Benign Subcutaneous Emphysema of the Lower Limb Following a Trivial Injury: A Case Report.

Subcutaneous emphysema involves air entrapment beneath the subcutaneous tissue and fascial planes. It can range from a benign condition to a life-threatening emergency. Benign subcutaneous emphysema is typically confined to the subcutaneous tissues, lacks systemic features, and is non-progressive. We report a case of benign subcutaneous emphysema following a trivial trauma to the left leg of a 16-year-old male. Examination revealed a localized puncture wound and palpable crepitus. Following debridement of the puncture wound, the patient was managed conservatively with a below-knee posterior slab and antibiotics. Complete resolution of symptoms was achieved after two weeks. Subcutaneous emphysema in the lower limb is a rare, benign condition that must be carefully distinguished from severe, life-threatening necrotizing soft-tissue infections such as gas gangrene. While infectious etiologies demand immediate, aggressive surgical intervention, benign variants can be safely managed conservatively if the patient's systemic condition remains stable. Temporary joint immobilization prevents the progression of the "ball-valve" mechanism, leading to complete resolution within one to three weeks. Proper clinical evaluation through a meticulous history, physical examination, and basic radiological investigations helps differentiate benign subcutaneous emphysema from lethal surgical emergencies. Early identification guides appropriate conservative management, preventing unnecessary surgical intervention and extensive, prolonged antibiotic treatment.