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

Area of Science:

• Otolaryngology
• Rhinology
• Neurology

Background:

• Unilateral clear thin rhinorrhea (UCTR) can be caused by various conditions, including cerebrospinal fluid (CSF) leaks.
• Accurate diagnosis is crucial to differentiate benign causes from potentially serious CSF rhinorrhea.

Purpose of the Study:

• To determine the frequency of conditions causing UCTR.
• To assess clinical features associated with CSF rhinorrhea.

Main Methods:

• Retrospective review of patients presenting with UCTR over a 6-year period.
• Collected data included demographics (age, BMI, gender, race) and self-reported drainage volume.
• Conditions causing UCTR were recorded.

Main Results:

• 146 out of 3,041 patients (4.8%) had UCTR.
• Nonallergic rhinitis (NAR) was the most common cause (45%), followed by CSF rhinorrhea (30%).
• CSF rhinorrhea was associated with BMI ≥30, ages 45-64 years, and collectable UCTR.

Conclusions:

• NAR is the leading cause of UCTR, but CSF rhinorrhea remains a significant concern.
• Clinical factors like higher BMI and age can indicate a higher likelihood of CSF rhinorrhea.
• Consider B2-Tf testing for suspected CSF leaks, with medical rhinitis therapy as an alternative for low-suspicion cases.