What Causes Red Itchy Bumps In The Groin,arm Pits And Waist?

This may sound like acne but not sure anymore. Starts out small red bump that itches with in 6-12 hrs its a pustule that pops with brown yellow puss that’s sticky not like acne that’s more liquid. Some start out small others one min its fine next they range from dime size to golf ball. I had about 100+ of these in groan under arms arm pits waist but no where else