are dehydrated, it cracks and breaks even easier. Have you tried the honey I've mentioned? How are things going?
I don't really see anything too rough in your tank. So it could just be from shedding complications. I would definitely do some research into Silkie care and figure out what other silkie owners are using on the skin. I haven't been around anyone with a silkie in a long time, they really fell out of favor due to all of their health issues.
But for now, I would definitely be using the raw unpasturized honey on the hand to help it heal and prevent infection.
I agree that basking temp. is way too hot. Mine basked at around 90 F. I also aree that hone would be good on that area, pretty much the best thing you could use. I did not bathe my silkie very often, bathing actually dries their skin out more. I applied 100 % natural allow with NO additives to him about once a week or so, more on areas that were having a hard time shedding.