A 16-year-old girl comes to the office with shortness of breath. She has not been able to participate in weekly soccer practice for the last few months due to dyspnea and chest tightness. Her symptoms start 10-15 minutes after beginning exercise and last about 30 minutes, but she is asymptomatic at other times. The patient has no known medical problems. Her brother has ostium secundum atrial septal defect and her mother has allergic rhinitis. Vesicular breath sounds are heard on lung examination. Cardiac auscultation reveals normal splitting of second heart sound in the left upper sternal border during inspiration and no murmurs. Jugular venous pressure is estimated at 5 cm H₂O. There is no lower extremity edema. Which of the following is the most appropriate next step in managing this patient?

Question

Quizplus · Accepted Answer

Explanation: This patient's symptoms suggest exercise-induced bronchoconstriction (EIB). EIB may occur in asthmatics or in patients without a pre-existing diagnosis of asthma. Bronchial smooth muscle constriction may be triggered by exertion or passage of large volumes of dry cold air causing mast cell degranulation. Patients with EIB may be otherwise asymptomatic. Clinical symptoms are not sufficient to make a diagnosis of EIB, and bronchoprovocation testing with exercise or inhalation of dry, cold air is recommended. A fall in forced expiratory volume in 1 second of >10% is considered positive; a fall >15% is diagnostic. Pre-exercise warm-up may be sufficient to prevent EIB in those with only occasional symptoms. Patients with persistent symptoms who exercise infrequently (less than daily) requireshort-acting β2-agonists (SABAs) 10-20 minutes before exercise. Mast cell stabilizers (cromolyn sodium or nedocromil) may be used in patients who do not tolerate SABAs. Athletes who exercise frequently should be started on daily inhaled corticosteroids with SABAs as needed (Choice B). (Choice C) Echocardiogram with bubble study will diagnose structural heart disease and septal defects. Symptomatic septal defects produce fixed splitting of the second heart sound and possibly audible murmurs, which are detectable on examination. This patient has normal cardiac examination findings. (Choice D) Exertional dyspnea may be caused by any etiology of interstitial lung disease. Crackles are usually heard on lung examination in these patients. A high-resolution chest CT scan may be helpful in diagnosing these disorders. However, this patient has a completely normal lung examination. (Choice E) Exertional dyspnea with chest tightness in this age group is concerning for left ventricular outflow tract (LVOT) obstruction. Patients with symptomatic LVOT obstruction will likely have a systolic murmur that accentuates with Valsalva maneuver. Stress testing is used in the risk stratification of LVOT obstruction. Educational objective: Exercise-induced bronchoconstriction (EIB) can occur with or without pre-existing asthma. Diagnosis is made with bronchoprovocation testing. Treatment includes pre-exercise warm-up for infrequent EIB, short-acting β2-agonists for persistent symptoms, and daily inhaled corticosteroids for those requiring daily β2-agonist therapy. References: Exercise-induced bronchospasm diagnosis in children. utility of combined lung function tests. (http://www.ncbi.nlm.nih.gov/pubmed/25444583) Diagnostic exercise challenge testing. (http://www.ncbi.nlm.nih.gov/pubmed/21915675)

A 16-Year-Old Girl Comes to the Office with Shortness of Breath