Abstract and Introduction
Vocal cord dysfunction (VCD) is the abnormal adduction of the vocal cords during inspiration or expiration that results in varying degrees of airway obstruction. VCD is more common in females and usually presents during childhood or adolescence and continues up to age 40 years. Studies have found an increased prevalence of VCD in female athletes and academic high-achievers compared with the general population. VCD is often misdiagnosed as asthma or exercise-induced bronchospasms (EIB) because of similarities in clinical presentation. Since misdiagnosis results in inappropriate pharmacotherapy, it is important for the pharmacist to have a thorough understanding of VCD in order to differentiate it from asthma and EIB.
Vocal cord dysfunction (VCD) is the abnormal adduction of the vocal cords during inspiration or expiration that results in varying degrees of airway obstruction.[1–3] First described in 1842 as a disorder of the laryngeal muscles brought on by "hysteria" and subsequently observed by laryngoscopy in 1869, VCD was called hystericcroup, Munchausen's stridor, and psychogenic stridor because the etiology was assumed to be psychological.[4,5] It is now recognized that VCD is not solely psychological; therefore, the terminology has evolved to include factitious asthma, irritablelarynx syndrome, paradoxicalvocal-fold motion, paradoxical vocal cord dysfunction, and refractory asthma.[4,6,7] The clinical presentation of VCD involves wheezing, stridor, change in vocal quality, dyspnea (including upon exertion), chest tightness, cough, respiratory distress, and choking sensations.[1,3,4,8] VCD, which occurs more often in females, especially athletes, usually presents in childhood or adolescence and lasts to age 40 years.[3,4]
VCD is often misdiagnosed as asthma or exerciseinduced bronchospasms (EIB) because of similarities in clinical presentation. The misdiagnosis is often discovered after asthma pharmacotherapy fails to control symptoms. To avoid inappropriate pharmacotherapy, pharmacists must be able to differentiate between asthma, EIB, and VCD. The diagnostic gold standard for VCD is laryngoscopy during an attack.
It is possible for a person to have concomitant asthma or EIB with VCD, which makes diagnosis more difficult. Studies have found an increased prevalence of asthma and EIB in athletes (recreational or elite) and academic high-achievers compared with the general population.[1,10] The female-to-male ratio for VCD prevalence ranges from 2:1 to 3:1.[9,11,12]
US Pharmacist. 2017;42(9):34-39. © 2017 Jobson Publishing