Abstract: Objective To provide clinical references to otolaryngologists by investigating the clinical manifestations, underlying mechanisms, diagnosis, treatment, and prognosis of intracranial pneumatosis secondary to peritonsillar abscess incision. Methods We reviewed the relevant literature and retrospectively analyzed the clinical data of a patient with intracranial pneumatosis who underwent incisional drainage for a peritonsillar abscess in our hospital. Results The patient was almost asymptomatic in the early stage. As the disease progressed and gas accumulation increased, the patient presented with headaches and vomiting. According to the literature, intracranial pneumatosis can be life-threatening. Intracranial pneumatosis can be caused by various factors. However, it rarely arises spontaneously, without a history of cranial injury. Based on imaging findings, we suspect that in our patient, the intracranial pneumatosis was caused by external gases that entered the parapharyngeal space during surgical incision. As gases accumulate, a pressure difference is generated, and a “ball-valve” effect is induced. The gas is forced upward along the lumen surrounding the internal jugular vein and enters the skull through the jugular foramen. Conclusion Symptomatic intracranial pneumatosis due to a peritonsillar abscess incisional drainage is rare. It may be readily overlooked as the early symptoms are nonspecific. To optimize patient prognosis, otolaryngologists should be aware of the possibility of such complications and consider imaging examinations for early diagnosis and treatment.

Key words: Peritonsillar abscess, Intracranial pneumatosis, Parapharyngeal space, Jugular foramen, Early diagnosis