Hello,
I have only just come across this topic. I have posted elsewhere on the boards regarding the problem, and outlining exactly what it is. (Not in a medical way, but in a way of a person having it). If you are still having the problems, then I hope I can give you a bit of insight into my own treatment.
I had these large awfully painful lumps for 10 years before I was finally taken seriously about how much they had caused problems in my life. I must say mine were not under my arms but -- ahem --in a private part of my body

I was finally referred to a wonderful dermatologist who listened and looked. First time in 10 years that somebody had looked properly and taken me seriously.
He diagnosed this problem at once. Thank goodness, confirmation of the fact that something was definitely not right. I had up until then been given oral antibiotics because the general concensus was that it was "a bit of imflammation, or caused by tiny hairs". I was obsessed with thinking that I wan unclean, as you would be. I began to imagine that they thouight I was in fact imagining the pain these lumps caused me. All they could do was dismiss me. Urrgghh, it made me so mad.
Because I have lupus, amongst other things, they always try to put things down to that, inflammation in the body. It was absolutely nothing at all to do with lupus. So don't worry ladies. Anyway, I am going off the subject sorry. I live in the UK. I don't know where you live but if not here I don't think the names of the preparations will be the same. The treatment will be though. You must ask your doctor about it. I now use a antibacterial wash on the area. It is the same type that I washed in before and after my heart surgery, so I know it is highly recommended for its cleansing properties. After gently drying I then use a topical rollerball antibiotic preparation.
Of course with this treatment you have no pills to take and no problem of stomach issues. I took antibiotics for such a long time, they did nothing for the problem so in the end I just gave up taking them. I still get a bit of trouble with lumps, but they are so, so tiny now and nothing like the huge abcessy things I used to get.
Please tell your doctor about what I have suggested. You need to be free of this horrid thing. Best of luck.
goldenwings