Slight itchy rash on face after using patanase... is this a reaction and should i stop using it?

Not likely: Patanase is an anithistamine type nasal spray approved for treating allergies. It would be unlikely for this to cause a rash. If the medications is stopped and rash resolves, then medication is restarted and rash reoccurs, this suggests the medication. Other causes are more likely. Also nice to have many medications available to treat allergies.

Rash from patanase: It is possibly related to the patanase. The easiest thing to do is to stop the medication and see if the rash goes away. If and when the medication is restarted and the rash reappears then you likely have your answer.