Hi undiagnosed,
The rheumatologist has probably ordered the ELISA and the Western blot. Of the two, the Western is the more accurate.
Only a non-Lyme Literate doctor would say that the test will
definitelyshow Lyme disease!!! Lyme needs to be diagnosed clinically with a careful look at your history and symptoms and using the tests just as a guide. The tests look for the antibodies for the disease, but the nature of the disease itself is that it suppresses the immune system so the antibodies may not be there at the moment.
You really need to see a Lyme Literate Doctor to get a good diagnosis and thorough, effective treatment.
Let us know if you need help finding one.