RESUMO
Ankylosing spondylitis (AS) is a heterogeneous and systemic rheumatic disorder of unknown cause that is characterized by inflammation of the spine and sacroiliac joints. It is more common in young men. The disease is frequently associated with peripheral arthritis, enthesitis, anterior uveitis and high prevalence of HLA-B27. In some patients with AS, peripheral arthritis can occurs earlier than spinal symptom and more commonly affects the lower extremities than the upper extremities. Unlike men, women appear to have milder or atypical AS, especially at juvenile onset. However, involvement of the hands is extremely rare. Juvenile AS, defined as onset of disease prior to the age of 16 years, is considered a pediatric form of AS. On the other hand, although the atlantoaxial subluxation has been infrequently observed in patients with ankylosing spondylitis, atlantoaxial bony ankylosis has not been described in the literature. We describe a 23-year-old woman with juvenile AS who developed the atlantoaxial bony ankylosis and the hand involvement mimicking rheumatoid arthritis. Besides the rheumatoid-like hands and atlantoaxial bony ankylosis, she has shown the typical features of spondyloarthrpathy such as bilateral sacroiliitis, inflammatory spinal pain, enthesitis, severe arthritis of both hip joints, and positive HLA-B27 test.