AUTHOR=Crawford A. L. , Blakey J. D. , Baumwol K. 

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

JOURNAL=Frontiers in Allergy

VOLUME=Volume 3 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/allergy/articles/10.3389/falgy.2022.1054791

DOI=10.3389/falgy.2022.1054791

ISSN=2673-6101

ABSTRACT=Paroxysms of dyspnoea in the general population are commonly reported and are frequently assumed to be asthma-related, especially if this diagnostic label has been previously applied. Often, this is not the case. Inducible Laryngeal Obstruction (ILO) and Dysfunctional Breathing (DB) are common comorbid conditions that go unrecognised in many difficult-to-treat asthmatics. On average, these patients have a delay in diagnosis of almost 5 years. This delay, along with ineffective, inappropriate escalation of asthma therapy, frequent hospital presentations for uncontrolled symptoms, and even intensive care admissions, magnifies patient morbidity and poor quality of life. 

ILO and DB have similar presentations and triggers to asthma. Differentiating between them can be challenging, especially in centres that do not have access to multidisciplinary subspecialty asthma services. Objectively confirming the diagnosis can likewise be challenging as symptoms fluctuate, and gold-standard investigations require extensive experience.

This mini-review will summarise the clinical features of ILO and DB, with particular focus in the context of individuals treated for asthma. This narrative with define each condition, highlight poignant aspects of the history and describe elements of the diagnostic pathway to gain objective confirmation.

Definition of terms: 
Inducible Laryngeal Obstruction: ERS/ELS statement 2017, ILO “… describes an inappropriate, transient, reversible narrowing of the larynx in response to external triggers”

Dysfunctional Breathing: Boulding et al (2016) “Dysfunctional breathing is a term describing breathing disorders where chronic changes in breathing pattern result in dyspnoea and other symptoms in the absence or in excess of the magnitude of physiological respiratory or cardiac disease”