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Ankylosing Spondylitis (AS)

Last updated 13.02.13

 

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Index

 

Definition

-  Idiopathic chronic progressive seronegative arthritis associated with articular & para-articular inflammation frequently resulting in bony ankylosis

 

Features

-  0.1–0.2% prevelance

-  Male 4-10:1 female, mean age 26 yrs

-  Family Hx

-  HLA-B27 in 90-95%

 

Assocaited S/S

-  Lower back pain from sacroiliitis most common presenting complaint

-  Centred over sacrum

-  Radiates to buttocks or legs

-  Morning stiffness

-  Back pain waking from sleep

-  Schobers test: reduced

-  Typically axial skeleton

-  Sacroiliac (most common)

-  Spinal facet joints: lumbosacral, thoracolumbar

-  Restrited chest expansion: diaphragmatic breathings

-  Cervical spine ankylosis: restriced head movements

-  Paravertebral soft tissues

-  Peripheral arthritis: chronic disease

-  Hip joint most common

-  30% glenoumeral or knee

-  Iritis

-  Anterior Uveitis 20% pts

-  Usually precedes spinal S/S

-  Pulmonary

-  Restrictive lung disease: chest expansion

-  Apical fibrosis, cavitation

-  Cardiac

-  Aortic regurgitation: aortitis

-  Cardiomyopathy

-  Pericarditis

-  Conduction defects

-  Amyloidosis (rare)

 

Dx Rome Criteria

-  Bilateral sacroiliitis & 1+ of

-  Lower back pain & stiffness >3/12

-  Pain or stiffness in thoracic region

-  Limited lumbar motion

-  Limited chest expansion

-  Hx of iritis or sequelae

 

DDx

-  RA

-  Both show chronic synovitis

-  No pannus formation

-  RF: -ve (+ve in RA)

-  Reiters disease, psoriasis, IBD, gout

 

Ix

-  Plain film X-Ray

-  Effected joints

-  50% abnormal

-  Sacroilititis

-  Bamboo spine, Poker spine

-  Pubic symphysis, manubrosternal, acromioclavicular, sternoclavicular

-  +/- MRI

-  Bone marrow oedema

-  Romanus lesions (squaring of vertebral bodies)

-  Syndesmophyte formation

-  Ankylosis

-  Erosions

-  FBE

-  Mild leukocytosis

-  Anaemia of chronic disease

-  ESR/CRP: elevated in acute phase

-  HLA-B27: 90-95% pts

-  ANA & RF -ve

-  Spirometry: restrictive lung disease

 

Sacroiliitis

 

Bamboo Spine

 

Mx

-  Life long regular exercise

-  Chest exercises

-  Spinal mobility

-  Analgesia: NSAIDs

-  TNF-alpa antagonists

-  Corrective joint surgery as required