Been having persistent rash on face for several months. it goes away with oral steroids but then comes right back. what could it be?

Urticaria: If it goes away on steroids then it is an allergic reaction. If it comes back then it is an indication that the thing causing the allergy is still in your system - i would see your doc for full allergy testing to identify the cause.

Lupus.: It could be the butterfly rash of lupus (sle) but that is a far stretch and it could be several other autoimmune or inflammatory conditions which will require evaluation and blood work to better identify the cause.