HELP PLEASE

Okay so my boyfriend got a blister on the shaft of his penis, he said he hard them before from jacking off too hard. Anyway we ignored it, it got worse, he had blisters all over the shaft, we stopped sex to see if that helped, it's been 2 weeks and the ones on his penis are better but it is moving up is stomach and he even has one on his wrist, we don't know what it is can someone help.