Unilateral Clear Thin Rhinorrhea: How Often Is It a Cerebrospinal Fluid Leak?

NAR was the most common cause of UCTR, representing nearly 50% of cases. However, CSF rhinorrhea still represented 30% of cases, reinforcing that UCTR should be worked up for CSF rhinorrhea, ideally with B2-Tf testing. BMI ≥30, ages 45-64 years, and patient-reported higher volume UCTR were positively associated with CSF rhinorrhea. If B2-Tf testing is negative or unobtainable, or clinical suspicion for CSF leak is low, clinicians can consider starting medical therapy for rhinitis or rhinosinusitis before pursuing further invasive CSF confirmatory testing.