RESUMEN
Sacroiliitis is a prototyical feature of the seronegative spondyloarthropathies. It has been reported rarely in patients with systemic lupus erythematosus. We report a case of bilateral sacroiliitis in a 26 year-old female who presented 5 out of 11 ARA criteria for systemic lupus erythematosus. She complained of right low back pain since 1 week after delivery. Plain roentgenogram, computed tomogram and magnetic resonance imaging revealed no evidence of subluxation or pyogenic infection that may be possibly related to delivery, but bilateral sacroiliitis especially more severe in the right side that showed concordantly increased uptake on bone scan. Also she had neither HLA DR-3 nor B-27 antigens and had no other clinical findings of limitation of motion of spine and chest expansion, which suggest that there is a less likelihood of coexistent ankylosing spondylitis. In this case, we suggested that sacroiliitis may be a infrequent manifestation of systemic lupus erythematosus.