Table 2.

Pediatric clinical presentations for LA, septic arthritis, ReA, and JIA

PRESENTATION OR VARIABLELASEPTIC ARTHRITISReANONSYSTEMIC JIA
EffusionCommon (warmth)Common (warmth and erythema)Common (warmth)Common (warmth and erythema)
No. of joints involvedMonoarticular (63%)
≥ 2 Active joints (27%)
Monoarticular (80% to 90%)Oligoarticular
Monoarticular
Oligoarticular (50% to 60%)
Polyarticular (15% to 25%)
Most commonly involved jointsKnee (> 90%)
Ankle (25%)
Knee and ankle (56%)
Knee (> 50% in adults)
Hip (15% in adults)
Hip
Knee
Ankle
Knee
Wrist
Ankle
Refusal or inability to weight bearUncommonCommonCommonUncommon
Pain with passive range of motionMildSevereModerate to severeMild to moderate
Fever (> 38.5°C)UncommonCommonUncommonUncommon
RashMight have remote history; rash not concurrent with arthritis (erythema migrans)Common (localized redness of affected joint)Common (erythema nodosum, keratoderma blennorrhagicum)Uncommon
  • JIA—juvenile idiopathic arthritis, LA—Lyme arthritis, ReA—reactive arthritis.

    Data from Hannu,2 Arvikar and Steere,3 Shirtliff and Mader,4 Shapiro et al,5 and Gerber et al.6