When It's Not Just ILO: Why Differential Diagnosis Changes Everything

Inducible laryngeal obstruction is complex — and it rarely travels alone. Here's what every patient with breathing difficulties deserves to know before starting treatment.

If you've been struggling to breathe and finally received a diagnosis of inducible laryngeal obstruction (ILO), you may feel relieved to have a name for what's been happening. But here's something your care team should tell you: ILO is one of the most frequently misidentified and misunderstood conditions in upper airway medicine and getting the diagnosis right is the foundation of effective treatment.

At our practice, we specialize in upper airway disorders, and we see firsthand how often patients arrive with an ILO diagnosis that tells only part of the story. Understanding what ILO is, what it can look like, and what else might be going on alongside it are the questions that guide genuinely effective care.

What is ILO, exactly?

ILO is characterized by an inappropriate, transient narrowing of the larynx in response to external triggers. Unlike asthma — which causes difficulty exhaling — ILO primarily causes difficulty inhaling, often accompanied by a sensation of tightness at the throat. Events may be sudden, alarming, and sometimes severe enough to prompt an emergency room visit.

The condition has gone by many names over the years: vocal cord dysfunction, paradoxical vocal fold motion, and others. The term ILO is now the preferred umbrella term because it best captures the defining features of the disorder.

Key distinction: ILO events are episodic and triggered — they begin before feelings of panic set in, and they resolve. This is one of the most important features that helps differentiate ILO from other conditions that may look identical on the surface.

The conditions most commonly confused with ILO

Here's what makes ILO clinically challenging: there are numerous conditions that can mimic it, co-occur with it, or be masked by it. Research shows that around 25% of adults with ILO also have co-occurring asthma — and some patients have three or more concurrent diagnoses affecting the upper airway simultaneously.

• Asthma: Most common mimic; causes difficulty exhaling, not inhaling

• Angioedema / anaphylaxis: Swelling of the airway requiring medical — not behavioral — management

• Breathing pattern disorder: Dysfunctional breathing mechanics without laryngeal obstruction

• Awake laryngospasm: Sudden glottic closure, often linked to reflux; resolves in under 30 seconds

• Extrathoracic obstruction: Structural narrowing of the upper airway that rules out a functional ILO diagnosis

• Panic attack: In ILO, panic follows breathing distress — not the reverse

Why accurate differential diagnosis is the treatment

This is perhaps the most important clinical insight we can share: when a patient has both ILO and asthma, they need to learn to tell the difference between an asthma attack and an ILO event — because the correct response is completely different. For ILO, behavioral breathing recovery strategies are the answer. For asthma, that means a rescue inhaler. Using the wrong approach for the wrong condition not only fails to help — it can delay the right intervention at a critical moment.

Similarly, conditions like respiratory laryngeal dystonia look very similar to ILO but do not respond to behavioral therapy at all. Pursuing respiratory retraining in a patient with dystonia means months of effort with no benefit — while the underlying neurological condition goes unaddressed.

What this means for your care

If you or your child has been diagnosed with ILO, or if you're still searching for answers after years of breathing difficulties, a comprehensive assessment by a speech-language pathologist experienced in upper airway disorders is an essential step. Our role isn't just to teach breathing techniques. It's to make sure we understand your unique clinical picture well enough that those techniques are exactly right for you.

We work closely with pulmonologists, allergists, ENTs, and primary care providers to ensure that when multiple conditions are present, each one has a clear treatment plan and that you understand when to use which strategy.

You've likely been through a lot before reaching this point. We take that seriously. Our goal is to give you confidence — in your diagnosis, in your treatment, and in your ability to manage your breathing.

Reach out today for a comprehensive assessment and treatment plan.

Reference: Sandage M., Milstein C., and Nauman E. Inducible Laryngeal Obstruction Differential Diagnosis in Adolescents and Adults: A Tutorial. American Journal of Speech-Language Pathology, Volume 32, Issue 1, Jan 2023.

Disclaimer: This blog post is for informational purposes only and should not be considered a substitute for professional medical advice. Please consult with a qualified speech pathologist for a personalized evaluation and treatment plan.