What Lies Beneath: Sub-diaphragmatic causes of subcutaneous emphysema – A Review

Air in the subcutaneous tissues, commonly described as subcutaneous emphysema, creates a distinctive clinical sign on palpation. In general, this results from an air leak from the airways or lungs forcing air in the mediastinum to move between soft tissue planes. This review aims to draw attention to alternative origins of subcutaneous air, specifically from bowel perforations below the diaphragm, in order to reduce the consequences of a delayed diagnosis. Patients presenting with subcutaneous emphysema without an obvious intra- thoracic cause should lead the clinician to consider acute intra-abdominal pathology, such as bowel perforation, especially after endoscopic procedures.