Steeple sign
| Steeple sign | |
|---|---|
| The steeple sign as seen on an anteroposterior neck X-ray of a child with croup | |
| Differential diagnosis | Croup |
The steeple sign is a radiographic sign found on a frontal neck radiograph which is characterized by subglottic tracheal narrowing.[1] The radiographic appearance is similar to the pointed shape of a Christian church steeple within the trachea itself.[2][3] The steeple sign is most commonly associated with croup,[2][3] or laryngotracheobronchitis, which is an upper airway infection that causes inflammation of the larynx and trachea.[4]
Radiographic features
The steeple sign is typically seen on an anteroposterior radiograph of the neck as a symmetric narrowing of the subglottic airway.[1][5] This creates a tapered look of the trachea, which occurs just below the level of the vocal cords and may extend into the upper portion of the trachea.[2] The resulting shape resembles a Christian church steeple.[3][2]
Pathophysiology
The steeple sign occurs as a result of inflammation in the subglottic region of the airway. The finding is most associated with croup, which is also known as laryngotracheobronchitis,[4] which is commonly caused by viral infections such as human parainfluenza virus. Inflammation can lead to edema, or swelling, which makes the subglottic region, the most narrow portion of the pediatric airway, susceptible to obstruction. Swelling of the airway mucosa in this region produces the characteristic narrowing seen on x-ray.[5]
Clinical significance
The presence of the steeple sign can support the diagnosis of croup in children with symptoms such as barking cough, inspiratory stridor, and hoarseness.[6] However, the steeple sign is not present in all cases and is not considered highly sensitive or specific for the condition.[7] Imaging is usually reserved for atypical presentations or when other causes of airway obstruction are being considered.[6]
Differential Diagnosis
Several conditions may produce radiographic findings similar to the steeple sign. These include epiglottitis, bacterial tracheitis, subglottic stenosis and airway obstruction due to foreign body aspiration.[4] Clinical findings and additional imaging are often needed to distinguish between these conditions.
References
- ^ a b Salour, Mozhdeh (August 2000). "The Steeple Sign". Radiology. 216 (2): 428–429. doi:10.1148/radiology.216.2.r00au18428. ISSN 0033-8419. PMID 10924564.
- ^ a b c d Braen, Richard (28 March 2012). Manual of emergency medicine (6th ed.). Philadelphia: Lippincott Williams & Wilkins. p. 203. ISBN 978-1451155686.
- ^ a b c Burket, Lester W.; Greenberg, Martin S.; Glick, Michael; Ship, Jonathan A. (2008). Burket's oral medicine (11th ed.). Hamilton, Ont: BC Decker. ISBN 978-1-55009-345-2.
- ^ a b c Matsuura, H; Shimanouchi, Y (2017-11-01). "Steeple sign and acute laryngotracheobronchitis". QJM: An International Journal of Medicine. 110 (11): 767. doi:10.1093/qjmed/hcx156. ISSN 1460-2725. PMID 29025139.
- ^ a b Defendi, Germaine L (18 January 2024). "Croup: Practice Essentials, Etiology, Epidemiology".
- ^ a b Hoyt, Karen Sue; Shea, Sheila Sanning (2015). "Steeple sign: a case of croup". Advanced Emergency Nursing Journal. 37 (2): 79–82. doi:10.1097/TME.0000000000000061. ISSN 1931-4493. PMID 25929218.
- ^ Yang, Wen-Chieh; Hsu, Yu-Lung; Chen, Chun-Yu; et al. (2019-11-29). "Initial radiographic tracheal ratio in predicting clinical outcomes in croup in children". Scientific Reports. 9 (1): 17893. doi:10.1038/s41598-019-54140-y. ISSN 2045-2322. PMC 6884517. PMID 31784540.
External links