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Friday, June 6, 2008
My knee hurts and is swollen, I did nothing to injure it. Is it Lyme?
Lyme disease frequently presents itself with a single painful joint. It is nice when it is large joint, such as the knee and an effusion (water on the knee) is present. The fluid can be withdrawn by a needle and tested. A positive test for Lyme will only be obtained if the doctors knows what test to order. The test that is accurate is not FDA approved and the standard tests are virtually worthless. The fluid must be sent for Lyme Western Blot antibodies and or a C6 peptide ELISA test for Lyme antibody. The Lyme germ will not be in the fluid, unless the doctor is very lucky. The Lyme bacteria lives in the cartilage and synovial lining of the joint. A culture will be negative. A PCR test for Lyme DNA will be negative. This is a great test but it only works if the specimen contains the actual bacteria. This is a test that most doctors order because they think it is reliable. The bacteria are not in the fluid so it will consistently be negative. The fluid shows an acute inflammatory response. Tests for the usual rheumatological causes of this sort of arthritis will be negative. The doctor will scratch his head. A wrong diagnosis will be made. . This sort of inflammatory arthritis of a single joint could be: gout, rheumatoid arthritis, another bacterial infection, Reiter's syndrome, reactive arthritis of various sorts, psoriatric arthritis and others. A blood test for Lyme may be ordered. But the usual ELISA/Western Blot two step will be negative in the vast majority of cases. These patients frequently do not have a lot of other Lyme symptoms and are in a fairly early stage which is easy to cure. It is unfortunate that most patients will be diagnosed and treated based on algorithms which don't work. These patients can be easy or vary hard, depending on the treating doctor's understanding of the issues outlined here. Test books need to be updated so that physicians will get this one right. When the disease is missed at this stage there may be hell to pay down the road.