Which overexpansion injury generally causes a sensation of crackling when touched?

The sensation of crackling when touched is characteristic of subcutaneous emphysema. This condition occurs when air leaks into the subcutaneous tissues, often as a result of trauma or certain medical procedures, and it creates a distinctive popping or crackling sound when pressure is applied to the affected area. This sound arises because the air bubbles within the tissue are being compressed and released.

In contrast, conditions like mainstem bronchial rupture or pneumothorax involve air in the thoracic cavity rather than within the subcutaneous layers of the skin, so they do not produce the same tactile sensation. Media bronchial expansion refers to changes within the bronchi themselves, which wouldn’t be palpable in the same way. Understanding the underlying mechanisms of these conditions helps clarify why subcutaneous emphysema is linked to that specific sensation, while the others are not.