My Seven Year Old Daughter Has Been Vomiting Since Thursday.

My seven year old daughter has been vomiting since Thursday. There was a period of about 12 hours today when she could keep food and liquids down but she began vomiting again at 7 p.m. (Four times since). Then she came up to me to show me that the lower left side of her lip was beginning to swell. She says she isn't having difficulty swallowing. Is this due to irritation or maybe something else?