Most auto-immune diseases are diagnosed by symptoms rather than by blood tests, including Lupus. Check out the symptoms used to diagnose Lupus in the link below, Diagnosing Lupus.
Have you considered Sjogren's Syndrome?
Lupus & Sjogren's are both handled by rheumatologists - so I would hope that if it were either of those your current Dr could diagnose.
You say you use steroids for headaches -- do the steroids make your hands feel better?
Lynnwood, Lupus & Sjogren's Moderator, Dx: 2002DIAGNOSING LUPUS & HW's LUPUS 101
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