Posted 6/3/2016 9:00 PM (GMT -7)
It really depends on the Dr as to whether they want to see the rash or take your word for it. Most will trust you, but still would much rather see for themselves, which makes perfect sense, as I'm sure we don't describe things they way they would, and we might not observe all the things they'd be looking for. This applies to rashes as well as other visible symptoms.
Time to diagnosis really depends on your symptoms - if you are showing lots of definitive symptoms you would obviously be diagnosed more quickly than if your symptoms are more vague. Some people remain borderline for years, sometimes it's more obvious. And some Drs are more hesitant to apply a label than others.
The most important thing is that your symptoms are being treated so that you can feel as well as possible. (Except that if you are trying to get disability, you do need a firm diagnosis as quickly as possible.)