DIANA MAHONEY (New England Bureau)
BOSTON — Although asthma is a common cause of exercise-induced shortness of breath in children and adolescents, “it is not the only cause,” said pediatric pulmonologist Christina Scirica. “Failing to consider other possibilities can lead to mismanagement and the inappropriate use of medications.”

Cardiac disease, vocal cord dysfunction, restrictive physiology, anemia, anxiety, deconditioning from habitually low levels of activity, and normal breathlessness associated with extreme exercise are among the potential causes of exertional dyspnea in children, Dr. Scirica said at a meeting on primary care pediatrics sponsored by Harvard Medical School.
In fact, she noted, studies have shown that children with exercise-induced shortness of breath (SOB) who have no other asthma symptoms and normal pre-exercise lung function, and who don't respond to simplest asthma treatment measures, such as the use of a bronchodilator inhaler, often don't have asthma, despite being diagnosed with it, said Dr. Scirica of Boston's Massachusetts General Hospital.

Dr. Scirica offered a cognitive framework consisting of a series of questions to ask oneself while eliciting the patient history and conducting the examination. “In a nutshell,” she advised, “ask yourself, in this order: Does this sound like cardiac disease? Does this sound like vocal cord dysfunction? Does this sound like exercise-induced asthma? Does this sound like none of the above?”

Consider cardiac disease if the patient describes associated symptoms such as chest pain, dizziness, lightheadedness, or palpitations, or if there is a personal or family history of cardiac disease or an abnormal cardiac exam, Dr. Scirica said. A “yes” to any of these should prompt an electrocardiogram, a Holter study, and a referral to a cardiologist.
Described as paradoxical closure of vocal cords during inspiration, vocal cord dysfunction can cause SOB associated with throat tightness and inspiratory stridor, according to Dr. Scirica. One clue that exertional dyspnea might be linked to vocal cord dysfunction, she said, “is a lack of response to a-agonist therapy.” Patients with suspected vocal cord dysfunction should be referred to an ear, nose, and throat specialist for evaluation. “Visible adduction [via laryngoscopic examination] of the vocal cords during inspiration is the diagnostic gold standard,” said Dr. Scirica. Treatment for this condition includes vocal cord training by a speech therapist and, when necessary, psychiatric treatment for the underlying anxiety.
The tell-tale symptoms of asthma—expiratory, breathy wheezing, and cough—that occur during or after exercise and require 5–6 minutes of 80%–85% effort may signal exercise-induced asthma, said Dr. Scirica. “The symptoms may be exacerbated by such factors as cold air exposure, high pollen count, or upper respiratory infection,” she said, and are more likely in children with a past medical history of asthma or allergic rhinitis or a family history of asthma.

Exercise-induced asthma is responsive to corticosteroid and a-agonist therapy, said Dr. Scirica, noting, however, “that the a-agonist must be given 15–20 minutes prior to exercise and should be administered via a spacer.” Prevention strategies, such as pre-exercise warm up to induce refractory period and avoidance of environmental triggers—should also be encouraged. When a child or adolescent with presumed exercise-induced asthma does not respond to treatment or develops atypical symptoms, referral to a pulmonologist is warranted, she said.
When symptoms associated with the experience of exertional dyspnea are not suggestive of cardiac disease, vocal cord dysfunction, or asthma—or the symptoms are consistent with asthma but do not respond to appropriate therapy, “consider a referral to pulmonology for further evaluation,” which will likely include a clinical consultation, pulmonary function testing, treadmill test for exercise-induced asthma, and/or cardiopulmonary exercise testing, concluded Dr. Scirica, who reported no relevant conflicts of interest with respect to her presentation.