What can I do to treat itchy bumps in the torso area?

Any clue what this is & how to get rid of it? For a year+ I've had these bumps on my torso. I'm thin, no skin folds, never sweaty. Wear loose cotton clothing, rarely wear a bra. The bumps are on ribcage between breasts, & upper stomach. It often stings/itches. I've tried benzoyl perox, BHA, AHA, hydrocortizone, Desonide, tretinoin, Hibiclens, Cerave, Mupirocin, Xolegel, doxycycline, Keflex, Spiro, zinc soap, erythromycin, etc...nothing helps. Any ideas?