Hi there, when you mentioned face rash, the first thing that comes to my mind is the butterfly face rash that people with lupus get. The rash that you get may or may not be due to that. It might be an allergic reaction or something... I defenitely can't tell and you have to go to a doctor for a blood test on it. You can search online and see if you can find any pictures of the butterfly rash. The 'butterfly rash' is caused by sun exposure. Did you get it after sun exposure?
Anyone can have an allergy at any point in their life. It doesn't mean that you are allergy-free when you don't have it as a child. It's best if you can check it with a dermatologist if the rash appears a second time.