My Daughter 28 Year Old Was In The ER For

My daughter 28 year old was in the ER for severe abdominal and back pain as well as vomiting. She was given Cipro and Flagyl for intestinal bacteria possible appendicitis. After taking Cipro for 2 days she has hive rash only on left arm. That is where the blood pressure cuff was. Flagyl was IV one hour in the ER then 2 oral doses today. Do you think because the rash is only on the left arm it is an allergic reaction to medication? I am an LPN as well.
Thank you, Kathy