What is Exercise-Induced Laryngeal Obstruction?
Inducible laryngeal obstruction (ILO) is a condition that results in narrowing or improper blocking of the true vocal fold or the structures situated above our windpipe in response to certain triggers or stimuli. If it occurs while exercising, it’s known as exercise-induced laryngeal obstruction (EILO). The term ILO was introduced recently, around 2013, to denote “inducible obstructions in the larynx that cause difficulty in breathing.” This term was first proposed by major medical associations including the European Respiratory Society, the European Laryngological Society, and the American College of Chest Physicians. This replaced older terms like vocal cord dysfunction (VCD) or paradoxical vocal fold motion (PVFM) that were popularly used to describe this illness. Unlike VCD and PVFM, the term ILO is more explanatory as it also accounts for illnesses affecting the supraglottic structures, not just the vocal folds.
This condition was first noticed in 1869 by Sir Morrell Mac-Kenzie. For a long time, it was considered to be primarily psychological in origin, as mentioned later in the New England Journal of Medicine. Throughout history, many different names have been used to describe this condition in medical literature. Some of the older names for this disorder include Munchausen stridor, functional laryngeal obstruction, emotional laryngeal wheezing, irritable larynx syndrome, and factitious asthma, among others.
What Causes Exercise-Induced Laryngeal Obstruction?
Throughout the years, many things have been identified as causing laryngeal obstruction, also known as VCD. These causes can include smells, acid reflux, exercise, irritants, and anxiety. Morris has grouped these triggers into three main categories: psychogenic, irritant-induced, and exertional.
Psychogenic refers to causes related to mental or emotional processes, irritant-induced means it’s triggered by something that bothers the throat, like smoke or dust, and exertional refers to causes related to physical activity.
This explanation will mainly discuss exercise-induced laryngeal obstruction, as it is a common issue doctors often come across.
Risk Factors and Frequency for Exercise-Induced Laryngeal Obstruction
Exercise-induced laryngeal obstruction, or EILO, is a condition that’s often found in young people, particularly between adolescence and early adulthood. Studies have found that it affects about 5% to 10% of people in this age group. According to research involving 112 young people with EILO, symptoms tend to start at around 13.8 years old, with an average diagnosis age of 15.4 years. There’s also evidence that EILO is more prevalent in females, with one study finding that around 81.3% of their 112 EILO patients were female. This condition is most common in young athletes, especially females, and can even affect those who compete at an elite level.
- EILO is common in adolescents and young adults, with a prevalence of 5-10%.
- The onset of EILO symptoms typically occurs at 13.8 years.
- The average age of EILO diagnosis is 15.4 years.
- EILO is more prevalent among females, with one study finding that 81.3% of EILO patients were female.
- The condition is commonly found in adolescent athletes and can impact those performing at a high level of competition.
Signs and Symptoms of Exercise-Induced Laryngeal Obstruction
Exercise-induced laryngeal obstruction (EILO) can cause a variety of symptoms. These might include breathlessness, high-pitched breathing, wheezing, change in voice, tightness in the throat or chest, and feeling anxious. Breathlessness and high-pitched breathing are particularly common, being reported by almost all patients in several large studies.
People may not always recognize the high-pitched breathing and may simply describe it as “breathing noisily”. Usually, these symptoms appear during vigorous physical activity. Unlike exercise-induced bronchospasm (a kind of asthma), which tends to occur after exercise, the symptoms of EILO are generally felt when breathing in during peak exercise, and they usually go away within a few minutes.
It’s also important to note that relievers used for asthma-like symptoms aren’t typically effective for EILO. It’s often found in teenage girls who play sports, and typically they don’t have many symptoms when not exercising. Sufferers of EILO may have had many previous tests or treatments for exercise-induced asthma, as EILO is not often recognized as a cause of breathlessness induced by exercise.
The diagnosis of EILO is challenging, because typically patients only have symptoms during exercise and appear perfectly normal at rest. The presence of wheezing or high-pitched breathing while at rest might suggest other issues with the airway that need further medical evaluation.
Testing for Exercise-Induced Laryngeal Obstruction
When it comes to diagnosing exercise-induced laryngeal obstruction (EILO), your doctor will typically rely on your symptoms, especially if no other breathing or airway disorders are present.
Medical imaging won’t be used to diagnose EILO, but it can help rule out other lung and airway disorders if suspected.
A common test called spirometry might be used. This measures how well your lungs function, though it’s not considered a tool for diagnosing EILO. Patients with EILO typically have normal results on this test. On occasion, the airflow patterns shown on the test may be suggestive of EILO. However, such patterns aren’t usually seen in this condition.
The most reliable way to diagnose EILO is through the use of flexible laryngoscopy during symptomatic periods. This test involves the use of a thin flexible tube with a camera on the end (a laryngoscope) that is passed through the nose to visualize the larynx (voice box). This is typically performed by a specialist like an ear, nose, and throat doctor, a lung specialist, or a speech therapist during a period of exercise. The idea is to provoke and capture the symptoms that are usually absent when you’re at rest.
Lately, an updated laryngoscopy method, Continuous Laryngoscopy during Exercise (CLE), allows doctors to continuously monitor the voice box throughout the exercise. This method requires a unique setup that might not be available everywhere. It involves attaching the laryngoscope to the head via a band or helmet. This way, the doctor can get a real-time view of the larynx throughout the exercise. In this procedure, heart and lung data are also collected as the patient exercises.
Typical EILO signs, like the narrowing of the vocal cords, may be detected during these procedures.
Among the medical community, CLE is increasingly being recognized as the preferred testing method for diagnosing EILO.
Treatment Options for Exercise-Induced Laryngeal Obstruction
Managing exercise-induced laryngeal obstruction, which is when your throat narrows or closes during high-level physical activity, typically involves a team of different medical professionals. This team often includes ear, nose, and throat doctors (otolaryngologists), lung specialists (pulmonologists), speech pathologists who are experts in swallowing and voice disorders, and psychologists.
Usually, the first step in managing this condition involves seeing a speech pathologist for a treatment method known as respiratory retraining therapy. This treatment involves the learning of special breathing techniques that can help to keep the throat open during exercise. Alongside these techniques, therapy may also include behavioral therapy, reassurance, learning about how our respiratory system works (respiratory mechanics), and sometimes biofeedback, which is a process of gaining greater awareness of many bodily functions with the goal of manipulating them at will.
In cases where the above treatments do not work, a surgical procedure called supraglottoplasty may be considered. This is mainly applied when the structures at the back of the mouth and throat, above the vocal cords (supraglottic) are involved.
Medications to open the airways (bronchodilators) or other inhaled therapies usually don’t have a role in treating exercise-induced laryngeal obstruction. However, these therapies can be beneficial if the patient is suffering from asthma as well.
What else can Exercise-Induced Laryngeal Obstruction be?
As mentioned earlier, a condition similar to exercise-induced bronchospasm (or EIB) is the primary competing diagnosis to consider. This condition typically results in symptoms such as difficulty exhaling, which usually happens later during physical activity and gets better with bronchodilators — medicines that help to open up the airways. EIB is often characterized by a whistling sound while breathing out, known as expiratory wheezing.
Certain heart conditions, as well as anxiety attacks, can also cause sensations of tightness in the chest and difficulty in breathing.
Additionally, abnormal physical structures in the larynx (voice box) and trachea (windpipe) could be responsible for the symptoms. This can include a narrowed area below the voice box (subglottic stenosis), pressure on the larynx or trachea due to a mass, or a ring or sling in the trachea.
What to expect with Exercise-Induced Laryngeal Obstruction
In general, it’s widely believed, based on available research, that exercise-induced laryngeal obstruction (a condition where the voice box narrows during exercise) resolves on its own over time. Most patients improve with speech therapy, which involves exercises to control voice and breathing.
However, in stubborn cases, especially when the problem is suspected to be located in the supraglottic region (the upper part of the voice box), a medical procedure called supraglottoplasty is usually effective. This procedure reshapes the upper part of the voice box to help improve airflow and reduce symptoms.
Possible Complications When Diagnosed with Exercise-Induced Laryngeal Obstruction
While there are usually no severe issues associated with exercise-induced laryngeal obstruction, it’s important to seek assistance from a medical professional for proper treatment. If not appropriately addressed, this condition may decrease the affected person’s capability to take part in sports activities or any physical exertions that might worsen the obstructive nature of the larynx.
Key Points:
- Usually there are no severe problems associated with exercise-induced laryngeal obstruction
- Need for medical assistance for optimal management
- Not receiving the right treatment can limit the person’s ability to engage in physical activities that trigger the condition
Preventing Exercise-Induced Laryngeal Obstruction
Exercise-induced laryngeal obstruction (EILO) is a condition often seen in teenagers and young adults during physical activity. It occurs when there is a narrowing in the upper airway and the area around the vocal cords while taking a breath in. Symptoms may include noisy breathing, feeling short of breath, tightness in the chest, and coughing.
Your doctor will likely first check for other possible causes of your symptoms, such as asthma, acid reflux, or other upper airway problems.
If EILO is diagnosed, your doctor may recommend that you see a speech therapist. The therapist can teach you specific breathing techniques that can help prevent the symptoms of EILO from occurring.
