Abstract
We describe the case of a Japanese girl who suffered from both Behçet's disease (BD) and bilateral sacroiliitis. This patient was diagnosed with BD at 8 years of age, and began to complain of buttock pain when she was 10 years old. X-rays of her pelvis showed bilateral grade 3 sacroiliitis, and bone scintigraphy showed an increased uptake in the sacroiliac joints. Movements of the spine and chest expansion were not restricted. HLA typing was positive for B44 and DR4, but negative for B27. The patient was not diagnosed as having seronegative spondyloarthropathy. This case indicates that erosive sacroiliitis is an intrinsic condition of BD.