Giant Iliopsoas Bursitis in Systemic Juvenile Idiopathic Arthritis

Abstract
A 4‐year‐old boy with systemic juvenile idiopathic arthritis (sJIA) relapsed while on tacrolimus and tocilizumab (TCZ). He presented with right groin pain and claudication. The patient had mild tenderness and restricted range of motion in his right hip joint on physical examination. Furthermore, no mass was palpable. Laboratory findings revealed a highly elevated level of serum matrix metalloproteinase‐3 (MMP‐3; 551 ng/dL).