About this rare condition
What is idiopathic subglottic stenosis?
Understanding the medical terms
Idiopathic subglottic stenosis (ISGS) is a narrowing of the windpipe (trachea) just below the vocal cords. This narrowing is caused by scar tissue.
- Idiopathic: without a known cause.
- Subglottic: the area just below the vocal cords (glottis). This part connects the voice box (larynx) to the windpipe.
- Stenosis: a medical term for narrowing.
Doctors sometimes use the terms ‘airway stenosis’ or ‘laryngotracheal stenosis’. Larynx is the medical word for the voice box.
Different types of tracheal stenosis
There are four types of tracheal stenosis. The symptoms are often similar, but the causes are different. To diagnose ISGS, your doctor first rules out the other three types.
Idiopathic stenosis
There is no known cause.
Autoimmune-related stenosis
This type of stenosis can occur with conditions such as GPA, vasculitis, RPC, SLE, rheumatoid arthritis (RA), sarcoidosis, amyloidosis, or IgG4-related disease.
Stenosis caused by trauma
Injury to the windpipe, for example by hot air, radiation or an accident.
Iatrogenic stenosis
Caused by medical treatment, such as long-term intubation or a tracheotomy.
Symptoms usually start within two years.
Symptoms of ISGS
People with idiopathic subglottic stenosis (ISGS) often experience a range of symptoms. The most common ones are:
Stridor
- A high-pitched, noisy sound when breathing, caused by narrowing in the airway.
- It is often worse during exercise or stress.
- If the narrowing worsens, the noisy breathing may become constant.
- Some patients may not notice it themselves, but others might hear it.
Coughing
There are two types of cough linked to ISGS::
Cough caused by irritation
This occurs when the lining of the airway becomes irritated, for example, due to an infection, inflammation, or allergies.
Coughing spells can be long-lasting, exhausting, and interfere with daily activities.Coughing to clear mucus
At the site of the stenosis, cilia (tiny hairs in the airway) are absent. As a result, mucus builds up in the windpipe and needs to be coughed up.
Normally, cilia move mucus upward without you noticing. In ISGS, the absence of cilia at the narrowing means the mucus must be cleared by coughing. This can worsen with exercise, talking a lot, or stress.
Shortness of breath
Breathing, speaking, laughing or singing becomes more difficult. The symptoms can look like asthma, which can delay the diagnosis.
Mucus build-up
People with ISGS do not produce more mucus than healthy individuals. But the narrowing causes mucus to collect and dry out. This can lead to infections. Sometimes a thick “mucus plug” comes loose.
Inflammation
Frequent coughing can irritate the mucosa and cause inflammation. This may create a vicious circle. A short course of (inhaled) steroids can sometimes help.
Treatments
You can find more information and a short video that explains what a dilation is on our Treatment options page.
Who gets ISGS?
ISGS is very rare: about 0.2 per 100,000 people are diagnosed each year.
98 to 100% of patients are women.
The condition usually develops between the ages of 20 and 50.
ISGS occurs more often in people of European (Caucasian) descent.
ISGS is not or rarely hereditary.
Less than 3 percent of patients have a family member with ISGS.
The cause is unknown. Autoimmune or hormonal factors may play a role, but this has not been proven.
The disease is often mistaken for asthma, bronchitis or Vocal Cord Dysfunction (VCD).
Summary
Idiopathic subglottic stenosis is a rare condition in which scar tissue causes a narrowing of the windpipe. This can lead to breathing problems, coughing and mucus complaints. The cause is unknown. Because the symptoms resemble other conditions, the diagnosis is often delayed.
There are different treatment options available, depending on the severity of the narrowing and the patient’s situation.