Is it possible for a baby to get diaper rash from taking antibiotics? My dd got a horrible rash, it almost looks like her skin is burned, she never had a diaper rash ever before, I noticed it started the day after she started taking antibiotics 3 days ago so that's why I think it's from antibiotics, we haven't changed her diet or wipes or diapers.S he does also have an upset stomach, ped warned me about that , but I am concerned about the rash.