Vocal Cord Dysfunction: An Often-misdiagnosed Condition

Sarah M. Jabusch, MS Clinical Research; Timothy M. Hinson, PharmD, AE-C

Disclosures

US Pharmacist. 2017;42(9):34-39. 

In This Article

VCD Etiology

The cause of VCD may be multifactorial. VCD may be triggered by many factors that also trigger asthma or EIB. The major exacerbating factors include exercise, airborne irritants, postnasal drip (PND), gastroesophageal reflux disease (GERD), laryngopharyngeal reflux (LPR), and certain medications.

Exercise. Exercise can trigger both VCD and EIB, making diagnosis difficult. When a patient presents with dyspnea upon exertion and is not achieving symptom control with bronchodilators, VCD should be included in the differential.[3,10] This is important because in 96% of subjects in one study who participated in sports, the most common primary respiratory complaint was dyspnea upon exertion and the most common diagnosis was VCD (in 70%).[10] Respiratory symptoms associated with exercise occurred more frequently in younger athletes than in college athletes, and VCD was more common in females.[10] Other activities, such as talking, laughing, deep breathing, and swallowing, also can trigger VCD.[17]

Airborne Irritants. Exposure to respiratory irritants has been implicated in both VCD and asthma. In patients with asthma, this is classified as irritantinducedasthma.[18] Acute or recurrent irritant exposure could lead to laryngeal hypersensitivity and result in VCD.[16] Patients should be questioned on the temporal relationship of their exposure to strong odors and substances such as perfumes, dust or particulate matter, smoke, smoldering fumes, and household cleaning chemicals and the onset of VCD symptoms.[3,6] One irritant associated with VCD, especially in swimmers and divers, is chlorine.[6] Athletes with known allergies or rhinitis should avoid training environments with high levels of airborne allergens.[19]

PND. PND can cause direct irritation of the vocal cords, resulting in VCD.[15] Common disease states associated with PND include allergic and nonallergic rhinitis, maxillofacial sinus infections, and rhinosinusitis.[3] Often these are chronic disease states, and patients therefore assume that PND is normal. PND causes airway hyperresponsiveness, especially in patients with rhinosinusitis.[3] Upon diagnosis, treatment may require months before symptoms resolve.[20]

GERD and LPR. GERD has been estimated to be as high as 60% in the general population and has been associated with VCD and asthma.[21] The precise mechanism of GERD in VCD has not been fully elucidated, but is thought to be secondary to laryngeal damage. Symptoms of GERD include throat-clearing, hoarseness, chronic cough, heartburn, burning sensation in the throat, acid regurgitation, chest pain, and wheezing.[21,22] Treatment of GERD to improve VCD symptoms is helpful only in some patients.[3]

LPR is the retrograde flow of gastric secretions into the laryngopharynx, which is highly susceptible to these secretions.[21] Upon repeated contact with the laryngeal mucosa, these gastric secretions can cause laryngeal inflammation, resulting in VCD.[21] Chronic PND and LPR may lead to increased laryngeal sensitivity and subsequent laryngeal hyperresponsiveness.[21] Symptoms of LPR include persistent throat irritation and tightness, excessive mucus production, dyspnea, and stridor.[23] Dyspepsia and heartburn are less common in LPR.[23]

Patients with VCD may not report classic symptoms of acid reflux or heartburn even in the presence of laryngoscopic evidence of laryngeal inflammation.[6]

Medications. Extrapyramidal signs, such as torticollis, are associated with neuroleptic drugs and metoclopramide, which may result in a focal dystonic reaction and have been reported to lead to VCD.[3,24] These events are rare; however, the pharmacist should conduct a thorough medication review in patients presenting with symptoms of VCD.[12,25]

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