Spiraling Out of Control.

A 22-year-old man presented to the emergency department on Christmas Day with a 5-day history of myalgias, cough, dyspnea, nonbilious emesis, and nonbloody diarrhea. Although he had been ill for several days, he ultimately sought treatment because of intractable vomiting. He reported feeling feverish, although he had not measured his temperature, and noted one episode of hemoptysis.