Question: do allergies cause post nasal drip?
Answer: Allergic Rhinitis as a Cause of Post Nasal Drip Post nasal drip may be a symptom of allergic rhinitis (hayfever) although it's quite uncommon to have post nasal drip as the only symptom. 2﻿ Typically, allergic rhinitis symptoms also include sneezing, nasal congestion, and a runny, itchy nose.