Introduction
Subcutaneous emphysema is a condition in which air becomes trapped underneath the dermal layers of skin. The development of subcutaneous air is a benign symptom or an indication of a deeper, more concerning pathologic disease state. A history of head and neck injury can raise suspicion and lead towards the identification of the cause of subcutaneous air collection. Though temporal bone fractures are a commoner entity in otorhinolaryngologic traumatology, published cases of traumatic mastoid fractures are extremely rare in English literature.
Air may enter the subcutaneous neck tissues via penetrating or closed non-penetrating external neck injuries. Air can also be intraluminally dispersed in the neck and chest iatrogenically, or due to rupture of a preexisting anatomical abnormality. Cervical and mediastinal emphysema has been reported in a few cases post-tonsillectomy. Last but not least, facial trauma and dental or maxillofacial procedures can have a similar result. 1,2.
In our report, we present a case of mastoid apex fracture caused by a high-velocity impact trauma leading to bilateral subcutaneous cervical emphysema. Though unclear from the anamnesis, we believe the Valsalva maneuver performed by the patient during nose-blowing, caused the spread and entrapment of air through the soft tissue layers of the neck.