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Steeple sign

Head & NeckRadiograph

Symmetric tapering narrowing of the subglottic airway on a frontal neck radiograph, resembling a church steeple.

What it means

Subglottic oedema, classically due to croup (laryngotracheobronchitis).

Mechanism

Inflammatory oedema of the subglottic mucosa narrows the normally shouldered airway into a tapered point.

Associated conditions

  • Croup (viral laryngotracheobronchitis)
  • Bacterial tracheitis
  • Subglottic stenosis
  • Epiglottitis (variable)

Pearls

  • Croup is a clinical diagnosis; imaging is not usually required.
  • The narrowing is symmetric and subglottic, unlike a mass or asymmetric stenosis.

References

  • Radiopaedia: Steeple sign (croup)

For educational use only. This dictionary is a study aid and reference, not a diagnostic tool, and must not be used to guide clinical decisions or patient care. Imaging appearances vary; always correlate with the full clinical picture and confirm with a qualified radiologist.