My Sister Takes Buesonide For Crohns Disease. She Has Been

My sister takes Buesonide for crohns disease. She has been on the medication for almost a year. For the past couple of weeks, she has broken out in hives and today, she said it feels as if her throat is closing. Could this be a side effect of the medicaton? Should she go to the emergency room, or wait to contact her doctor in the morning? Thank you