mrcem2-0673

A 5-year-old girl is brought into the Emergency Department with stomach pain and throwing up. Her mom tells you that she has been losing weight lately and seems to be drinking a lot and peeing a lot. During the examination, she appears tired and you notice that she is dehydrated. She is breathing deeply and quickly. Her blood sugar levels are found to be extremely high when her blood is tested.
What is the MOST likely diagnosis?