In radiology, the steeple sign is a radiologic sign found on a frontal neck radiograph where subglottictracheal narrowing produces the shape of a churchsteeple within the trachea itself.[1][2] The presence of the steeple sign supports a diagnosis of croup, usually caused by paramyxoviruses.[3] It can also be defined as the replacement of the usual squared-shoulder appearance of the subglottic area by cone-shaped narrowing just distal to the vocal cords. This is called the steeple or pencil-point sign.
References
^Braen, G. Richard (29 March 2012). Manual of Emergency Medicine. Lippincott Williams & Wilkins. p. 203. ISBN9781451153910. Radiologic confirmation of proximal narrowing of the subglottic space can be obtained by an AP radiograph of the neck; typically, a "steeple sign" is noted referring to the similar appearance of a church steeple.
^Burket, Lester William (2008). Burket's Oral Medicine. PMPH-USA. p. 304. ISBN9781550093452. This type of narrowing is typically present in croup and is known as the steeple sign on the anteroposterior radiograph given its similarity to a church steeple.