Orthopaedic complications of Lyme disease in children.

Lyme disease is transmitted by the tick Ixodes dammini ("deer tick") or a related ixodid tick. Early diagnosis of children with Lyme disease is difficult because the bite of the ixodid tick often goes unnoticed. Furthermore, erythema chronicum migrans, the characteristic rash of the disease, occurs in less than 50% of cases. However, an awareness of orthopaedic complications of Lyme disease may facilitate an early diagnosis of this disease. Orthopaedic complications of Lyme disease include those which are oligoarticular in nature. Brief intermittent attacks of swelling and pain in one or more joints--primarily large ones--is the pattern of disease most frequently presented. The knee is the joint most commonly affected. In most cases, pain is not severe enough to debilitate the patient or prevent weight-bearing activity. An elevated sedimentation rate is the only consistently abnormal routine laboratory finding in Lyme disease. The only radiographic abnormalities noted in children are effusion and osteopenia. However, the radiograph of a patient known to have Lyme disease may not show any abnormalities at all. Lyme disease shares symptoms in common with septic arthritis and juvenile rheumatoid arthritis. Whenever a distinction between Lyme arthritis and septic arthritis is difficult to make, treatment should be directed at septic arthritis while serological tests for Lyme disease are pending. The physician should consider Lyme disease to be a possible diagnosis of any patient with arthritis and a history of rash or fever, idiopathic neurological disease, or a cardiac conduction defect--especially if there is a history of possible exposure to the carrier tick.(ABSTRACT TRUNCATED AT 250 WORDS)