A teen arrived at the emergency room with an array of symptoms, including vomiting, recent unexplained weight loss, and unusual thirst. It turned out she had an uncommon autoimmune syndrome. (Image credit: Douglas Sacha via Getty Images) The patient: A 17-year-old girl in California The symptoms: The teenager went to an emergency department after experiencing vomiting episodes for about a day. Over the prior three months, she'd also had periodic shortness of breath accompanied by tightness in her chest. Doctors learned that the patient had also experienced unusual thirst, excessive urination, unexplained weight loss and fatigue. Based on these symptoms and the high blood sugar, the doctors determined the patient likely had type 1 diabetes and admitted her to the pediatric department for further tests. They started her on a conservative dose of insulin, but despite that, she often experienced low blood sugar in the mornings.…