Facial Barotrauma Mimicking Trauma: A Forensic Case of Mask Squeeze in a Diving Fatality.

Periorbital ecchymosis - commonly known as "raccoon eyes" - is a classical indicator of traumatic head injury, particularly basilar skull fractures. However, similar findings may also arise from non-traumatic causes, including systemic disease and barotrauma. We report a rare forensic case of bilateral periorbital ecchymosis caused by facial barotrauma in the absence of external trauma, observed in a fatal skin diving incident. A healthy man in his 20s lost consciousness during the second dive of a recreational session and was recovered from a depth of approximately 20 m. The presence of periorbital ecchymosis initially raised suspicion of head trauma. However, forensic autopsy revealed no skull or facial fractures or intracranial injury. Video footage and scene investigation confirmed the event was a non-violent solo accident. Based on the integration of contextual and pathological findings, the periorbital ecchymosis was attributed to facial barotrauma resulting from an inability to equalize mask pressure after loss of consciousness. This case highlights the importance of recognizing facial barotrauma as a potential mimicker of traumatic injury in water-related deaths. A thorough forensic investigation, including autopsy, scene analysis, and ruling out underlying disease, is essential for accurate diagnosis. Awareness of this mechanism can help prevent misinterpretation and support more reliable medicolegal conclusions.