What is the best course of action for a teenage girl with intermittent loss of voice and dyspnea (shortness of breath) during exercise, variable spirometry results ranging from normal to obstructive, no known allergies, and a family history of weak voice?

Exercise-Induced Laryngeal Dysfunction with Possible Familial Component

This teenage girl most likely has exercise-induced laryngeal dysfunction (EILD), specifically vocal cord dysfunction (VCD) or exercise-induced laryngomalacia, and requires continuous laryngoscopy during exercise challenge for definitive diagnosis, followed by speech therapy rather than asthma medications. 1

Why This is NOT Asthma

The clinical presentation strongly argues against exercise-induced bronchoconstriction (EIB):

• Symptoms occur and peak DURING exercise rather than 5-20 minutes after stopping, which is the hallmark timing for EIB 1
• Variable spirometry (normal to obstructive) suggests intermittent upper airway obstruction rather than consistent lower airway disease 2
• Loss of voice is a laryngeal symptom that does not occur with asthma 3
• Family history of weak voice suggests an inherited structural laryngeal abnormality, possibly laryngomalacia, which can be congenital but may not manifest until competitive sports participation 1
• Absence of allergies makes atopic asthma less likely 1

Diagnostic Approach

Immediate Next Steps

Perform continuous laryngoscopy during exercise challenge (treadmill or sport-specific activity) as the gold standard diagnostic test 1, 2, 4:

• This allows direct visualization of vocal cord adduction, arytenoid prolapse, or supraglottic collapse during symptomatic periods 1
• Laryngoscopy at rest will likely be normal, as these abnormalities are only elicited with exercise 1

Spirometry During Symptoms

Look for flattening or truncation of the inspiratory portion of the flow-volume loop during symptomatic periods 1, 2:

• This indicates variable extrathoracic airway obstruction, the signature finding of EILD 1
• Contrast this with asthma, which shows expiratory flow limitation 2

Key Diagnostic Features to Document

• Inspiratory stridor with throat tightness during maximal exercise that resolves within approximately 5 minutes of stopping 1
• Rapid symptom resolution after exercise cessation (unlike asthma, which peaks 5-20 minutes post-exercise) 1

Differential Diagnosis Considerations

Exercise-Induced Laryngomalacia (Most Likely Given Family History)

The family history of weak voice strongly suggests inherited laryngomalacia 1:

• Laryngomalacia involves diminished laryngeal tone causing supraglottic collapse 1
• Usually congenital but may not manifest until competitive sports participation 1
• Can present with profound arytenoid redundancy and prolapse on nasolaryngeal endoscopy 1
• Supraglottoplasty can improve late-onset disease 1

Vocal Cord Dysfunction (VCD)

VCD is more common in middle school to high school-aged athletes 1:

• Characterized by paradoxical vocal cord adduction during inspiration 1
• May coexist with laryngomalacia (the distinction between VCD and exercise-induced laryngomalacia in adolescents is clinically unclear) 1

Concurrent Laryngeal Abnormalities to Evaluate

Laryngoscopy should assess for 1:

• Gastroesophageal reflux disease (GERD) findings—posterior laryngeal changes are common in juveniles with VCD and warrant empiric treatment 1
• Chronic laryngitis 1
• Vocal cord motion impairment 1
• Nodules or subglottic stenosis 1

Critical Management Principles

What Will NOT Work

Beta-2 agonists and other asthma medications are completely ineffective for EILD 1, 2:

• Bronchodilators only work for lower airway bronchoconstriction, not upper airway mechanical obstruction 1
• Failure to respond to asthma medications is a key historical feature suggesting EILD 1, 2, 3

What WILL Work

Speech therapy is the cornerstone of treatment 5, 4:

• Teaches techniques to override dysfunctional breathing patterns 5
• Biofeedback plays a critical role 5
• Panting techniques can often abort acute attacks 6

If laryngomalacia is confirmed, supraglottoplasty may be indicated 1:

• Surgical intervention improves late-onset laryngomalacia just as it does in infants 1

Treat concurrent GERD empirically 1:

• Posterior laryngeal changes from GERD are common in juveniles with VCD 1
• Aggressive treatment of GERD, postnasal drip, or laryngopharyngeal reflux is warranted 1, 5

Common Pitfalls to Avoid

Misdiagnosis as Asthma

EILD is frequently misdiagnosed as asthma, leading to inappropriate corticosteroid overtreatment with consequent morbidity 5, 7:

• In one study of 142 patients with exercise-induced dyspnea, EIA was identified in only 11 of 117 who had symptoms reproduced during testing 7
• 98 of these patients had been previously diagnosed with asthma by referring physicians 7

Missing Coexistent Conditions

EILD can coexist with true EIB 1:

• Up to 20-40% of VCD patients also have asthma 3
• The presence of inspiratory stridor is the signature clinical feature distinguishing EILD from EIB 1

Timing of Diagnostic Testing

Laryngoscopy and spirometry must be performed DURING symptomatic periods 1:

• These findings are intermittent and will be normal between episodes 1, 5
• Continuous laryngoscopy during exercise is necessary to capture abnormalities 1, 2, 4

Prognosis and Long-Term Management

With appropriate diagnosis and multidisciplinary treatment (speech therapy, treatment of GERD, psychological support when needed), prognosis is usually good 5:

• Corticosteroids can often be discontinued once the correct diagnosis is established 5
• Quality of life and athletic performance significantly improve with proper management 2