Prevalence of Inducible Laryngeal Obstruction among Patients Diagnosed as Bronchial Asthma

Abstract

Introduction: Inducible laryngeal obstruction (ILO) is an important cause of a variety of respiratory symptoms and can mimic bronchial asthma (BA). This study was planned to measure the prevalence of ILO among patients diagnosed with BA and to detect its effect on BA control and severity. Material and methods: Patients aged 18 years or older who were previously diagnosed with BA were enrolled. Laryngeal obstruction was induced using the patient’s specific trigger (e.g. exercise). Visualization of vocal folds was accomplished using a 70-degree rigid laryngoscope (Karl Storz). A visual grade score was utilized to determine the severity of laryngeal obstruction. Results: Results showed that 38.3% (n = 46) of the patients had ILO with the majority being classified as grade 2 (80.4%) (n = 37). The most common subtype was glottic ILO (63%). Bronchial asthma duration, level of control, and severity were not associated with ILO (P values: 0.2, 0.3 and 0.8 respectively). Conclusion: Asthma and ILO commonly co-exist. An accurate classification of patients is very important and must be considered in order to determine whether the symptoms are directly related to ILO or whether they are caused by BA. Ceasing inappropriate treatment may be necessary. Objective diagnostic modalities of ILO are essential.

Prevalence and impact of exercise-induced laryngeal obstruction in asthma: a study protocol for a cross-sectional and longitudinal study

“…Hull et al found similar asthma control scores in patients with normal and abnormal laryngeal function 3. Similar findings were reported by Abdelwahab et al , with no differences in asthma control, irrespective of comorbid EILO 13. Walsted et al found no relationship between comorbid EILO and asthma-related QoL 12.…”

“…The two conditions are diagnosed differently, with an EIB test or a continuous laryngoscopy exercise (CLE) test, respectively 8 9. The CLE test has been conducted on few patients with asthma, as most of the individuals previously studied have been young and otherwise healthy athletes, and few studies have specifically enrolled patients with asthma 7 10–14. Thus, the prevalence estimates of EILO in the asthmatic populations remain uncertain.…”

“… 3 Similar findings were reported by Abdelwahab et al , with no differences in asthma control, irrespective of comorbid EILO. 13 Walsted et al found no relationship between comorbid EILO and asthma-related QoL. 12 Contradicting these studies, Parsons et al studied 59 patients with asthma and found decreased disease control in patients with comorbid glottic obstruction.…”

Untangling asthma, inducible laryngeal obstruction, and dysfunctional breathing in a competitive sportsperson

“…Uncontrolled asthma is common in Australia, partly due to undertreatment, severe disease, and unrecognized contributory comorbidities 1,2 . Inducible laryngeal obstruction (ILO) and dysfunctional breathing (DB) are recognized drivers of poor symptom control 3–5 . Guidelines recommend structured multidisciplinary assessment to identify and address issues systematically 2,6–8 .…”

Paroxysmal dyspnoea in asthma: Wheeze, ILO or dysfunctional breathing?

“…It can be challenging however, to differentiate asthma symptoms from those caused by dysfunctional breathing pattern disorder (DB) and inducible laryngeal obstruction (ILO). These conditions appear comorbidly with asthma relatively commonly, with described prevalence in asthmatics ranging from 19 to 38% for ILO ( 14 , 15 ), and 29% for DB ( 16 ).…”