RESUMO
Necrotising fasciitis (NF) is a rapidly progressive soft tissue infection involving necrosis of subcutaneous tissues. Early surgical intervention reduces mortality, but initial clinical findings are often non-specific and can delay the diagnosis. An 80-year-old patient, presented to our emergency department with pain in her left hip and mild bruising following a fall. An x-ray, requested to investigate a possible hip fracture, in fact demonstrated air in the subcutaneous tissues. She rapidly deteriorated and soon developed blood-filled blisters, crepitus and fixed staining of the skin. She underwent urgent debridement of involved tissues in theatre confirming the diagnosis of NF. The presence of subcutaneous emphysema on plain radiograph as in this case, is extremely specific to the diagnosis of NF. Although other imaging modalities can aid diagnosis these remain as an adjunct rather than a definitive diagnostic tool and should not delay surgical intervention based on clinical findings.