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,
Been doing immunotherapy for allergies for 3 years and it is a complete game changer. Last year was the first year I could breathe through my nose for the entire year. No more stuffy months.
