[Clinical characteristics of 6 cases of relapsing polychondritis in children with airway involvement]

Objective: To investigate the pathogenesis, clinical signs and diagnosing procedures of relapsing polychondritis(RP) in children with airway involvement. Methods: The medical history, clinical symptoms, physical examination, electronic laryngoscopy and imaging findings of six patients were retrospectively analyzed. The patients diagnosed as relapsing polychondritis with involving the airway from January 2018 to December 2021 were in our hospital. The clinical features of the 6 cases were summarized. Results: All 6 patients were male, ranging in age from 8 years 1 month to 14 years 1 month, with a median age of 12.04 years. Stridor and dyspnea were observed in all patients, with hoarseness in 2 patients and frequently nocturnal dyspnea during sleep in 2 patients. Initially, all children were diagnosed as laryngitis or laryngotracheitis, and were treated symptomatically with glucocorticoids and aerosol inhalation. Immunosuppressants and targeted therapy with biologics were given after patients diagnosed as RP. All patients were ultimately required tracheostomy. The time from the onset of airway symptoms to tracheostomy ranged from 1 month to 27 months. Two children had a history of endotracheal intubation prior to tracheostomy. All 6 patients underwent electronic laryngoscopy, revealing involvement of the laryngeal and subglottic mucosa and cartilage structures, which showed gradual improvement with medical therapy. Computed tomography (CT) of the trachea with three-dimensional reconstruction was performed in all patients, demonstrating moderate to severe subglottic stenosis. Two patients exhibited complete airway obstruction at the C4-C6 cervical level. Three children underwent suspension laryngoscopy under general anesthesia and endotracheal mucosal biopsy.Of the 6 children, 3 presented with nasal tip collapse or saddle nose, 2 had auricular cartilage changed, and 1 had scleralinvolvement. One patient underwent PET-CT scanning, which revealed tracheal collapse, diffuse increase in FDG(Flurodeoxyglucose)metabolism with increased FDG uptake in the nasal alar regions. All children were followed up for 2-3 years, 1 child died, while the remaining five continued to receive medical treatment. Conclusions: Relapsing polychondritis with airway involvement has an insidious onset and is difficult to diagnose. The airway stenosisresulting from RP is always severe and necessitating tracheotomy to maintain airway patency in the majority of cases.The treatment coursef or RP is prolonged, requiring long-term tracheostomy tube placement.