What is steeple sign?

The steeple sign is a radiological term used to describe a narrowing of the airway that resembles the shape of a church steeple on an X-ray or CT scan. This narrowing is typically caused by conditions such as croup, epiglottitis, or tracheal stenosis.

The steeple sign is most commonly associated with croup, a viral infection that causes inflammation of the larynx and trachea, leading to difficulty breathing and a characteristic barking cough. In severe cases, croup can cause significant narrowing of the airway, resulting in the classic steeple sign on imaging studies.

Epiglottitis is another condition that can cause a steeple sign on imaging. This condition involves inflammation and swelling of the epiglottis, a flap of tissue that covers the windpipe during swallowing to prevent food from entering the airway. When the epiglottis becomes swollen, it can cause obstruction of the airway, leading to the steeple sign on imaging.

Tracheal stenosis, a narrowing of the trachea due to scarring or inflammation, can also result in a steeple sign on imaging studies. This condition can be caused by traumatic injury, chronic inflammation (such as from smoking or acid reflux), or previous surgeries on the airway.

Overall, the steeple sign is a useful radiological finding that can help clinicians diagnose and manage conditions affecting the upper airway. It is important to recognize this sign on imaging studies to guide appropriate treatment and prevent potential complications associated with airway obstruction.