What Causes Swollen Lips And Cheek?

my daughter woke up this morning with a swollen lip and cheek. she is unusually lethargic. she has eaten several popcycles to cool her off and isnot complaining about tooth pain. she is non verbal autistic and cant comunicate hee problems to help us out just chronic whineing.she broke her arm and was casted 7 days ago and yesterday we were at childrens hospital for her check up where she chewed on some community toys we were wondering if you had any ideas.is this something viral.sinus or related to her arm.p.s. she is also running a fever . she kinda looks like someone with bells palsy now (just to be descripitive)