[Subcutaneous emphysema, pneumomediastinum, pneumopericardium, pneumorachis, and pneumoretroperitoneum revealing an unknown foreign body aspiration].

Subcutaneous emphysema develops from the spread of air essentially from the mediastinum into the subcutaneous tissue causing progressive distension and infiltration. Diagnostic and therapeutic delay expose the patient to massive air effusion and risk of compression of cervical and mediastinal structures. The initial mechanism is a breach in the tracheobronchial tree with air diffusion into the interstitial space and along the perivascular spaces toward the mediastinum, and then spread and dissection in the subcutaneous tissue. A tracheobronchial foreign body is a very rare cause of emphysema and is often localized. An association with a combination of epidural emphysema, pneumopericardium, or pneumoretroperitoneum is exceptional. Here, we present a unique case associating massive subcutaneous emphysema, pneumomediastinum, pneumopericardium, pneumorrhachis, and pneumoretroperitoneum in a 3.5-year-old child complicating an unrecognized aspirated foreign body. The extraction of the foreign body resulted in gradual regression of the symptoms and the disappearance of these emphysematous locations.