Subcutaneous emphysema
Updates to Article Attributes
Subcutaneous emphysema, strictly speaking, refers to air in the subcutaneous tissues. But the term is generally used to describe any soft tissue emphysema of the body wall or limbs, since the air often dissects into the deeper soft tissue and musculature along fascial planes.
Clinical presentation
Clinically it is felt as crepitus and, if extensive, may cause soft tissue swelling and discomfort. Even when severe subcutaneous emphysema is typically benign, although complications such as airway compromise, respiratory failure, pacemaker malfunction and tension phenomena have been described.
Pathology
Causes of subcutaneous emphysema can be divided into:
- gas arising internally
- pneumothorax
- pneumomediastinum
- pulmonary interstitial emphysema
- perforated hollow viscus in the neck, e.g. oesophageal perforation
- fistula tract
- gas introduced externally
- penetrating trauma
- post-surgical
- post-percutaneous intervention, e.g. pleural drain insertion
- gas produced de novo
- gas producing infection(s), e.g necrotising fasciitis
Radiographic appearance
Plain film
If affecting the anterior chest wall, subcutaneous emphysema can outline the pectoralis major muscle, giving rise to the ginkgo leaf sign 2.
CT chest
Subcutaneous emphysema is readily visible on CT scans, with pockets of air seen as extremely dark low (air) attenuation areas in the subcutaneous space.
Treatment and prognosis
Treatment is directed at the underlying cause, while the subcutaneous air is absorbed by the body over time. Symptomatic management should also be provided.
However in rare instances managementwhere the subcutaneous air is compromising overlying soft tissue or causing a compartment syndrome management may involve release of the air by surgical division of the soft tissues or percutaneous drain insertion of catheters.
-<li>post-percutaneous intervention, e.g. <a title="Thoracentesis" href="/articles/thoracentesis">pleural drain insertion</a>- +<li>post-percutaneous intervention, e.g. <a href="/articles/thoracentesis">pleural drain insertion</a>
-</ul><h4>Radiographic appearance</h4><h5>Plain film</h5><p>If affecting the anterior chest wall, subcutaneous emphysema can outline the <a href="/articles/pectoralis-major-1">pectoralis major muscle</a>, giving rise to the <a href="/articles/ginkgo-leaf-sign">ginkgo leaf sign</a> <sup>2</sup>.</p><h5>CT chest</h5><p>Subcutaneous emphysema is readily visible on CT scans, with pockets of air seen as extremely dark low (air) attenuation areas in the subcutaneous space.</p><h4>Treatment and prognosis</h4><p>Treatment is directed at the underlying cause, while the subcutaneous air is absorbed by the body over time. Symptomatic management should also be provided.</p><p>However in rare instances management may involve release of the air by surgical division of the soft tissues or insertion of catheters.</p>- +</ul><h4>Radiographic appearance</h4><h5>Plain film</h5><p>If affecting the anterior chest wall, subcutaneous emphysema can outline the <a href="/articles/pectoralis-major-1">pectoralis major muscle</a>, giving rise to the <a href="/articles/ginkgo-leaf-sign">ginkgo leaf sign</a> <sup>2</sup>.</p><h5>CT chest</h5><p>Subcutaneous emphysema is readily visible on CT scans, with pockets of air seen as extremely dark low (air) attenuation areas in the subcutaneous space.</p><h4>Treatment and prognosis</h4><p>Treatment is directed at the underlying cause, while the subcutaneous air is absorbed by the body over time. Symptomatic management should also be provided.</p><p>However in rare instances where the subcutaneous air is compromising overlying soft tissue or causing a compartment syndrome management may involve release of the air by surgical division of the soft tissues or percutaneous drain insertion.</p>