A Creepy Case of Recurrent Stridor: Circumferential Subglottic Hemangioma Diagnosed by Empiric Propranolol

Subglottic hemangioma (SGH) is a rare but potentially fatal cause of infantile stridor that is frequently misdiagnosed as laryngomalacia, croup, or idiopathic subglottic stenosis. Circumferential involvement is an uncommon and particularly dangerous variant whose endoscopic appearance overlaps with that of other concentric subglottic lesions, including congenital cricoid cartilage malformation and idiopathic subglottic stenosis. We present a two-week-old female with a history of preterm birth (36 5/7 weeks) and progressive biphasic stridor, cyanosis, and increasing respiratory distress. Operative microlaryngoscopy and bronchoscopy demonstrated significant subglottic narrowing of uncertain etiology that was refractory to balloon dilation, and contrast-enhanced MRI of the neck demonstrated nonspecific airway narrowing without an identifiable mass. After multidisciplinary discussion with hematology and neonatology, empiric oral propranolol was initiated for presumed airway hemangioma. The infant's stridor improved dramatically within five days and resolved completely; she was discharged after a one-month neonatal intensive care unit stay and remained asymptomatic at seven-month follow-up. This case illustrates the diagnostic ambiguity that can attend circumferential subglottic narrowing in the neonate and demonstrates that empiric propranolol can serve as both a diagnostic and therapeutic trial when imaging is unrevealing.