Is it allergic to dust or milk?

Since you mentioned you have a history of dust mite allergies, it's very possible baby inherited a sensitivity, but milk protein allergies can also manifest as facial rashes. However, because the rash is increasing right around the eye area and looking a bit raised or blistered, it's best not to guess between the two on your own. Rashes near the eyes can get irritated easily by rubbing or even turn into a secondary bacterial infection if the skin barrier is broken. I'd highly recommend bringing baby to a pediatrician to get it looked at properly so they can give you a safe, eye-area-approved cream and help you figure out the exact trigger. Hope it clears up quickly!