Subcutaneous emphysema (Crepitus or Sub Q air)


Subcutaneous emphysema is a condition caused by the pathologic accumulation of air  underneath  the skin of the skin or neck. The presence of air in the loose subcutaneous areolar tissue and muscle.

subcutaneous emphysema of pectoralis

  • Bue circle: characteristic of subcutaneous emphysema with muscle bundles of pectoralis muscle becoming visible.
  • Red arrow : points to subcutaneous emphysema in the supraclavicular area.
  • White arrow: points to streaky air visible in the mediastinum


  • Unusual crackling senstation upon palpitation (touch) of the skin as the gas is forced through layers of tissue.
  • smooth bulging of the skin may be observed

Subcutaneous emphysema a result of the following  conditions:

  • Pneumothorax, Collapsed lung often  occurring after a rib fracture
  • Facial bone fracture, of ten occuring after ethmoid or maxillary sinus fractures
  • Ruptured bronchial tube
  • Ruptured esophagus

The above conditions often a result of the following trauma:

  • Blunt trauma
  • Gun shot wounds
  • Stabbing 2009. Subcutaneous emphysema. Retrived April 7, 2009 from

 University of Maryland Medical Center. 2009. Subcutaneous emphysema. Retrived April 7, 2009 from