Ankylosing Spondylitis

Symptoms  Chronic systemic inflammatory disease involving axial skeleton of younger pts  Develops in second/third decade  Typically dull aching pain of insidious onset in lower lumber/ buttock region  Early morning stiffness(ems) and nocturnal pain

Symptoms  Stiffness improves with exercises and recurs after periods of inactivity  Some pts present with painful hips, shoulders, asymmetrical arthritis of lower limbs prior to spinal involvement  Cervical and thoracic pain and stiffness is frequent

Symptoms  Enthesitis incl chest pain is common- aggravated by manoeuvres increasing intra-thoracic pressure (eg coughing)  Peripheral joints: shoulders, hips, costovertebral, costosternal, manubriosternal, sternoclavicular joints commonly symptomatic at presentation  M > F. 2-3.

Symtoms and presentation  Males: spine and pelvis more frequently involved with some involvement of hips, shoulders and chest wall. Tend to have a more severe disease than females  Females: pelvis, hips, knees, and wrists with less severe inv of the spine  Enthesitis-inflammation of ligament and tendon typical in seronegative arthritis. Eg achilles tendonitis, illiac crest pain, chest wall pain-from inv of costochondral, manubriosternal and sternoclavicular joints

HLA-B27  B27 +ve in 90-95% of AS.  Lower prevalence of B27 in african/african-american population associated with a lower prevalence of AS in these populations  B27 +ve individuals have a 2-5% chance of developing AS  Male sex, B27+ve, FHx of AS + frequent GI infections are all RFs for developing AS

Pathogenesis  ?development in genetically predisposed individuals, triggered by an environmental factor eg gastro-intestinal infection  Reactive arthritis has a similar pathogenesis whereby chlamydia trachomatis, yersinia enterocolitica, shigella flexneri, campylobactor jejunii, salmonella typhymurium have been implicated.

Pathogenesis  B27 +ve rats in a germ-free environment do not develop AS  There is a high incidence of GI mucosal inflammation (both symptomatic and asymptomatic), this raises the possibility that the gut, with breakdown of the mucosal lining is a triggering event.

Pathogenesis  Activated T-cells and macrophages found at sites of inflammation with expression of IL-1β, tnf-α and IF-γ. These inflammatory cytokines cause erosion of cortical bone, new bone formation and loss of bone mass

Associated features  Extra-articular symptoms eg acute anterior uveitis.  Inflammatory bowel disease and/or psoriases may be present  AS associated with CD/UC occurs in 5- 10% of individuals  Asymptomatic GI inflammation present in 25-49% of AS

Associated features  50-60% of AS have microscopic inflammatory lesions at any one time  Uveitis occurs in 25-40%  Osteoporoses is a common feature-look out for this  Less frequent-aortic incompetence, cardiac conduction anomalies, progressive, b/l apical cavitation/fibroses  Other spondyloarthropathies-ReA, PsA Enteropathic arthritis commoner in relatives

Examination  B/L sacro-illiac joint tenderness (febere manoeuvre)  Peripheral joint synovitis-asymmetric, oligoarticular pattern.  Dactylitis of fingers and/or toes  Enthesopathy-thickened achilles tendon, planter fascitis, chest wall tenderness etc

Examination  Advanced disease; changes in posture- flattening of normal lumber lordoses, thoracic kyphoses may be exaggerated.  C-spine-limitation in ROM with fusion in hyper-flexion

Presentation  Chronic low back pain-usually as a teenager  Tend to remain active as way to ease pain and stiffness  Back pain tends to become more progressive, symptomatic and severe-look for inflammatory back pain symptomatology  Look for assoc chest wall tenderness, heel pain, buttock pain.

Presentation  Rarely may present with acute anterior uveitis  Look for other features of extra-axial involvement which would aid diagnoses- asymmetrical oligoarthritis, enthesopathy.  Sacro-illeitis; present with pain radiating to buttock and radiating to upper posterior thighs. Usually U/L, intermittent or alternate from one to other side and eventually becomes B/L and persistent

Examination  Chest expansion, SIJ  Typical spinal ankyloses occurs after ~ 10yrs  Osteoporoses more likely in severe advanced, long-standing AS esp in pts with immobile spine.  Rigid osteoporotic spine susceptible to vertebral fractures-prophylactic treatment

Diagnoses + Investigations  Based on clinical/blood test and radiological findings  Symptoms of inflammatory back pain  Family history  Extra-articular lesions  B/L sacro-illeitis on XR or MRI  MRI-STIR sequences show up inflammation with bone marrow oedema and enthesopathy

Diagnoses and investigations  HLA B-27: in whom hx and examination is suggestive of a sero-negative spodyloarthropathy but have normal XRs  Should not be used as a routine, diagnostic, confirmatory or screening test.  Positive B-27 in the presence of non- inflammatory back pain with –ve XRs does not confirm diagnoses and up to 8% fo normal pop are +ve. Higher in normal relatives.  ↑esr/crp in 70% of AS, but no clear correlation with disease activity. Associated with peripheral arthritis rather than axial arthritis

Management  Combination of non-pharmocologic and pharmocological therapy depending on disease stage and symptoms  Patient education essential-life long programme of exercise, use of individual, and group therapy as well as self-help groups  Functional disability in AS progresses more rapidly in smokers and less so in those with better social support and reg exercises

Management  NSAIDs-essential  DMARDs-not recommended for axial disease, however SASP found to be useful in periopheral arthritis  Steroids-oral or parenteral not recommended  Anti TNF-all three effective in AS in pts with persistently high BASDAI. No need to use MTX with anti-tnf prior to commencing anti-tnf

Surgery  Rare  Hip arthroplasty-structuarl damage causing refractory pain  Corrective spinal osteotomy. Fusion procedures in patients with segmental instability may be indicated.

Prognoses  Depends on stage at diagnoses  Initiation of effective therarpy  Worse in smokers, low socio-economic class  Worse in pts poorly compliant with exercises  Males worse than females

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