Is the musty smell in my blanket caused by dust mites or something else?

[Lia152]

Hi there.

Growing up, I didn't have any allergies besides the usual light stuff thanks to pollen; however, a couple years ago I seem to have discovered one. I spent at least a full year not going in the room at my dad's house, and when I returned, there was a distinct dusty smell in my comforter and clothes that I still have problems washing out. Now my SO has a blanket he'd kept rolled up under his bed for I'm guessing just as long, and it has the same smell. It causes me to sneeze like crazy, get swollen tonsils and a sore throat, and sometimes develop achy sinuses+postnasal drip for 2-3 days depending on how much exposure I get to it, and then pretty much a week to completely get over it. Apparently I'm the only one who can smell it, too. I've been reading up online about dust mites, but I just want to confirm if they're what's causing it.

Thanks.