Seeing the Forest Through the Wheeze: A Case-Study Approach to Diagnosing Paradoxical Vocal-Cord Dysfunction

Abstract

OBJECTIVE: To present for discussion a case of paradoxical vocal-cord dysfunction (PVCD), an uncommon disorder that may be misdiagnosed as, or coexist with, exercise-induced asthma (EIA). BACKGROUND: Vocal-cord dysfunction results from paradoxical closure of the vocal cords during the inspiratory phase of respiration and may be mistaken for EIA, resulting in unnecessary medical treatment and a delay in diagnosis. Although PVCD is uncommon, athletic trainers should be aware of the disorder, as they may play an important role in its diagnosis and treatment. DIFFERENTIAL DIAGNOSIS: Exercise-induced asthma, foreign body aspiration, anaphylactic laryngeal edema, bilateral vocal cord paralysis, extrinsic airway compression, laryngomalacia, subglottic stenosis, traumatic edema, or hemorrhage. UNIQUENESS: This case report describes a common presentation of an unusual disorder. By obtaining a detailed history from the athlete and having a high index of suspicion for the disease, we were able to diagnose PVCD, discontinue all EIA medications, and begin treatment. CONCLUSIONS: The athletic trainer can play a valuable role in the diagnosis of PVCD, which must be considered in the differential diagnosis for any athlete who is compliant with the medications prescribed for the treatment of EIA yet shows little or no improvement in symptoms. A high index of suspicion for PVCD will greatly aid health care professionals assessing the athlete.

Figure 1

Pulmonary function test results before exercise. Note the abnormal inspiratory loop (inferior to the Y-axis).

Figure 2

Normal flow-loop diagram seen with pulmonary function testing.