Caleb's ear did this a couple of weeks ago. Only we didn't know it was a bug bite. When dh got him up from a nap, his ear was huge, red, swollen and sticking out from the side of his head. We took him over to the doctor asap, and he said that it was a bug bite and to give him some of his allergy medicine. (He only takes it in the winter, if he has a cold). Benadryll would work too. The ped said the reason it swells up so much is because there is very little tissue for the bug bite's venom to go deeply into and so it just swells instead. I hope it goes down soon and your ds feels better!