Subglottic Stenosis: Symptoms, Types, Causes and Treatment

Subglottic stenosis (SGS) is a serious medical condition characterized by narrowing of the airway just below the vocal cords. This narrowing can lead to a range of respiratory symptoms, impact quality of life, and require complex management strategies. Understanding the symptoms, types, causes, and treatment options for subglottic stenosis is crucial for patients, caregivers, and healthcare professionals alike.

Symptoms of Subglottic Stenosis

Recognizing the symptoms of subglottic stenosis can be challenging, as they often mimic more common respiratory conditions. Early identification is vital for effective management and prevention of complications.

Symptom	Description	Severity Range	Source(s)
Stridor	High-pitched, noisy breathing	Mild to severe	2 4 6
Dyspnea	Shortness of breath, especially on exertion	Mild to severe	1 2 4 6
Cough	Persistent or recurrent	Mild	1 2 6
Voice Changes	Hoarseness, weak or altered voice	Mild	2 4 6
Recurrent Croup	Frequent croup episodes in children	Mild to moderate	2 4
Complete Obstruction	Life-threatening airway blockage	Severe	2 4

Table 1: Key Symptoms

Understanding the Symptoms

Stridor

Stridor is a hallmark sign of subglottic stenosis, characterized by a harsh, high-pitched sound when breathing in. It often becomes more pronounced during physical activity or respiratory infections. In infants and children, recurrent or persistent stridor should prompt evaluation for airway narrowing 2 4.

Dyspnea (Shortness of Breath)

Patients frequently report difficulty breathing, which may initially occur only during exertion but can progress to problems at rest. As the airway becomes more constricted, even mild activity or talking can trigger breathlessness 1 2 4.

Cough and Sputum

A chronic cough, sometimes accompanied by mucus, is common. This can be mistaken for asthma, bronchitis, or other respiratory illnesses, leading to delayed diagnosis 1 2 6.

Voice Changes

Some individuals develop a weak, hoarse, or altered voice due to restricted airflow or involvement of the vocal cords. This is especially evident in more advanced cases 2 4 6.

Recurrent Croup (in Children)

Children with subglottic stenosis may experience frequent episodes of croup—a barking cough and stridor—often not responding to standard treatments. This can be a key clue to underlying airway narrowing 2 4.

Complete Obstruction

In severe cases, the airway can become critically narrowed, leading to respiratory distress or even life-threatening obstruction. This requires immediate medical attention and intervention 2 4.

Types of Subglottic Stenosis

Subglottic stenosis is not a single disease but a group of disorders classified by cause and pattern. Understanding the different types helps guide diagnosis and treatment.

Type	Defining Feature	Typical Age Group	Source(s)
Congenital	Present at birth; developmental anomaly	Infants/Children	2 4 8
Acquired	Develops after birth due to injury or disease	All ages	2 4 8 10
Idiopathic	No identifiable cause	Adults (mostly women)	3 5 6 9
Autoimmune	Associated with diseases like GPA	Adults	6 9 11
Traumatic	Due to external or internal trauma	All ages	9

Table 2: Types of Subglottic Stenosis

A Closer Look at Types

Congenital SGS

Congenital subglottic stenosis is present at birth and results from abnormal development of the airway. It is rare and most commonly identified in infants or young children with persistent noisy breathing or recurrent croup 2 4 8.

Acquired SGS

Acquired forms develop after birth. The most common cause is prolonged intubation, especially in premature infants or critically ill adults. Other causes include trauma, infection, or previous surgery in the airway 2 4 8 10.

Idiopathic Subglottic Stenosis (iSGS)

Idiopathic SGS occurs when no cause can be determined, even after thorough evaluation. This form predominantly affects middle-aged women and is characterized by progressive airway narrowing and repeated need for intervention 3 5 6 9. The pathophysiology involves chronic inflammation and fibrosis, but the exact trigger remains unclear 5 8.

Autoimmune-Related SGS

Autoimmune diseases, such as granulomatosis with polyangiitis (GPA), can cause inflammation and scarring of the subglottic region, leading to stenosis. Diagnosis often requires specific laboratory testing and imaging to distinguish from idiopathic forms 6 9 11.

Traumatic SGS

This rare type results from direct injury to the airway, such as blunt neck trauma or surgical complications 9.

Causes of Subglottic Stenosis

Understanding the underlying causes of subglottic stenosis is essential for prevention and tailored treatment. Causes may be multifactorial and differ by age group.

Cause	Mechanism	Risk Factor Example	Source(s)
Prolonged Intubation	Injury from breathing tube	Premature infant, ICU patient	4 8 10
Idiopathic	Unknown (possible immune/fibrotic)	Middle-aged women	5 6 8 9
Autoimmune	Systemic inflammation	Granulomatosis with polyangiitis	6 9 11
Congenital	Developmental anomaly	Birth defect	2 4 8
Infection	Post-infectious scarring	Severe airway infection	4
Trauma	Direct airway injury	Neck injury, surgery	9

Table 3: Causes of Subglottic Stenosis

Diving Deeper into Causes

Prolonged Intubation

The leading cause of acquired SGS is injury from prolonged placement of a breathing tube (endotracheal or tracheostomy tube). This can cause local inflammation, ulceration, and ultimately scarring (fibrosis) of the airway. The introduction of neonatal intensive care and life-saving ventilation has increased the prevalence of post-intubation SGS, especially in premature infants 4 8 10.

• Pathogenesis: Intubation changes the local tissue environment, causing hypoxia, inflammation, and abnormal wound healing. This leads to excess scar tissue and narrowing 10.

Idiopathic Causes

Idiopathic SGS is defined by the absence of identifiable risk factors or underlying disease. Most patients are middle-aged women, and research implicates chronic, localized inflammation and abnormal fibroblast activity. The inflammatory IL-17A/IL-23 axis and immune checkpoint pathways (PD-1/PD-L1) have been identified as possible mechanisms 5 6 8.

Autoimmune Disorders

Autoimmune diseases, notably granulomatosis with polyangiitis (formerly Wegener’s), can cause recurrent inflammation and fibrosis of the subglottic region. These cases may be difficult to distinguish from idiopathic SGS without specific laboratory and pathological findings 6 9 11.

Congenital Anomalies

Congenital SGS results from abnormal development of the airway, often with a thickened cricoid cartilage or incomplete airway formation. Unlike acquired forms, congenital SGS may improve with time, although some cases require surgical intervention 2 4 8.

Infection and Trauma

Severe airway infections, including bacterial tracheitis, or direct trauma to the airway can lead to post-inflammatory or post-traumatic stenosis. Surgical injury during airway procedures is another known cause 4 9.

Treatment of Subglottic Stenosis

Treatment strategies for subglottic stenosis depend on severity, underlying cause, and patient preferences. Advances in surgical techniques and adjunct therapies are improving outcomes, but recurrence remains a challenge.

Treatment	Approach	Typical Use Case	Source(s)
Endoscopic Procedures	Minimally invasive	Mild-moderate stenosis, patient preference	3 11 12 15
Open Surgery	Tracheal resection/reconstruction	Severe stenosis, failed endoscopic	3 7 13
Medical Therapy	Steroids, immunosuppressants	Adjunct or specific cases (e.g., autoimmune)	6 11 14
Stenting	Airway support	Temporary measure or bridge	1 13
Tracheotomy	Bypass obstruction	Emergency, severe cases	2 4 13
Office-based Injections	Serial steroid injections	Mild iSGS, delay surgery	14

Table 4: Treatment Approaches

Exploring Treatment Options

Endoscopic Procedures

Endoscopic management is the first-line treatment for many patients due to its minimally invasive nature. Techniques include balloon dilation, laser or cold knife incisions, and adjunctive use of medications like mitomycin or steroids to slow scar formation 3 11 12 15.

• Benefits: Voice preservation, lower risk, shorter recovery.
• Limitations: High recurrence rates—many patients require repeated procedures 3 11.

Open Surgical Resection

Open laryngotracheal resection or reconstruction is considered the definitive treatment for severe or recurrent cases, particularly idiopathic SGS. It involves removing the scarred segment and joining healthy airway ends 3 7 13.

• Benefits: High cure rates, low long-term recurrence.
• Risks: Invasive, requires external incision, longer recovery, potential voice changes.

Medical Therapy

Steroids (systemic or local injection) and immunosuppressants are used as adjuncts, especially in autoimmune SGS. Recent interest in serial office-based steroid injections offers a non-surgical option for mild idiopathic SGS, potentially delaying or reducing the need for surgery 6 11 14.

Airway Stenting

Devices like the Montgomery T-tube can temporarily maintain airway patency. Stents are typically used as a bridge to surgery or in patients not fit for definitive intervention 1 13.

Tracheotomy

In emergency or very severe cases, a tracheostomy creates a direct airway through the neck below the obstruction. The goal is usually to stabilize the patient before more definitive treatment 2 4 13.

Patient Preferences and Emerging Therapies

Studies show patients prioritize voice quality, low risk, and procedure frequency over factors like incision or hospital stay. Most prefer endoscopic approaches, even if multiple treatments are required 15. Ongoing research into immunomodulatory therapy and in-office interventions continues to evolve the landscape of SGS management 8 14.

Conclusion

Subglottic stenosis is a complex and potentially life-threatening condition with diverse causes, presentations, and management strategies. Early recognition and a multidisciplinary approach are critical for optimal outcomes.

Key takeaways from this article:

• Symptoms: Stridor, dyspnea, cough, voice changes, and recurrent croup are common signs. Severe cases may cause complete airway obstruction.
• Types: SGS is classified as congenital, acquired, idiopathic, autoimmune, or traumatic—each with unique features and implications.
• Causes: The condition arises from prolonged intubation, autoimmune disease, congenital anomalies, idiopathic mechanisms, infection, or trauma.
• Treatment: Options include endoscopic procedures, open surgery, medical therapy, airway stenting, and tracheotomy. Patient preferences and disease severity guide management choices.

Understanding subglottic stenosis equips patients, families, and clinicians to recognize symptoms early, pursue accurate diagnosis, and choose the most effective treatments for this challenging airway disorder.