This broad term refers to an unusual ” paradoxical” movement of the vocal cords in which rather than opening with a deep breath, they squeeze shut temporarily.  This problem can easily mimic asthma and may take years to diagnosis.  

If we think of the normal function of the vocal folds then we can better understand what vocal fold dysfunction is.  The vocal folds have three main functions:  Speech, airway protection and as a valve during normal breathing.  Therefore, vocal fold dysfunction may include a combination of dysphonia (difficulty with speech),  hypersensitivity to various environmental exposures (e.g.  bleach, perfumes) stimuli and/or shortenss of breath and coughing.

Classic vocal cord dysfunction is diagnosed by observation of glottic adduction during inspiration usually to the point that only a small posterior opening is visible.  This paradoxical closure is also evident on pulmonary function testing in the form of a truncated flow volume loop.  Most allergists know to look for VCD in asthmatics that are poorly responsive to therapy.  Many asthma mimics  do not meet the classic description of paradoxical vocal fold motion yet have respiratory symptoms of laryngeal origin.

There are a range of symptoms which may be confused with asthma or anaphylaxis that are in fact due to problems of the vocal folds.  This includes occasional patients who have a marked expiratory closure of the glottis (vocal cords) which on pulmonary function testing looks just like asthma.