I keep getting these bug bite like bumps on my body. There are not a lot of them but the 2 that I have had on my upper arms have turned into almost red welt looking things when I itch them. I can't figure out where they are coming from. I treated my whole house and car for bed bugs because I was terrified that we had those but the exterminators that came to look at my matresses and stuff said they found nothing. They take a long time to go away too. It only stays welt like for a couple days then it shrinks but some of them itch bad and some of them don't. Does anyone have any idea what this could be?