I had lots of negative tests. Some people go through years of negative tests. These are very difficult diseases, in most cases, to diagnose.
UCTD is not really a diagnosis...it is more of a transitory stage which usually develops into something else but not always.
To get a diagnosis of mctd you will eventually have a positive result on anti rnp antibodies. My docs tested me for various things but this did not show up for 13 months. Actually I had blood anomalies for 15 years before I got symptomatic so take you pick on how long it took.
If you say the neurologist tested one arm....how? Biopsy? Strength test? Myositis is usually symmetrical.
MCTD (lupus, scleroderma, polymyositis). Diagnosed 2005. Kidney, liver, GI tract, dysphagia, raynauds, Barretts esophagus, quadriplegic in 2005. Recovered and now active in skiing, tai, chi, hiking, golf. Meds: prednisone 2.5mg, imuran 25mg, amlodipine, benazapril, omeprazole, potassium, folic acid, vitamins, maxide and various supplements and vitamins.
Remain optimistic and you can overcome the odds.