Can i take fexofenadine and benedryl together. or is there something else i can do to help with a dust mite allergy?

Dust mite allergy: If it is true, i.e. Documented by testing, environmental control is the first step in therapy: pillow and mattress covers, dust proofing your place, etc. drug therapy depends on the organ(s) affected, upper or lower airways or skin,, finally allergen immunotherapy. All this requires assessment/follow up with an allergist, if you have access to one, but simply doubling up on antihistamines won't help

Yes and yes: Though not risky, the above med combination is hart on many. The benedryl makes many people drowsy so it can interfere with life. There are OTC nasal steroid sprays that can decrease symptoms.Your nasal membranes are often the site where most discomfort is triggered. The sprays (rhinocort,nasocort,etc.) take several days to make a difference, but might help if used daily.