Synopsis
Recognise inducible laryngeal obstruction and dangerous upper-airway mimics, confirm dynamic disease during symptoms, and replace unnecessary asthma escalation with specialist breathing and laryngeal care.
- Inducible laryngeal obstruction is the preferred term for transient inappropriate glottic or supraglottic closure during breathing; 'vocal cord dysfunction' is older and anatomically narrower.
- ILO episodes usually begin suddenly with inspiratory difficulty, throat tightness and noisy breathing after a trigger, then settle relatively quickly when the trigger stops.
- Asthma more typically causes expiratory airflow limitation and chest symptoms, but ILO and asthma commonly coexist, so an either-or assumption is unsafe.
- Laryngoscopy during a typical episode or controlled provocation is central to confirmation; a normal resting larynx does not exclude inducible disease.
- For exercise-triggered symptoms, continuous laryngoscopy during exercise is the reference dynamic test because closure may disappear within minutes of stopping.
- Inspiratory flattening on a flow-volume loop can support upper-airway obstruction but is insensitive for episodic ILO and must not be used as the sole diagnostic test.
- Speech and language therapy is core treatment, teaching laryngeal control, rescue breathing and trigger-specific strategies rather than simply offering reassurance.
- Treat confirmed asthma, rhinitis or another contributing disorder on its own evidence; do not escalate corticosteroid because an ILO attack sounds dramatic.
- Persistent or progressive stridor, voice change, dysphagia, haemoptysis, weight loss or symptoms during sleep require structural and neurological assessment rather than an ILO label.
- A patient-recorded audio or video can clarify timing and sound, but it supports history and does not replace examination or symptom-provoked laryngoscopy.
Key red flags
Acute airway or breathing difficulty with urticaria, flushing, hypotension, gastrointestinal symptoms or known allergen exposure is anaphylaxis until treated, even when throat tightness resembles previous ILO.
Progressive or persistent stridor, voice change, dysphagia, neck mass, haemoptysis, weight loss, sleep symptoms or a fixed flow-volume-loop abnormality requires urgent ENT and airway imaging assessment.
Persistent dysphonia, aspiration, weak cough or stridor after neck or thoracic surgery, intubation or neurological disease may reflect vocal-fold paresis rather than inducible closure.
Investigation priorities
Identify immediate airway danger and localise airflow limitation.
Management branches
A patient presents with acute throat tightness, noisy breathing or apparent upper-airway obstruction.
- Perform ABCDE and look for swelling, rash, hypotension, foreign-body history, infection, trauma, voice change, hypoxaemia, exhaustion and altered consciousness.
- Call anaesthetic and ENT support early for threatened airway; treat anaphylaxis immediately with intramuscular adrenaline and follow the local emergency algorithm.
- If observations are stable and the episode matches established ILO, reduce unnecessary stimulation and coach only the person's previously taught rescue-breathing strategy.
- Reassess physiology and alternative diagnoses after symptoms settle; response to reassurance or bronchodilator alone does not prove the mechanism.