cut and bump

Question
So, my male rat Baley is under 1 year old, and about a week
ago I had put plastic mesh (the stuff used for arts &
crafts...I can't remember what it's called) on to the wire
platforms in his cage. I noticed my other rat (a new
addition...just got him a few weeks ago) get his toe caught
in this mesh. Then a few days later I noticed Baley had
what looked like a blood blister on his index finger of his
left hand, and the finger was a little swollen. Well, the
blood blister got a little bigger and the swelling hasn't
really gone down, but the blister turned a brownish color
like coagulated blood, so I figured it was healing. I also
put some neosporin on it the past three days. Tonight, the
finger was looking good, but when I just put him in his
cage and came back there was a small trickle of dried blood
coming from it. I think the blood blister may have just
reached the skin, so I was okay with that. But then I
noticed he's got a somewhat large (a little smaller than
his hand) bump on the wrist of that hand. I had not seen it
before today. It has hair on it and he's using the hand as
normal. He hasn't been acting strange or anything, but I
was just wondering if this might lead to something serious
if I don't bring him to a vet?
Thanks

Answer
Are you using the needlpoint canvas?  I use that and never had a problem with it but its interesting to know you have. I wonder if there are some that come with holes bigger than others because I cant see how my rats would get their nails caught in the holes.  Thanks for bringing that up this is important to know.

I would rub then new bump with neosporin also for a few days and see if it isnt a tiny abscess.   See if it gets a head on it!