Joint and bone involvement in Swedish patients with Ixodes ricinus-borne Borrelia infection.

The presence of signs of joint involvement was investigated in 231 patients with erythema chronicum migrans Afzelius (ECMA), in 50 patients with acrodermatitis chronica atrophicans (ACA), in four patients with spirochete-induced facial palsy and in one patient with pericarditis and serologic evidence of Borrelia spirochetal infection. Only one of 16 untreated patients with ECMA developed arthritis. The patient with pericarditis had suffered from arthritis for 2 months when the cardiac symptoms developed. Thirteen of the patients with ACA had luxations/subluxations of small joints in the hands or feet and/or arthritis in large joints. In four of the patients with ACA, periosteal thickening of bones was found. The results indicate that joint abnormalities are not uncommon in patients with ACA. However, arthritis during the first year of tick-borne spirochetal infection was less common in Sweden than has been reported among patients with Lyme disease in the United States.