I'm rather lost in the first couple of posts that I read, so I'm just going to give my advise. Sorry if it has already been given.

Why were you holding a hermit crab in the first place? These types of pets are for looking at, not touching. They're about the same as a frog. The salt (which is nothing like sea salt) absorbs into the skin of the crab and will shorten the life span.

To have a hermit crab let go of you, put it in water. The crab will eventually let go. Get him out of there immediately, or he'll drown, but that was the best way I found out how to get crabs off me.

Please don't use any other type of utensil. You're going to hurt him.

As far as the disease discussion. Any animal can trasmit a disease. Salmonella is always a huge thing to be careful of when handling reptiles or amphibians. It also depends on how clean you keep the cage. If the animal has a dirty cage, infection of your wound is more likely. If the cage is relatively clean, infection is still likely, but not as high of risk.

Clean your wound with a good antibiotic. Keep it covered. Don't hold hermit crabs all day and don't allow anyone to pry the animal off your skin. We found out what that did, hurt you more than it hurt the animal.

Good luck