Differential Diagnosis
According to The American College of Chest Physicians (CHEST) guidelines and Expert Panel Report, the differential diagnosis of cough occurring in athletes over 12 years of age are EIB, asthma, respiratory tract infections and upper airway cough syndrome due to rhinosinusitis. Environmental factors that may significantly affect lung function should also be taken into consideration26.
In a differential diagnosis of a young athlete presenting with breathing difficulties, laryngeal wheeze during physical effort, dyspnea and cough, exercise-induced vocal cord dysfunction (VCD) should also be taken into consideration. Exercise-induced VCD affects up to 5-27% of patients earlier diagnosed with EIB. In such cases during physical effort, paradoxical motion of the vocal cords occurs, especially during inspiration27. Particularly, patients with difficult-to-treat asthma and athletes whose symptoms do not improve after treatment should be considered in the differentiation from exercise-induced VCD. Exercise-induced laryngomalacia may be another presenting condition. In both cases FEV1 does not decrease after exercise or after the administration of ß2-mimetics and / or inhaled GKS.
Dysfunctional breathing (activation of additional inspiratory muscles, with shallow breathing, and lifting of the chest wall), acquired and habitual patterns of breathing, should also be considered in differentiating EIB among young athletes. Dysfunctional breathing often occurs in people with asthma. It is characterized by the absence of any functional airway disorder, exercise-induced hyperventilation, and often co-occurs with acute anxiety. As a result of hyperventilation, respiratory alkalosis occurs, causing dyspnea, light-headedness, chest tightness and paraesthesias.
When investigating dyspnea, it is widely emphasized to take psychological factors into consideration, especially when working with young patients. This is because dyspnea is a subjective measurement and the symptoms that occur during exercise can be interpreted differently.
Rare pathologies causing exercise-induced symptoms, especially in adolescent athletes, include hypertrophic cardiomyopathy (HCM), which is the main cause of sudden cardiac death in this group. Other rare pathologies that simulate EIB symptoms include: exercise-induced arrhythmia, cardiovascular dysfunctions, pulmonary embolism, anemia, interstitial lung disease, swimming induced pulmonary edema, exercise-induced anaphylaxis, and myopathies.