Vocal cord dysfunction: beyond severe asthma.

BACKGROUND

Vocal cord dysfunction (VCD) is the abnormal adduction of the vocal cords during inspiration causing extrathoracic airway obstruction. VCD has been described as a confounder of severe asthma. The influence of VCD among less severe asthmatics has not been previously defined.

METHODS

We retrospectively reviewed the medical records of 59 patients with pulmonologist-diagnosed asthma who were referred for videolaryngostroboscopy (VLS) testing from 2006 to 2007.

RESULTS

A total of 44 patients had both asthma and VCD. 15 patients had asthma without concomitant VCD. Females were predominant in both groups. Overall, the majority of patients referred for VLS testing had mild-to-moderate asthma (78%) and 72% of these patients had VCD. Few patients from either group had "classic" VCD symptoms of stridor or hoarseness. Gastroesophageal reflux disease (GERD) and rhinitis were common in both groups.

CONCLUSIONS

Vocal cord dysfunction occurs across the spectrum of asthma severity. There was a lack of previously described "classic" VCD symptoms among asthmatics. Symptoms were diverse and not easily distinguished from common symptoms of asthma, highlighting the need for a high index of suspicion for VCD in patients with asthma. Failure to consider and diagnose VCD may result in misleading assumptions about asthma control, and result in unnecessary adjustments of asthma medications. The high prevalence of GERD raises the question of the role of acid reflux in the pathogenesis of VCD in asthmatics.