Those really sound like he's getting little cellulitises, which are usually some form of staph. I'd get him into the doctor, as you don't want them to get deeper into the tissue, if that is in fact what they are. Do they look a bit bruised at all? Our whole family have fought these infections, and have had to use oral antibiotics, along with topical treatments. Please look at the "Freaking Out...MRSA infection" post on here, and also, any older posts on MRSA. You may get some helpful information. We battled this quite a bit. And having a skin condition makes all of these children so much more prone to picking up these skin infections. I could be wrong, but the fact that they're pusing and that they're tender sounds very suspicious! Don't lose sleep over this tonight, but truly go get them cultured tomorrow if you can. In the meantime, bathe your little guy in a bleach bath (1/8 cup in a half bath) and try to put any antibiotic cream on them until you can get seen. Definitely draining these helps. Also, dial soap (the foaming kitchen hand soap) has triclosan in it, which helps fight the bacteria. This was recommended to us from UCSF dermatology clinic and the infectious disease dept. He may also need an antibiotic.
Good luck, and please keep us posted!