Could this be?

Hi! There is something that happens with taking antibiotics and that is all of the bacteria inside of the lesions die, and so when you test the areas, there won't be a positive because they have already been killed off. That being said, HS doesn't really respond well to antibiotics as a general rule. Patients are on them long term to try to control HS, but it's not necessarily effective. There are a lot of things you/your doctor would want to rule out including shingles. (I am hoping they have already and that's why you have tried 3 different antibiotics.) What I would recommend if it's at all possible is searching for an HS-literate doctor. Not all dermatologists (or surgeons) are familiar. I usually search the words "hidradenitis suppurativa clinic" and then the city I want to look in to see what is available, because I'm finding that there are now clinics that are popping up specifically for HS. This is one time you want to
go for the best care possible, even if it's to rule out HS. 😀 ~Chelsea (Team Member)

Are you asking if it could be HS? I have bumps of all shapes and sizes. This does look like some of mine. Also it takes MONTHS for them to heal, some times they never heal. Also, for me the same bumps flare up a few times before actually healing. Do you have any blackheads in the area?