Fig. 5From: The needle and the damage done: musculoskeletal and vascular complications associated with injected drug usePlain radiograph (a) and ultrasound image (b) of an intravenous drug user presenting with severe forearm pain and erythema. Gas within the subcutaneous tissues is demonstrated on plain radiograph as lucency within the soft tissues (red arrow). On ultrasound a subcutaneous soft tissue abscess with internal gas artefact (red arrow) and overlying changes of cellulitis is seen. Appearances are concerning for necrotising fasciitis and prompt surgical debridement was advisedBack to article page