Iatrogenic cerebrospinal fluid leak after repeated nasal swab tests for COVID-19: illustrative case

BACKGROUND: Nasal swab tests are one of the most essential tools for screening coronavirus disease 2019 (COVID-19). The authors report a rare case of iatrogenic cerebrospinal fluid (CSF) leak from the anterior skull base after repeated nasal swab tests for COVID-19, which was treated with endoscopic endonasal repair. OBSERVATIONS: A 41-year-old man presented with clear continuous rhinorrhea through his left nostril for 5 days after repeated nasal swabbing for COVID-19. There were no obvious risk factors for spontaneous CSF leak. Computed tomography cisternography showed contrast accumulation in the left olfactory fossa and along the left nasal cavity. Such findings aligned with a preliminary diagnosis of CSF leakage through the left cribriform plate. Magnetic resonance imaging confirmed the presence of a CSF fistula between his left cribriform plate and superior nasal concha. The patient underwent endoscopic endonasal repair. CSF rhinorrhea ceased after the surgery, and no recurrence was noted during the 12-week postoperative follow-up period. LESSONS: Although rare, iatrogenic CSF leakage can be a serious complication following COVID-19 nasal swab tests, especially when infection may cause significant neurological sequelae. Healthcare providers should become familiar with nasal cavity anatomy and be well trained in performing nasal swab tests.