Which presentation is primarily axial in Ankylosing Spondylitis?

Which presentation is primarily axial in Ankylosing Spondylitis?

• A. Peripheral
• B. Both
• C. None
• D. Axial

Answer: (D)

Ankylosing spondylitis most characteristically affects the axial skeleton, especially the spine and sacroiliac joints. The hallmark inflammatory back pain pattern—insidious onset, improvement with activity, worsening at night, and progressive stiffness leading to reduced spinal mobility—reflects this axial involvement and can progress to limited chest expansion or fusion of the spine. Peripheral arthritis can occur, but it is not the primary pattern in AS. Thus, the presentation that is primarily axial is involvement of the spine and sacroiliac joints.

Ankylosing spondylitis most characteristically affects the axial skeleton, especially the spine and sacroiliac joints. The hallmark inflammatory back pain pattern—insidious onset, improvement with activity, worsening at night, and progressive stiffness leading to reduced spinal mobility—reflects this axial involvement and can progress to limited chest expansion or fusion of the spine. Peripheral arthritis can occur, but it is not the primary pattern in AS. Thus, the presentation that is primarily axial is involvement of the spine and sacroiliac joints.