What are the advanced symptoms of Lyme disease?

In the United States, approximately 60 percent of untreated Lyme disease patients will develop intermittent episodes of joint pain and swelling, months to years after the infecting tick bite. The most common presentation is a single involved knee, but both large and small joints may be affected and usually only one or two joints at a time.

Over time, the frequency and severity of attacks can decline, and, on average, the proportion of patients with recurrent attacks declines by 10-20 percent annually.

Approximately 10 percent of untreated patients may develop chronic arthritis, defined as one year or more of continuous joint inflammation. Lyme arthritis patients experience prominent cellular and humoral immune responses.

Some patients with Lyme arthritis experience no resolution of symptoms even after long-term antibiotic therapy, and are termed as having antibiotic treatment-resistant Lyme arthritis.