So sorry your son is so ill. I'm glad they are following up to dx or rule out lupus. There are some links at the end of my signature that may be helpful. One of them is "4 of 11 Criteria" . . . that one shows the criteria for diagnosing lupus. There isn't a specific test, it is a combination of criteria and so the diagnosis can be frustrating and difficult. But, given the extent of your son's illness, I think the doctors will be able to make a faster determination.
There are several overlapping diseases/conditions that like to "hang out" with lupus and other autoimmune diseases. This can also be confusing. You are doing a really smart thing by getting educated on some of this stuff. It is a huge subject and it will take a long time and lots of reading to understand much of it . . . but it will really help you and your son make better use of the doctor's time.
I hope you'll keep us posted on his progress.
In His Grip
AlwaysRosie "We can't control the waves, but we can learn how to surf!!"
Co-Moderator - Lupus Forum
UCTD, Inflammatory Arthritis, Diverticulosis, (recent dx - Sjogrens, Crohn’s 4/08)
Clickable Links: Lupus Resources Lupous.Org Lupus Criteria (4 of 11) Lupus Chapter Locator