stridor

Stridor is a high-pitched, often musical sound produced by turbulent airflow through a narrowed or obstructed upper airway. It is typically heard on inspiration and reflects an abnormality from the nose or throat through the larynx. Inspiratory stridor suggests obstruction above the thoracic inlet, while biphasic stridor can indicate involvement of the glottis or subglottic region.

In children, common causes include croup (laryngotracheobronchitis), epiglottitis, foreign body aspiration, laryngomalacia, and congenital subglottic stenosis. Croup usually presents with a barking cough and mild fever; epiglottitis (now rare due to vaccination) presents with rapid throat pain, drooling, and reluctance to swallow. In adults, stridor may arise from allergic reactions, trauma, infections, tumors, or vocal cord dysfunction.

Evaluation focuses on airway status and the severity of respiratory distress. Red flags include stridor at rest, marked tachypnea, drooling or dysphagia, cyanosis, inability to speak, or agitation. Physical examination should prioritize safety and avoid provoking airway compromise. Imaging can aid assessment in some cases: lateral neck radiographs may show a thumbprint sign in epiglottitis, and anteroposterior views can show the steeple sign in croup. Definitive diagnosis may require direct visualization with laryngoscopy or bronchoscopy, depending on the suspected cause.

Management is cause-specific and airway-centered. Mild stridor at rest may be observed with supportive care. Croup is treated with corticosteroids and, for moderate to severe cases, nebulized epinephrine; humidified air and fluids support. Epiglottitis requires securing the airway in a controlled setting and IV antibiotics. Foreign bodies warrant urgent removal. Laryngomalacia and many mild congenital lesions often improve with age. Vaccination has reduced some causes of epiglottitis.