It's never lupus!
Have them check your ANCA and specifically look for an auto-immune disorder called Wegener's Gramulatosis (I probably misspelled the last word). My wife has this disorder and I've seen similar rashes on her before.
Highest Weight: 564 / Post Band Pre DS Weight: 508 / Surgey Date Weight: 449
Current Weight: 209 / Goal Weight: 150 (BMI of 25).