Vocal cord dysfunction in patients with asthma
Published: October 27, 2021
Vocal Cord Dysfunction (VCD), also known as inducible laryngeal obstruction, refers to paradoxical vocal fold closure during respiration. In the presence of compatible clinical features, definitive diagnosis of VCD requires objective visualization of paradoxical vocal fold movement, usually by direct laryngoscopic examination. VCD is present in between 25-50% of patients with asthma and differentiating the two conditions is challenging clinically. The presence of VCD in severe asthma is associated with frequent exacerbations, poorer quality of life and increased health care utilisation. When mistaken for asthma, VCD has been associated with high medication usage and invasive interventions.
In a recent article in The Journal of Allergy and Clinical Immunology: In Practice, Stojanovic et al. reported on the diagnostic and therapeutic outcomes of 212 consecutive patients who underwent systematic evaluation and multidisciplinary management for suspected concurrent VCD and asthma over a five-year period at their tertiary academic center. Criteria for referral to their systematic evaluation protocol included 1) where the diagnoses of asthma plus VCD was uncertain and 2) where the respective contribution of each diagnosis to symptomatology was unclear. Evaluation and management were delivered with an initial clinic visit, diagnostic testing, speech pathology intervention and second clinic visit after 4 to 6 months. VCD was confirmed by visualization of paradoxical vocal fold motion at baseline or following provocation. Asthma was confirmed by demonstrating variable airflow obstruction. Asthma medications were deescalated in those with low clinical probability of asthma and no variable airflow obstruction. Response to 2 or more sessions of speech pathology was assessed by subjective report and standardized questionnaires.
Stojanovic and colleagues reported that among 212 consecutive patients, 62 (29%) patients had both VCD and asthma, 54 (26%) had VCD alone, 51 (24%) had asthma alone, and 45 (21%) had neither. Clinician assessment and the Laryngeal Hypersensitivity Questionnaire both predicted laryngoscopy-confirmed VCD. De-escalation or discontinuation of asthma therapy was possible in 37 of 59 (63%) patients without variable airflow obstruction, and was most successful (odds ratio, 5.5) in the presence of laryngoscopy confirmed VCD (25 of 31, or 81%). Patients with VCD responded subjectively to 2 or more sessions of speech pathology, but subjective symptom improvement following speech pathology was not paralleled by improvements in laryngeal questionnaire scores.
Overall, these findings suggest that expert clinician assessment and the Laryngeal Hypersensitivity Questionnaire predict the presence of laryngoscopy-confirmed VCD, and systematic assessment for both VCD and asthma facilitates de-escalation or discontinuation of unnecessary asthma medications. The ability of standardised questionnaires to assess response to speech pathology in patients with dual diagnoses requires further assessment
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.