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:
Breathing in cocaine
Corrosives or chemical burns of the esophagus
Forceful vomiting" (Boerhaave's syndrome)
Pertussis (whooping cough)
Certin medical procedures that insert a tube into the body, 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 after certain infections, including gas gangrene.
Call your health care provider if
Most of the conditions that cause subcutaneous emphysema are very severe, and you are likely already being treated by a doctor. Sometimes a hospital stay is needed, especially if due to an infection.
Wolfson AB. ed: Harwood-Nuss' Clinical Practice of Emergency Medicine. 5th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2010.
Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, and Stephanie Slon.