Welcome to Sclero Forums! I'm sorry you have a face rash.
As it happens, scleroderma would be the rarest possible cause of any face rash. I think you are likely referring to morphea scleroderma, which actually occurs in patches (not as a rash per se). You can read about morphea and also look at the photos of it.
What I'd recommend -- and please bear in mind I'm not a doctor and have no medical training at all -- is that you go back to your dermatologist and ask for further investigation. Things on the face are often difficult to identify because we usually don't want a skin biopsy taken on our face unless there is a suspicion of something serious like cancer.
Also make sure that you are seeing a board certified dermatologist and one who is interested in skin diseases. The problem is that many dermatologists specialize in only certain things, such as skin cancer or plastic surgery. Take the time to read their biographies and select your dermatologist carefully. If you are not satisfied, get a second opinion from another dermatologist.
Many of us here know what it is like to seem brushed off, at first, when doctors don't quite know what is wrong. So it takes persistence, sometimes returning again and again and pressing for answers. Also be sure that you are following all their directions. For example, sometimes people with rosacea need to use medication but also find and avoid all their triggers, such as spicy foods or alcohol, etc.
Keep in touch and let us know what you find out, okay?