Brief Answer:
there are some potential causes

Detailed Answer:
Hello,

At this time of year infectious causes predominate. Although it may sound strange due to its duration, it could be viral rhinitis (and perhaps more than one infection). You haven't mentioned any other symptoms so I take it for granted that you didn't have fever, sore throat, sneezing, itchy nose/eyes, headache, etc.

Allergic rhinitis is another consideration but most patients also experience accompanying symptoms like eye irritation, sneezing, etc.

Simple causes like temperature changes is another potential cause. When the nose gets cold it starts to drip. Getting back to a warm environment is enough to stop the dripping.

Prolonged usage of decongestants may also cause rhinitis medicamentosa, in other words, rhinitis caused by drugs. Although the decongestants are fine during the first week of use, they start to become less and less efficient after prolonged use and the patients tend to require more frequent doses for a progressively diminishing effect.

Finally, other drugs may also contribute or even cause rhinitis like beta blockers, NSAIDs, hormones, etc.

Trying an antihistamine and perhaps a corticosteroid nasal spray may help with the symptoms (and suggest allergic etiology).

I hope you find my comments helpful!
Kind Regards!
Dr.Panagiotis Zografakis

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