Laryngoscopy diagnosis of inducible laryngeal obstruction during supervised challenge for suspected anaphylaxis

Abstract

Inducible Laryngeal Obstruction (ILO), also known as Vocal cord dysfunction (VCD) ─ episodic, paradoxical glottic closure during respiration ─ can mimic or even coexist with asthma.1– 3 Common triggers include inhaled irritants, odours and exercise.4 Proposed mechanisms include sensory neural dysfunction resulting in accentuation of the glottic closure reflex, which may be both irritant and stress mediated.5 It is less widely known that VCD also presents to allergists, mimicking anaphylaxis in response to allergen exposure via inhalation, ingestion or injection, and posing a diagnostic dilemma. Definitive diagnosis requires laryngoscopy confirmation of paradoxical vocal fold movement and exclusion of laryngeal angioedema, but this is rarely available during an acute episode.