Uncontrollable sneezing when I get in bed

Patient: When I lie down to bed, I seem to have a bad allergy attack. My nose starts to itch and I feel like sneezing, my eyes start itching. I have washed all my bedding in hot water with fragrance free detergent. I have put allergy covers on all my pillows and mattress. I have cleaned my room so there is no dust. I even have an air purifier that is on while I sleep. I have changed where I sleep – like I’ll try to sleep on the couch to see if that changes the outcome and I still react the same way. I even went to sleep over at my mothers house and I got the same reaction. I don’t understand what this could be, or how to resolve the issue. I have taken most of the OTC allergy medications and they don’t help at all, unfortunately. Any advice?

Symptoms: Itchy nose, sneezing, itchy eyes, phlegm in throat