A cohort of children with Lyme arthritis was used to evaluate the clin
ical and serologic profile of the disease. During a 42-month period (J
une 1989 to December 1991), 44 patients (13 girls and 31 boys, ages 4-
18 years) were included and followed for 6-36 months. Inclusion requir
ed the presence of arthritis, as well as positive serology. Thirty-fou
r children with juvenile rheumatoid arthritis or spondyloarthropathy w
ere used as a serologic comparison group. Five different patterns of a
rthritis were found. Preceding erythema migrans was seen in seven chil
dren. Antinuclear antibodies were positive in 30% of the patients. Thr
ee treatments were used and selected according to physician preference
, patient age, and presence of extraarticular disease: amoxicillin, do
xycycline, and ceftriaxone. Articular disease reached complete resolut
ion in all patients within 2-12 weeks. Lyme arthritis in children may
mimic other pediatric arthritides. Prognosis for children with clearly
defined