Late-Onset Laryngomalacia: A Variant of Disease

SAN DIEGO—Although the most commonly seen cases of laryngomalacia (LM) are in very young children, clinicians should consider late-onset LM as a potential cause of feeding difficulties in toddlers, sleep apnea in children, and teenage exercise intolerance, according to researchers at Cincinnati Children’s Hospital Medical Center and the Mayo Clinic.

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August 2007

The study was presented by Gresham T. Richter, MD, a clinical fellow in pediatric otolaryngology at Cincinnati Children’s Hospital Medical Center, as part of the American Society of Pediatric Otolaryngology’s program April 28 at the Combined Otolaryngology Spring Meeting.

Dr. Richter noted that the most common form of laryngeal anomaly is the congenital form seen in two-week- to three-month-old babies. They present with respiratory and feeding difficulties, clinically tied to gastroesophageal reflux disease (GERD), and the disorder is frequently self-limited to one or two years.

Although LM is rarely seen in older children, the research team believed that late-onset LM may be obscured by related but uncommon clinical features. They noted that there have been recent case reports regarding exercise-induced LM, “state-dependent” LM, and even acquired adult LM. Because late-onset LM appears to have atypical clinical features and diagnosis is often obscured and delayed, the Cincinnati Children’s Hospital—Mayo Clinic team attempted to clarify clinical features and management approaches for late-onset LM.

Their prospective and retrospective evaluation of patients with LM between 1998 and 2005 included children who were two years of age or older when diagnosed. From 17 patients identified, three specific groups were formed based on presenting symptoms and age:

  • Feeding difficulties—toddlers with a mean age of 3.3 years
  • Sleep disturbances—school-age children with a mean age of 6.3 years
  • Exercise intolerance—adolescents with a mean age of 15 years

According to Dr. Richter, profound arytenoid prolapse during nasopharyngeal and rigid endoscopy was discovered in all patients. Stridor was rarely present. Typical features of congenital disease, including omega-shaped epiglottis, shortened aryepiglottic folds, or retroflexed epiglottis, were not found. No patient was diagnosed with a neuromuscular disorder. And the research team noted that supraglottoplasty led to clinical cure in all patients.

Characteristics of Late-Onset LM

In looking closely at the three groups, the researchers found the following:

Feeding-Disordered LM

  • Toddlers with a mean age of 3.3 years
  • Cough and choke with food, variable weight loss and/or failure to thrive
  • No stridor
  • FEES-posterior-superior arytenoid redundancy and prolapse that worsened during feeds
  • All with GERD
  • Symptoms recalcitrant to medical management (such as feeding modification)

Sleep-Disordered LM

  • School-age children with a mean age of 6.3 years
  • Presentation of respiratory pauses, gasping, loud snoring, restlessness during sleep
  • Two patients with sleep-induced stridor
  • Abnormal polysomnograms
  • Despite prior T&A patients had persistent symptoms
  • 43% with GERD
  • Supra-arytenoid redundancy and prolapse during intraoperative nasopharyngoscopy and rigid microlaryngoscopy with very light sedation

Exercise-Induced LM

  • Adolescents with a mean age of 15 years
  • Strenuous activity induced symptoms of stridor, shortness of breath, retractions
  • Relieved with rest
  • Unlike exercise-induced asthma, it was unresponsive to inhaled B-agonist/Cromolyn
  • 67% with GERD
  • Patients underwent a treadmill test, hyperventilation study, and flexible laryngoscopy with evidence of supra-arytenoid prolapse during symptoms

Noting that late-onset LM is a clinically separate entity from the congenital form of LM that strikes very young babies, the researchers proposed that late-onset LM is made up of variants of LM, “not because it is late development of congenital disease,” they said, “but because they are late presentations of what we know LM to be.”

The team said that from an etiologic standpoint, late-onset LM logically is not due to immature laryngeal support, abnormal anatomy, or a neurologic insult, as seen in congenital and adult disease.

“We’d like to propose that these patients have a susceptible larynx at the supra-arytenoid level,” Dr. Richter said. “As the arytenoid redundance and prolapse become worse, increasing interruption of laryngeal sensitivity due to various factors such as GERD, hypoxia, and hypercarbia, as seen in these patients, contributes to an ongoing cycle. This is not a new concept. Because the larynx requires a stimulus in order to maintain a tone, via peripheral and central mechanisms, disruption of the stimulus can lead to reduced tone and subsequently supraglottic prolapse.”

Dr. Richter also noted that late-onset LM is likely exacerbated by GERD but is unlikely to resolve with time or GERD management. In these patients symptom resolution appears to require supraglottoplasty, he said.

©2007 The Triological Society