Severe persistent allergies can be treated with newer options of treatment like leukotreine inhibitors, allergy shots, mast cell inhibitors etc. These options should be chosed considering individual symptoms and their severity. Best.
I like Omnaris Nasal Allergy Spray, but it is available through prescription only. If you are looking for OTC allergy meds, Clariton has a good safe reputation, (the gerneric brand is fine) and the standard "good old fallback" is Benedryl, which is also safe and has been around a long long time. Good luck!