Steeple sign is characteristis of ?
**Core Concept**
The steeple sign refers to a radiological finding on chest X-ray or CT scan, characterized by the tapering of the upper lobe bronchi, giving a distinctive 'steeple-like' appearance. This sign is associated with a specific condition that affects the respiratory system.
**Why the Correct Answer is Right**
The steeple sign is typically seen in patients with **Tracheobronchomalacia**. Tracheobronchomalacia is a condition where the cartilaginous support of the trachea and bronchi is weakened, leading to abnormal collapse of these airways during expiration. This collapse results in the characteristic 'steeple-like' appearance on imaging. The steeple sign is often seen in patients with severe tracheobronchomalacia, particularly in those with underlying conditions such as chronic lung disease or neuromuscular disorders.
**Why Each Wrong Option is Incorrect**
**Option A:** The steeple sign is not typically associated with **Pneumonia**, which is an infection of the lung parenchyma and would not cause the characteristic bronchial tapering seen in tracheobronchomalacia.
**Option B:** **Bronchiectasis** is a condition characterized by the permanent dilation of the bronchi, which would not result in the tapering of the bronchi seen in the steeple sign.
**Option C:** **Tracheal stenosis** refers to a narrowing of the trachea, which would not typically result in the characteristic steeple-like appearance of the upper lobe bronchi.
**Clinical Pearl / High-Yield Fact**
The steeple sign is a key radiological finding in tracheobronchomalacia, and its recognition can help guide further management and treatment of patients with this condition.
**Correct Answer:** C.