[grumpy-de-sre]

You can always go to an allergist for a skin prick test.

I'd say hallmark symptom would be chronic night time congestion worsening while in bed (an area of the house that has a very high density of mite allergen).

But running a bit of differential diagnosis on this,

* Inflammatory & Allergic Conditions (allergic/non-allergic rhinitis, chronic rhinosinusitis, turbinate hypertrophy, nasal polyps).

* Obstructive Sleep Apnea (do a STOP-BANG).

* Structural Blockages & Airway Obstructions (deviated septum, adenoid/tonsil hypertrophy, nasal valve collapse, turbinate hypertrophy).

* Gastroesophageal Reflux Disease (GERD/LPR).