VANCOUVER, B.C. — Both exercise-induced asthma and vocal cord dysfunction produce shortness of breath in young athletes, and being able to differentiate between them is key to ensuring appropriate treatment.
Exercise-induced asthma (EIA) is a well-established condition affecting at least 15%–20% of athletes, according to Dr. Joseph A. Congeni, medical director of sports medicine at Akron Children's Hospital, Ohio. In contrast, vocal cord dysfunction (VCD) is a more recently recognized condition affecting 2%–5% of young athletes, though “these numbers are continuing to go up.”
EIA affects the small airways, and its etiology is linked to dry air; allergens, pollutants, and irritants; and cold air, Dr. Congeni said at a meeting on pediatric and adolescent sports medicine sponsored by the American Academy of Pediatrics. Typically, it has multiple triggers besides exercise, but if exercise is the only or primary trigger, it is referred to as exercise-induced bronchospasm (EIB).
VCD affects the trachea, and its etiology is linked to laryngeal irritants, psychogenic disorders, and neurogenic conditions.
Because the two conditions produce overlapping symptoms, such as shortness of breath and cough, history is key to distinguishing them. Athletes with EIA may have wheezing, chest pain, and excess mucus production; their counterparts with VCD may have inspiratory stridor and voice changes, and may be pale or flushed. Of note, the cough of VCD is croupy and barklike.
“These kids sound like they are choking, and they can't catch their breath. It's very loud and noisy. EIA is not nearly as noisy,” said Dr. Congeni. “The VCD presentation may be much more dramatic” and these athletes can wind up in the emergency department.
The timing of symptoms also may help differentiate between the two conditions, he noted.
EIA/EIB can often be diagnosed with an exercise challenge test (in which a reduction of pulmonary function by at least 15% is diagnostic), a eucapnic voluntary hyperventilation challenge (the preferred method used by the International Olympic Committee), a pharmacologic challenge, or an osmotic challenge. However, all of these tests are plagued by an inability to reproduce field conditions and may therefore yield equivocal results, he said.
“VCD is difficult to diagnose, and it is a diagnosis of exclusion,” Dr. Congeni said. The best procedure for diagnosis is visualizing the cords while the athlete is symptomatic; however, it is rare to see attacks in the clinic. Pulmonary function testing may show a flattened or variable inspiratory curve—but this is seen clinically in only 20%–30% of cases. Other diagnoses that must be excluded are cardiac conditions, structural vocal cord abnormalities, and gastrointestinal reflux.
EIA/EIB is managed both with pharmacologic measures, primarily inhaled short-acting β2-agonists, and with nonpharmacologic measures. The latter include environmental alterations, masks, nose breathing, warm-up before exercise, and dietary manipulations, such as increasing the intake of caffeine and antioxidants, and decreasing the intake of salt.
A VCD attack is managed by urging the athlete to pant, to exhale making a soft “s” sound, and to use diaphragmatic breathing. Oxygen and sedatives may be given in the emergency department.
Education is essential to preventing future attacks of VCD, Dr. Congeni said, citing recommendations for management (Phys. Sportsmed. 1998;26:63–74).
These athletes also should be taken off any unnecessary medications. “Most have been on inhalers, which provide little, if any, benefit.”
The three therapies for VCD are speech therapy (which focuses on breathing patterns), psychotherapy, and relaxation therapy with biofeedback. Dr. Congeni reported he had no disclosures in association with his presentation.
Children with VCD 'sound like they're choking … It's very loud and noisy. EIA is not nearly as noisy.' DR. CONGENI