Management of Exertional Shortness of Breath in an 8-Year-Old Child
For an 8-year-old child with exertional dyspnea, the first step should be cardiopulmonary exercise testing to determine whether the shortness of breath is due to exercise-induced bronchoconstriction (EIB), dysfunctional breathing, or reaching physiological limits. 1, 2
Diagnostic Approach
- Perform spirometry and detailed pulmonary examination to determine if shortness of breath is associated with underlying conditions such as restrictive lung conditions or exercise-induced bronchoconstriction 1
- Conduct an indirect challenge test (exercise challenge) rather than direct challenge (methacholine) for assessing EIB, as indirect challenges are more sensitive for detection 1
- For exercise challenge testing, ensure heart rate reaches and sustains at least 95% of maximum heart rate in children 1
- Consider cardiopulmonary exercise testing to determine if exercise-induced dyspnea and hyperventilation are masquerading as asthma, which is common in children and adolescents 1
- Differentiate between EIB and exercise-induced laryngeal dysfunction (EILD) through appropriate challenge tests and potentially flexible laryngoscopy during exercise 1
Differential Diagnosis
Common causes of exertional dyspnea in children:
- Exercise-induced bronchoconstriction (EIB) 1
- Dysfunctional breathing (including breathing pattern disorder and inducible laryngeal obstruction) 2, 3
- Poor physical conditioning (most common reason for exercise-induced dyspnea in children) 1, 2
- Exercise-induced laryngeal dysfunction (EILD) 1
- Exercise-induced anaphylaxis (EIAna) - consider when respiratory symptoms are accompanied by systemic symptoms like pruritis, urticaria, and hypotension 1
- Cardiac causes - refer to cardiologist when breathlessness with exercise might be caused by heart disease 1, 4
- Structural abnormalities - such as subglottic stenosis 5
Management Approach
For Exercise-Induced Bronchoconstriction:
- Prescribe inhaled short-acting β2-adrenergic receptor agonists (SABAs) like albuterol for protection against EIB and for accelerating recovery of pulmonary function 1, 6
- Use a single dose of SABA on an intermittent basis (less than 4 times per week) before exercise to protect against or attenuate EIB 1
- Be cautious with daily use of β2-adrenergic agents as this can lead to tolerance manifested as reduced protection against EIB 1
- Schedule regular follow-up visits as medications can differ in effectiveness over time due to variability of asthma, environmental conditions, and intensity of exercise 1
For Dysfunctional Breathing:
- Refer to an experienced physiotherapist, speech and language therapist, or psychologist depending on the dominant features of presentation 3
- Implement breathing retraining and vocal exercises rather than medication therapy 2
- Ensure associated conditions such as asthma, extra-esophageal reflux, rhinitis, and allergies are well-controlled before starting directed therapy for dysfunctional breathing 3
For Poor Physical Conditioning:
- Provide reassurance and advice on gradual increase in physical activity 2
- Implement a structured exercise program to improve conditioning 2, 4
Important Considerations
- Avoid misdiagnosis of asthma in cases of dysfunctional breathing or reaching physiological limits, as this leads to unnecessary medication use 2, 3
- For children with obesity, recognize that dyspnea may be associated with increased oxygen cost of breathing without bronchoconstriction 1, 4
- Monitor for signs of exercise-induced anaphylaxis, which can present with respiratory symptoms plus systemic manifestations 1
- If symptoms persist despite appropriate management, refer to appropriate specialists (pulmonologist, cardiologist) for further evaluation 1