Iatrogenic Subglottic Stenosis in Mast Cell Activation Syndrome: A Sentinel Case and Narrative Review.

Subglottic stenosis (SGS) may arise from both mechanical and inflammatory airway injury. Patients with mast cell activation syndrome (MCAS) are uniquely vulnerable, due to both direct effects of systemic inflammation and indirect effects of repeated intubation for anaphylaxis that can converge to cause life-threatening airway compromise. We describe a sentinel case of a 34-year-old female with MCAS and multiple prior intubations who presented with progressive dyspnea. Flexible laryngoscopy revealed grade III SGS. She underwent urgent endoscopic intervention, including balloon dilation, carbon dioxide (CO2) laser radial incisions, and steroid injection. Airway patency was restored, and postoperative care focused on optimizing systemic mast cell control with cromolyn, fexofenadine, montelukast, and omalizumab. Literature review supports a mechanistic role for mast cell mediators in airway fibrosis and impaired wound healing, compounding the effects of mechanical trauma in MCAS. This sentinel case highlights clinically significant risk of SGS in patients with MCAS. By integrating case findings with mechanistic insights, this report underscores the urgent need for interdisciplinary awareness, proactive airway evaluation, and research into surveillance and prevention strategies in MCAS and related disorders.Level of Evidence: Level V/Case Report and Narrative Review.