A rare cause of vomiting in a 5-year-old girl

A 5-year-old previously healthy girl presented to the emergency department (ED) with vomiting for 6 days. Her activity level was normal but her parents described progressive exercise intolerance with frequent recreational breaks approximately 2 days prior to presentation. In addition, the child complained of mild abdominal discomfort that began 24 hours prior to her presentation. She had no diarrhea or changes in her diet or oral intake; she had no dysuria or changes in urination. She had no cough, shortness of breath, dizziness, vision changes, falls, or decreased coordination.