ILO causes, triggers and management

Causes of Inducible Laryngeal Obstruction

The precise cause of ILO is unclear. However, it is generally thought that ILO occurs because the throat becomes hypersensitive to a combination of different triggers, including physical, psychological or environmental factors.
 
Your throat is reacting to these triggers by closing the airway to protect the lungs from these irritants, affecting your ability to breathe.

It is important to explore and understand what may trigger ILO in you. If you are able to identify the underlying triggers, you can manage these to reduce the number of ILO episodes you may experience. This can improve your quality of life.

ILO can occur due to multiple triggers, including:
1.    External environmental triggers
2.    Physical triggers
3.    Emotional triggers

Common ILO triggers are, as follows:

Environmental triggers:

1.   Inhaled irritants:

Smoke, strong odours, perfumes, chemicals and other air pollutants can trigger ILO, as these can irritate or cause inflammation of the linings of your throat and voice box. This can trigger protective reflexes that lead to vocal cord closure.

2.    Allergens:

Allergens (substances that can cause an allergic reaction) such as pollen, dust, pet hair or certain foods, can cause allergic reactions that lead to irritation and inflammation of the airway. Allergens can also cause the body to produce more mucous which can lead to coughing and throat clearing. These types of irritation can make your voice box and vocal cords more sensitive, leading to ILO symptoms.

By understanding how irritants and allergens can trigger ILO and taking steps to manage exposure, you can reduce the frequency and severity of ILO episodes and improve your quality of life.

Physiological factors:

1.    Nerve control: ILO can occur due to problems with how the nerves control the muscle in the throat. If there are problems with the nerve signals to the muscles of your throat or vocal cords, the vocal cords can close when they should stay open.

2.    Muscle dysfunction: the muscles that move the vocal cords need to work well to keep the vocal cords moving efficiently. If the muscles in the throat are tight, strained, overused or injured they may not work as well as they should. Muscle tension can restrict the movement of the muscles in your throat, leading to inappropriate closure of the vocal cords, as well as make it more difficult to open up the airway and improve breathing during ILO.

Emotional triggers:

1.    Stress and Anxiety: these can be significant contributors to ILO. Stressful situations can trigger hyperventilation and increased laryngeal muscle tension, which can lead to symptoms of ILO.
2.    Behavioural: specific behaviours such as throat clearing, coughing, voice misuse, laughing or shouting can trigger ILO symptoms, as these behaviours can irritate the vocal cords.

Medical conditions:

1.    Gastroesophageal Reflux Disease (GORD): GORD can be common in people who experience ILO. This can cause inflammation or irritation of the larynx and vocal cords. (link to acid reflux information)
2.    Asthma: Although ILO is distinct from asthma, it can coexist with asthma and other respiratory conditions. Chronic inflammation can contribute to the development of ILO.

Exercise:

1.    Intense physical exertion can induce ILO. This is specifically known as Exercise Induced Laryngeal Obstruction (EILO). This happens because increased respiratory demands can lead to increased muscle activity in our larynx or voice box.

Sometimes there are no apparent causes for ILO symptoms. However, treatment of the symptoms can still be effective.

How is ILO diagnosed?

ILO is diagnosed by a specialist multidisciplinary team consisting of ENT and Respiratory Medicine. Specialist assessment is carried out so that you are provided with an appropriate and correct diagnosis.

As ILO can exist separately or co-exist with other respiratory conditions, diagnosis and treatment can be challenging. Therefore, it is important that you undergo specialist assessment to diagnoses and manage this condition effectively.

Management of ILO

Effective management of ILO requires a comprehensive individualised treatment approach that addresses the conditions underlying causes and helps to alleviate your symptoms. If you do not have a diagnosis of ILO but are suffering from the aforementioned symptoms, it is important that you seek advice from ENT and Respiratory medicine.

You will receive advice from ENT, Respiratory medicine and Speech and Language Therapy. The following information will provide guidance on particular areas to focus on.
 
This ILO resource toolkit looks to provide information and advice to help you better understand ILO and enable you to manage the symptoms that you may be experiencing.

Only proceed with the following advice and exercises if you have been reviewed by ENT or Respiratory medicine and you have been advised to carry these out.

The following advice and exercises will require consistent practice and perseverance to achieve results.

Please consider the following areas to help you identify and manage ILO symptoms.

1.    Identify triggers

A key aspect of managing ILO is learning, identifying and avoiding known triggers.

Identifying triggers will help you control, manage and reduce symptoms of ILO. Avoiding known irritants and allergens can significantly reduce the occurrence of ILO episodes. Understanding your condition will help you feel more in control and less anxious about your symptoms.

Useful points to consider when identifying ILO triggers:

•    Keep a diary of ILO episodes. Think about what you have been doing immediately before or during an ILO episode or where you have been. Record this detail to determine whether there are any trigger patterns identified.

2.    Identify early signs of ILO

Identify Early Warning Signs that an ILO episode is starting.
These might include:

• Feeling of irritation or tightness in your throat
• Sensation of your throat closing up
• Difficulty breathing or feeling short of breath
• Hoarseness or changes in your voice
• Coughing or throat clearing

If you experience any of these symptoms, they may remind you to start rescue breathing exercises . These could help to prevent or shorten an ILO episode.

3.    Throat care:

It is important to ensure that your throat remains as healthy as possible when managing symptoms of ILO. Throat care can help to prevent irritation, reduce inflammation, improve vocal cord function, minimize triggers for ILO, support breathing techniques and help improve recovery following an ILO episode. When your throat is healthy, it is easier to practice and maintain breathing techniques that are important for managing ILO. It will also allow the throat to recover more quickly.

Please consider aspects of throat care that you might be able to change to help you manage ILO symptoms. Read information on throat care.

4.    Reduce muscle tension

Muscle tension can contribute to ILO. It can be difficult to control ILO if the muscles of your throat and neck are tight. Muscle tension can also encourage the vocal cords to close when they should stay open for breathing, as it restricts muscle movement. If your muscles stay tense, it can prolong or worsen the symptoms of an ILO episode.

Relaxing the muscles of your throat, jaw and neck is key to helping the vocal cords open back up and allow you to breathe normally. Managing muscle tension through relaxation techniques and breathing exercises is important to control ILO symptoms.

You can relax your throat, jaw and neck by carrying out the following exercises:

• Carry out relaxation exercises for the throat, jaw, tongue and neck (link to deconstriction exercises)
• Further jaw, throat and neck stretching exercises can be found on our  voice warm up exercises and video page.

5.    Rescue breathing strategies:

Rescue breathing is a useful technique to manage ILO and can reduce the severity and length of ILO episodes.

These techniques help to promote relaxation of the muscles in your throat and voice box and encourage your vocal cords to move back into an open position during an ILO episode. This allows air to flow more easily through your upper airway and will help you to breathe more easily.

ILO episodes can be frightening which can make you feel anxious or panic. Rescue breathing techniques focus on controlled, steady and calm breathing. This helps to reduce anxiety and muscle tension and helps to reduce or prevent the vocal cords from tightening further. It also helps to normalise breathing patterns and give the vocal cords a chance to relax.

Regular practise of rescue breaths, even when you have no symptoms, can train your body to respond better during an ILO episode. You will become familiar with this technique, so that you can use it more easily when you are experiencing episodes of ILO.
Rescue breathing exercises can be found here.

Further information can be found by reading the Royal College of Speech and Language Therapists Upper airway disorders factsheet.