Although an important cause of vocal cord dysfunction (VCD) is psychogenic reaction, VCD may be associated with severe asthma and must be distinguished from the disease. A 30-years-old woman was admitted to our hospital with dyspnea despite treatment for asthma. Inspiratory stridor and expiratory wheezes were noted, and neck and chest computed tomography showed normal airways and lungs. Fractional exhaled nitric oxide levels were also normal. Pulmonary function test with a flow-volume loop curve showed normal expiratory loop with flattening of the inspiratory loop after methacholine inhalation. During the attack, bronchoscopy revealed the vocal cord closing with stridor during the inspiratory phase. Therefore, the patient was diagnosed with VCD. The dyspnea improved with respiratory rehabilitation and pursed-lip breathing. VCD should be considered in the differential diagnosis of intractable severe asthma. In this case, bronchoscopy and bronchial inhalation challenge with methacholine helped in the diagnosis.
Keywords: airway hyperresponsiveness; bronchial asthma; bronchoscopy; pursed-lip breathing; vocal code dysfunction.