Ankylosing Spondylitis

Dept of Medicine, ACMS

Pathology

• Sacroiliitis

• Spine

• Enthesitis

Clinical manifestations

• Dull low back pain

• Bony tenderness

• Arthritis

• Neck pain and stiffness

• Juvenile variant

On examination

• Decreased spinal mobility– Modified schober’s test– Chest expansion

• Pain in sacroiliac joint

• Pain in hips and shoulder

Progression of the disease

Posture changes

• Loss of lumbar lardosis

• Buttock atrophy

• Accentuated thoracic kyphosis

• Forward flexion of the neck

• Flexion of hip with compensatory flexion of kness

MEASURE OF DISEASE PROGRESSION

AS

Parameters •Loss of height

•Limitation of chest expansion

•Spinal flexion

•Occiput-wall distance

•Floor gaze angle

Poor prognostic markers & complications

• Early onset disease

• Early hip involvement

• Smoking

• Spinal fractures– Lower cervical spine– Neural damage

Extraarticular manifestations

Common • Anterior uveitis• IBD• Psoriasis• AR• Complete heart block

Rare • Cauda equina syndrome• Upper lobe fibrosis• Retroperitoneal fibrosis• Amylodosis

Measurement of disease activity

• BASDAI

• BASFI

• Cause of death– Spinal trauma– AR– Respiratory failure

Lab

• HLA-B27

• ESR/CRP

• Anemia

• ALP

• Spiromerty

Radiology

Sacroiliac joint In AS

Radiology

Cervical spine Lumbar spine

ASAS criteria for classification of axial SpA

SI on imaging plus ≥1 SpA feature HLA-B27 plus ≥2 other SpA features

Sacroilitis on imaging SpA features

Active inflammation on MRI highly suggestive of SpA associated SI

Inflammatory back pain

Arthritis

Enthesitis

And/or Anterior uveitis

Definite radiographic sacroiliitis according to modified New York criteria

Dactylitis

Psoriasis

Crohn’s disease or UC

Good response to NSAIDs

Family history of SpA

HLA-B27

Elevated CRP