Figure 4 Arrows indicate site of incisions. Laryngomalacia is the most common cause of noisy breathing, stridor, in infants. Other problems which cause similar symptoms include paralysis of the vocal cords, narrowing or partial blockage at the level of vocal cords or just below and rare tumors. Most patients with laryngomalacia have stridor in some but not all positions. Only in severe cases are there associated retractions of the chest wall, difficulty breathing, and failure to thrive because of difficulty feeding.
Most patients have no other health problems.
The cause of laryngomalacia is unknown although it may be an immaturity of the cartilage of the larynx, or immaturity of the nervous system controlling the larynx. Most patients can be diagnosed quite easily in the clinic by performing a brief nasopharyngoscopic examination. Occasionally the physician will recommend further diagnostic testing including xrays, microlaryngoscopy, or bronchoscopy, in order to perform a more thorough evaluation of the airway. In particular, this is performed when symptoms are severe or an adequate diagnosis can not be made by simpler tests. The symptom of inspiratory stridor resolves completely by age one year to 18 months.