What skin infection is this?

Hello! My kitten whose 11 weeks starting having bumps all over his skin. Took him to the vet and the vet said it’s a skin infection but not clear what it is. He was given antihistamine and antibiotics (is currently on second day of 5 days antibiotics) Today some of the bumps popped and you can see red skin exposed. I’ve attached pictures of some of the bumps (popped and unpopped) I’m curious what exactly it is if anyone knows. Thanks 

Hello!  I am not about to try to diagnose your kitten over the internet but think your vet might be interested to see the 'after' pictures in case they feel that more sampling, pain relief etc is indicated.

Would strongly advise contacting them again and asking to be triaged so that they can get you seen on the timescale they feel is appropriate.