I should mention that no 'bulls eye mark was ever found on me.
Most but not all patients with Lyme disease will develop the characteristic bulls-eye rash.
The EM rash, which does not occur in all cases, is considered sufficient to establish a diagnosis of Lyme disease even when serologic blood tests are negative.
Lyme disease is diagnosed clinically based on symptoms, objective physical findings (such as erythema migrans, facial palsy, or arthritis), a history of possible exposure to infected ticks, as well as serological blood tests.
Most but not all patients with Lyme disease will develop the characteristic bulls-eye rash.
The EM rash, which does not occur in all cases, is considered sufficient to establish a diagnosis of Lyme disease even when serologic blood tests are negative.
After several months, untreated or inadequately treated patients may go on to develop severe and chronic symptoms that affect many parts of the body, including the brain, nerves, eyes, joints and heart.
Lyme arthritis usually affects the knees. In a minority of patients arthritis can occur in other joints, including the ankles, elbows, wrist, hips, and shoulders. Pain is often mild or moderate, usually with swelling at the involved joint.
So you have to recollect the diagnosis how it was done 20 years ago and do you have any other symptoms other than arthritis presently?
As you responded to Pencillin you can conclude that it was Lyme's disease.
Present complication has to be diagnosed between long term effects of Lyme or RA.
Go for Rheumatoid Factor, RF test, and see an Orthopaedician for clinically testing other major signs of RA. If you do not have RA signs and you also have some other associated organs involved along with your joints/arthritis you can conclude it to be long term complication of Lyme's.
JRA would never respond to antibiotics.
Take care and come back to us on further queries!