Clinical Features of third stage of Lyme disease
Clinical manifestations of the third stage (late disease) of Lyme disease
The third stage of Lyme disease occurs in 10% of untreated patients and represents persistent infection due to B. burgdorferi , which has mechanisms that enable it to evade the immune system. This stage usually involves episodic attacks of an asymmetric oligoarticular arthritis affecting the large joints (knee 80% of time). Historically, 60% to 80% of patients with ECM who were not treated with antibiotics would develop arthritis. Over time the arthritic attacks typically resolve. In <10% of patients, the arthritis becomes more persistent and chronic usually affecting the knee. Fatigue frequently accompanies the arthritis episodes, but in general fever and other systemic symptoms do not. Synovial fluid is inflammatory (average white blood cell count is 25,000/mm 3 with neutrophil predominance). In Europe a progressive skin lesion, acrodermatitis chronica atrophicans, is the most common late manifestation. The lesions are red or bluish-red swellings, typically on the extensor surfaces of extremities, which eventually become atrophic. Chronic nervous system involvement may occur in the third stage but is rare. Manifestations include a chronic severe encephalomyelitis, primarily described in Europe. Stroke-like presentations, a mild sensory polyneuropathy, and mild encephalopathy have also been described.