Suggest Treatment For Itchy Bumps Under Armpit And Breast

I have itchy bumps under my armpit an one on my arm and some under my boob and under my leg and I was around a kerosene heater for a few weeks staying at my boyfriends sisters house these bumps didn t occur until a few days after I left I haven t been around the kerosene heaters since I left and it s been a week and a half the bumps are still on me is this okay? And how can I make them go away my boyfriend has bumps on his genital area to ?