Rash from food?

My daughter was eating lunch, nothing out of the normal except she has chocolate pudding. Also, it was in the fridge so super cold she clenched her side of her neck to her shoulder and shook like a brain freeze. I thought she was just playing around but it was the same side as the rash. I called her dr just to be safe and I’m waiting a for a call back. Any wine know what this could be?