Laryngomalacia: Symptoms, Types, Causes and Treatment

Laryngomalacia is the most common cause of noisy breathing (stridor) in infants. While often self-limited, its symptoms and potential complications can be deeply distressing for both children and their caregivers. Understanding its symptoms, types, underlying causes, and available treatments is crucial for early recognition and effective management. This comprehensive article explores the current knowledge on laryngomalacia, synthesizing evidence from clinical studies and expert consensus.

Symptoms of Laryngomalacia

Laryngomalacia’s symptoms are often the first clue for both parents and clinicians. While the hallmark is stridor—a distinct high-pitched, musical sound during inhalation—other symptoms can range from mild to severe, sometimes threatening a child’s health and development.

Symptom	Description	Severity Spectrum	Source(s)
Stridor	High-pitched, inspiratory noise	Mild to severe	2 3 4 5
Retractions	Indrawing of chest above/below sternum	Indicator of severity	1 3 4
Feeding Issues	Difficulty feeding, choking, vomiting	Mild to severe	1 3 4 5
Cyanosis	Bluish skin, especially with feeding	Severe	4 5
Failure to Thrive	Poor weight gain or growth	Severe	3 4 5
Apnea	Pauses in breathing	Severe	4
Sleep Problems	Snoring, sleep-disordered breathing	Mild to moderate	2 3

Table 1: Key Symptoms and Severity Indicators

Understanding the Symptoms

Stridor is the central symptom, typically appearing within the first days or weeks of life. It sounds musical and is most pronounced when the baby is feeding, excited, or lying on their back. The stridor is caused by the soft tissue above the vocal cords collapsing inward during inhalation, partially blocking the airway 3 5.

Signs of Severity

While most cases are mild, about 10-20% of infants may develop severe symptoms. Indicators include:

• Persistent or worsening stridor
• Intercostal or substernal retractions (chest wall indrawing)
• Feeding difficulties that may include choking, gagging, or recurrent vomiting
• Cyanosis, especially during feeds or crying
• Failure to thrive (poor weight gain)
• Apnea or oxygen desaturation episodes 1 3 4 5

These severe symptoms often indicate significant airway compromise and require prompt medical evaluation.

Associated Symptoms

Some infants also experience sleep-related breathing disorders, such as snoring or obstructive sleep apnea. Feeding issues are not only distressing but can lead to weight loss or growth delays. In the most severe cases, these symptoms may warrant surgical intervention 1 4 5.

Types of Laryngomalacia

Laryngomalacia encompasses a range of anatomical and functional variants. Understanding the subtypes helps guide diagnosis and tailor treatment.

Type	Key Features	Clinical Notes	Source(s)
Type I	Short/tight aryepiglottic folds	Most common in infants	7 8 9
Type II	Redundant supraglottic soft tissue	Associated with comorbidities	7 8
Type III	Other etiologies (e.g., neuromuscular)	Often severe, older children	6 7 8
Combined Types	Features of multiple types	Increased risk of other airway malacia	8

Table 2: Main Types of Laryngomalacia

Classification Systems

Multiple classification systems exist, but none is universally accepted 9. Most systems categorize laryngomalacia based on:

• The anatomical site and nature of supraglottic collapse (e.g., aryepiglottic folds, epiglottis, arytenoid mucosa)
• The presence of redundant tissue
• Underlying pathophysiological mechanisms, such as neuromuscular dysfunction 7 9

Type I: Aryepiglottic Fold Shortening

This type is characterized by tight or foreshortened aryepiglottic folds that pull the epiglottis inward, leading to airway narrowing during inspiration. It is the most frequent form seen in early infancy 7 8.

Type II: Redundant Supraglottic Tissue

Here, excessive floppy soft tissue in the supraglottic area collapses into the airway. This type is often associated with other airway or systemic comorbidities and may present in older infants or children 6 7 8.

Type III: Neuromuscular or Other Etiologies

Type III laryngomalacia includes cases where the collapse is due to neuromuscular weakness or other less common causes. These cases can be more severe and are sometimes seen in older children or those with underlying neurological disorders 6 7.

Combined Types and Clinical Implications

Many children exhibit features of more than one type. Combined types are associated with a higher risk of concurrent tracheomalacia or bronchomalacia, especially in premature infants or those with comorbidities 8. The clinical course and severity cannot be predicted solely based on the endoscopic appearance, underlining the importance of a comprehensive evaluation 8 9.

Causes of Laryngomalacia

Despite its frequency, the exact cause of laryngomalacia remains incompletely understood. Theories range from anatomical abnormalities to neuromuscular and inflammatory factors.

Cause/Theory	Mechanism/Description	Evidence/Notes	Source(s)
Neuromuscular Dysfunction	Weakness or poor tone of laryngeal muscles	Sensorimotor integration deficits	12 15
Anatomic Factors	Abnormal supraglottic tissue, redundant mucosa	Direct visualization, variable anatomy	7 8 9
Gastroesophageal Reflux	Acid exposure causing laryngeal edema	Nearly universal in affected infants	11
Inflammatory/Other	Possible role for inflammation, vitamin D	Emerging theories, not definitive	13
Relative Imbalance	Airflow demand exceeds airway support	Newer theory, needs validation	14
Acquired Causes	Neurological insults postnatally	Rare, documented in case reports	15

Table 3: Theories and Causes of Laryngomalacia

Neuromuscular and Sensorimotor Integration

Recent research suggests many cases stem from abnormal neuromuscular control of the larynx. Weakness or poor tone in the muscles controlling supraglottic structures leads to their collapse during inhalation. This may be due to impaired sensorimotor integration at the brainstem level or disruption of laryngeal reflexes 12 15. In some cases, an underlying neurological disorder or injury can trigger or exacerbate symptoms 15.

Anatomic Abnormalities

Structural variations—such as shortened aryepiglottic folds or redundant supraglottic mucosa—are commonly seen on endoscopic examination. However, anatomical findings alone do not always predict symptom severity, as functional factors play an important role 7 8 9.

Gastroesophageal Reflux

Virtually all infants with laryngomalacia have some degree of reflux, with gastric acid reaching the pharynx and larynx 11. Reflux may worsen laryngeal edema and tissue flaccidity, exacerbating symptoms and airway compromise 11.

Inflammatory and Other Factors

Emerging theories implicate possible inflammatory mechanisms, including a potential role for vitamin D deficiency 13. However, evidence is still limited.

Relative Imbalance Theory

A newer concept proposes that laryngomalacia arises when the demand for airflow exceeds the structural support capacity of the larynx, creating turbulent airflow and negative pressure that collapses supraglottic tissues 14. This model may help explain variability in presentation and progression.

Acquired Laryngomalacia

Though rare, laryngomalacia can also be acquired after birth, particularly following neurological insults or trauma. Such cases are uncommon but highlight the importance of considering broader etiologies in atypical presentations 15.

Treatment of Laryngomalacia

Treatment is individualized, ranging from careful observation to surgical intervention. Most infants improve without surgery, but those with severe symptoms or complications require prompt and tailored management.

Approach	Indications	Outcomes/Notes	Source(s)
Observation	Mild to moderate cases, no growth failure	Symptoms often resolve by 7–18 months	2 4 5 10
Medical Management	Reflux control, nutritional support	Adjunct to observation/surgery	5 11
Surgery (Supraglottoplasty)	Severe airway or feeding compromise	High success, especially in select types	1 4 16 18 19
Tracheostomy	Life-threatening obstruction, failed surgery	Rarely needed	5 17 18

Table 4: Main Treatment Approaches

Observation and Conservative Management

Most infants with laryngomalacia—about 80–90%—will experience spontaneous resolution of symptoms by 12–18 months of age, with the average being around 7–8 months 2 4 5. Regular monitoring of weight gain and respiratory status is essential. Mild cases may require no more than reassurance and periodic follow-up 2 4 5 10.

Medical Management

Because reflux is nearly universal in these infants, anti-reflux therapy (such as proton pump inhibitors or H2 blockers) is often prescribed. Nutritional support, including feeding modifications or, rarely, temporary nasogastric tube feeding, may be necessary in infants with significant feeding difficulties 5 11.

Surgical Intervention

Surgery is reserved for severe cases—characterized by failure to thrive, significant airway obstruction, or life-threatening events. The most common procedure is supraglottoplasty, which involves trimming redundant tissue and, if needed, stabilizing the epiglottis 1 16 17 18 19. This minimally invasive approach has largely replaced tracheostomy for most surgical candidates, with high rates of symptomatic improvement and low complication rates 1 18 19.

CO₂ laser supraglottoplasty, in particular, has demonstrated effectiveness in improving symptoms, especially in patients with certain anatomical types or combined forms of laryngomalacia 1. However, outcomes are less favorable in those with neurological comorbidities 1 18.

Tracheostomy and Other Interventions

Tracheostomy is now rarely required and reserved for cases where supraglottoplasty fails or in the presence of severe comorbidities such as tracheomalacia, pulmonary disease, or vocal cord paralysis 5 17 18.

Follow-up and Prognosis

The majority of children recover fully with appropriate management. However, those with comorbidities or severe forms may require ongoing multidisciplinary care 1 5 8 18. Long-term outcomes are generally excellent, but persistent disease, supraglottic stenosis, or lower respiratory infections can occur in rare cases following surgery 18.

Conclusion

Laryngomalacia is a complex but often self-limited condition. While most infants experience mild symptoms and outgrow the disorder, a minority develop severe disease requiring intervention. Early recognition, careful monitoring, and individualized management are paramount.

Key Takeaways:

• Laryngomalacia is the leading cause of stridor in infants, usually presenting within the first days or weeks of life 2 3 5.
• Symptoms range from mild stridor to severe airway obstruction and feeding difficulties; indicators of severity include retractions, cyanosis, failure to thrive, and apnea 1 3 4 5.
• Multiple anatomical and pathophysiological types exist, and combined forms are common; comorbidities increase the risk of severe disease 7 8 9.
• Causes are multifactorial, involving neuromuscular dysfunction, anatomical factors, and nearly universal gastroesophageal reflux 7 11 12 15.
• Most cases resolve spontaneously with observation; severe cases benefit from surgical intervention, with supraglottoplasty offering high rates of improvement 1 4 16 18.
• Tracheostomy is now rarely needed and reserved for the most severe or refractory cases 5 17 18.
• Long-term prognosis is excellent in the majority of cases with appropriate management 2 4 5.

By understanding the spectrum of laryngomalacia, clinicians and families can work together to ensure timely diagnosis and effective, personalized care.