A Case of Relapsing Polychondritis With Severe Obstructive Ventilatory Defect Caused by a Single Flare-Up.

Relapsing polychondritis (RP) is a rare progressive autoimmune disorder affecting cartilaginous and/or proteoglycan-rich structures. Tracheobronchial involvement is observed in almost half of RP cases and significantly impacts the prognosis. We present a case of RP with a rapidly progressive obstructive ventilatory defect caused by a single flare-up, despite significant improvements in the thickening of the airway walls after starting steroid administration. Although the airway walls appeared normal on computed tomography after starting treatment, tracheobronchial cartilage tissues were considered to have been extensively destroyed by chondritis, leading to tracheobronchomalacia and resulting in dynamic respiratory collapse. Preventing fibrosis of the airway walls caused by recurrent flare-ups will be extremely important to avoid fixed airway stenosis.