East Coast physicians report finding 11 patients who experience a strange set of exercise-associated symptoms that are potentially fatal. The investigators, from Harvard Medical School and Albany Medical College, reported their findings at the meeting of the American Academy of Allergy in New Orleans. The seven male and four female patients range in age from 11 to 45 years, are well-conditioned, accomplished athletes, and participate in sports such as sprinting and long-distance running, soccer, basketball, football, and tennis. During or following exercise, nine have had syncopal episodes—some of which have been almost fatal—with cutaneous angioedema involving the face, palms, and soles. Five also have had upper respiratory tract obstruction with choking and stridor. Gastrointestinal symptoms have occurred in five patients, usually with nausea, and three have severe headaches lasting several days. All 11 patients experienced pruritus, often followed by urticaria. Each athlete has had from one to 20 such attacks.