Facial Swelling

Hi there everybody! I am a first semester nursing student, and just recently found this site. It has really helped with my care plans. But today I have a question concerning facial swelling. Yesterday, my husband had a red bump on the left side of his nose. Today, the upper left side of his face is swollen and his eye is puffy. I looked up possible causes of facial swelling as well as diagnosis flow charts, but I'm still not sure what is causing it. He has not had an injury or insect bite that he is aware of. He has had a recent change in his medication (from Glyburide to Glipizide and from Prograf to Rapamune) but his nurse said none of his medications should produce those side effects. He has to wait to hear back from his doctor. Do you have any suggestions on how we should treat it or what may be causing the swelling?