Subcutaneous emphysema occurs when air gets into tissues under the skin. This usually occurs in the skin covering the chest wall or neck, but can also occur in other parts of the body.
Crepitus; Subcutaneous air; Tissue emphysema
Subcutaneous emphysema can often be seen as a smooth bulging of the skin. When a health care provider feels (palpates) the skin, it produces an unusual crackling sensation as the gas is pushed through the tissue.
This is a rare condition. When it does occur, possible causes include:
Collapsed lung (pneumothorax), often occurring with a rib fracture
Facial bone fracture
Ruptured bronchial tube
This condition can happen due to:
Forceful vomiting" (Boerhaave's syndrome)
Gun shot wounds
Rarely after medical procedures such as endoscopy, a central venous line, intubation, and bronchoscopy
Air can also be found in between skin layers on the arms and legs or torso during certain infections, including gas gangrene.
When to Contact a Medical Professional
Most of the conditions that cause subcutaneous emphysema are very severe. Sometimes a hospital stay is needed. Medical staff should already be involved in most cases.
Eric Perez, MD, Department of Emergency Medicine, St. Luke's-Roosevelt Hospital Center, New York, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.