What causes eilo

What is Exercise-Induced Laryngeal Obstruction (EILO)?

Exercise-Induced Laryngeal Obstruction, commonly abbreviated as EILO, is a condition that affects the upper airway, specifically the larynx (voice box). It is characterized by the abnormal movement of the vocal cords and surrounding laryngeal structures during physical exertion. Instead of the vocal cords opening wider to allow maximum airflow into the lungs, they may flutter, collapse inwards, or constrict during inhalation, leading to a feeling of breathlessness and difficulty breathing.

What Causes EILO?

The precise cause of EILO is not fully understood, but it is believed to involve a combination of factors related to the complex mechanics of breathing during intense exercise. Several theories exist:

1. Abnormal Laryngeal Reflexes:

One primary theory suggests that EILO is due to an exaggerated or abnormal reflex response within the larynx. During strenuous exercise, the body requires a significant increase in airflow. In individuals with EILO, the laryngeal muscles may overreact to the increased respiratory demand, causing them to contract or move abnormally, thus obstructing airflow.

2. Anatomical Factors:

While not always present, certain anatomical variations in the larynx might predispose individuals to EILO. These could include a predisposition for the arytenoid cartilages (part of the larynx) to move anteriorly (forward) during inhalation, or a narrower than usual laryngeal opening.

3. Triggers and Contributing Factors:

Several factors can trigger or exacerbate EILO symptoms in susceptible individuals:

• High-Intensity Exercise: The rapid and deep breathing required during intense aerobic activities is a major trigger.
• Environmental Factors: Cold, dry air, or air containing irritants like pollution or allergens can sometimes worsen laryngeal sensitivity and contribute to obstruction.
• Gastroesophageal Reflux Disease (GERD): Some studies suggest a link between GERD and EILO. Stomach acid refluxing into the esophagus can irritate the larynx, potentially making it more prone to abnormal movements during exercise.
• Allergies: Laryngeal hypersensitivity due to allergies might also play a role in some cases.
• Learned Breathing Patterns: In some instances, individuals may develop abnormal breathing patterns during exercise, which can contribute to the development or persistence of EILO.

Symptoms of EILO

The hallmark symptom of EILO is a sudden onset of shortness of breath or difficulty breathing that occurs specifically during or immediately after strenuous physical activity. This breathlessness is often accompanied by:

• A feeling of throat tightness or constriction.
• Audible stridor (a high-pitched, noisy sound during breathing), particularly during inhalation.
• Coughing.
• A feeling of needing to stop exercising.

Crucially, these symptoms typically resolve quickly once the exercise stops and normal breathing is resumed. This rapid resolution is a key differentiator from conditions like asthma, where symptoms may linger.

Diagnosis of EILO

Diagnosing EILO can be challenging as symptoms are intermittent and related to exercise. A thorough medical history and physical examination are the first steps. The definitive diagnosis is usually made through a procedure called laryngoscopy performed *during* exercise. This involves a doctor inserting a small, flexible camera (endoscope) into the nose or mouth to visualize the larynx while the patient is exercising, often on a treadmill or stationary bike. This allows direct observation of any abnormal vocal cord or laryngeal tissue movement.

Treatment and Management

Treatment for EILO is tailored to the individual and the severity of their condition. Common approaches include:

• Speech and Language Therapy: This is often the first line of treatment. Therapists teach specific breathing techniques, exercises to improve laryngeal control, and strategies to manage the feeling of breathlessness.
• Nasal Breathing Techniques: Encouraging nasal breathing during exercise can help humidify and warm the air before it reaches the larynx, potentially reducing irritation.
• Addressing Underlying Conditions: If GERD or allergies are contributing factors, treating these conditions may alleviate EILO symptoms.
• Pharmacological Management: In some cases, medications like nasal steroids or proton pump inhibitors (for GERD) might be prescribed.
• Surgical Intervention: For severe cases unresponsive to conservative treatments, surgery may be considered to widen the airway or remove tissue that obstructs airflow.

EILO is a condition that requires careful diagnosis and management by healthcare professionals, particularly those specializing in sports medicine or otolaryngology (ear, nose, and throat specialists).