Allergic reaction

Charlotte got a sinus infection a week ago and the medication they gave her, she is allergic too.  I took her to the doctor and he told me to just give her anti histamines and it should go away in a week or two.  I woke up this morning at 3 to go check on her and her right eye was completely swollen shut, her lips were about 4 times their normal size, she had red welts all over forehead and she had a temperature of 102.  I rushed her to the ER thinking her airways could be closing off, but thankfully everything was okay.  The ER doctor proscribed her some stronger medicine and sent us on our way. Unfortunately she will have the swelling and red splotches for the next 2 weeks.  I told Kooper it looks like she went 3 rounds and lost them all!!