Vocal cord dysfunction masquerading as exercise-induced asthma. a physiologic cause for "choking" during athletic activities.

Exercise-induced bronchospasm is a common clinical problem that is particularly troubling for patients who engage in strenuous physical activity, such as athletes. When such individuals develop this condition, the associated airway narrowing can materially interfere with performance; however, events other than asthma can also produce these symptoms and their differentiation is essential for proper treatment. The present report describes seven elite athletes with psychogenic vocal cord dysfunction who presented with acute dyspnea during sporting competitions. Although the combination of exertion and wheezing suggested the diagnosis of exercise-induced asthma, the patients' histories were sufficiently unique so as to represent a recognizable syndrome. The patients underwent clinical physiologic evaluations including bronchoprovocations with isocapnic hyperventilation of frigid air, methacholine and/or exercise. Direct laryngoscopy was also performed in some subjects. The findings that differentiated these patients from asthmatics were a lack of consistency in the development of symptoms when exposed to identical stimuli, the onset of breathing difficulties during exercise, and poor therapeutic and prophylactic responses to anti-asthma medications. The clinical impression of a functional disorder was confirmed by bronchoprovocations that demonstrated the variable extrathoracic airway obstruction of vocal cord dysfunction. Patients with atypical exertional complaints require careful clinical and physiologic evaluation. The mere association of exercise and airway obstruction is not sufficient to establish the diagnosis of asthma.