Spondyloarthropathies Flashcards
What are spondyloarthopathies?
A group of inflammatory joint disorders w/ similar symptoms - mainly pain & stiffness around the spine:
Ankylosing spondylitis
- Non-radiographic axial spondylitis - pain & stiffness around spine but no physical changes on x-ray
- Earlier stage of Ankylosing SpA. - Changes can be seen on MRI.
Reactive arthritis
Psoriatic arthritis
Enteropathic arthritis - associated w/ inflammatory bowl disease, Crohn’s disease & ulcerative colitis.
Undifferentiated - spondylarthritis where the cause is unknown.
NOTE: they are seronegative = negative for RhF…
What are the features of inflammatory back pain?
- Longer than 3 months
- Gradual onset - insidious
- Early morning stiffness
- Worse at rest
- Better w/ movement & exercise
- No radicular signs
- Usually at younger age
- Good response to NSAIDs
What is ankylosing spondylitis?
Sacroilitis (inflammation of sacroiliac joint) w/ pain, stiffness & structural changes to the spine.
Epidemiology of ankylosing spondylitis (risk factors)
Males> females (3 : 1)
Common 20-40 yrs
90% HLA B27 +ve in Europe - HLA B27 codes for a type of MHC class I molecule. - These are the molecules that present antigens to cytotoxic T cells.
Rare after 45 years.
Pathophysiology of ankylosing spondylitis
Interaction btw environmental pathogens & immune system.
- May be due to abnormal host immune response to intestinal microbiota.
- Th17 cells are in involved - play a role in mucosal immunity.
- Cytokines IL-22, IL-23, IL-17 & TNF-⍺ are produced in response
- IL-23 - produced by macrophages & dendritic cells in the intestinal submuscosa. IL-23 acts on T cells, neutrophils & mast cells to produce IL-17.
- IL-17 - large role in inflammation, causing sacroilitis & enthesitis.
- TNF-⍺ - produced by activated T cells & macrophages. Contributes to the inflammation.
- IL-22 - produced by T cells. Involved in causing new bone formation.
Syndesmophyte formation:
- due to ossification (new borne formation by osteoblasts)
- Fibroblasts replace destroyed cartilage in joint w/ fibrin
- Osteoblasts are activated & fibrin is ossified = back & neck more stiff.
- Severe disease = bones may fuse = bamboo spine (this is the ossification of the annulus fibrosis).
- Bone marrow oedema - fluid builds up in bone marrow
Presentation of ankylosing spondylitis: description of pain, MSK, extra-skeletal/ complications, joint distribution?
Description of pain:
- Lower back pain- gradual onset & for more than 3 months
- Worse in morning (at least 30 mins)
- improves on exercise but not rest
- Responds to NSAIDs
- Night pain- wakes patient in 2nd half of night
- Fatigue, fever, weight loss
- Osteoporosis
MSK:
- Sacroilitis - tender sacroiliac joints.
- Pain/Stiffness in buttock region - alternating.
- Loss of movement in spine - reduced lumbar lordosis, lateral flexion, anterior flexion & extension of spine
- Protruded abdomen + reduced chest expansion due to kyphosis- question mark posture = breathless.
- Kyphosis If untreated
Extra-skeletal complications:
- Aortic incompetance- reduced pulmonary function
- Apical lung fibrosis (rare)
- Atlanto-axial subluxation
- Achilles involvement (enthesitis)- inflammation of area where tendons / ligaments attach to bone e.g. Achilles tendon = soreness in heel. Plantar fasiitis = heel & arch pain.
- Acute uveitis= inflammation of eye
- psoriasis
- dactylitis
Joint distribution:
- Asymmetrical oligoarthritis
- Sacroiliac joints
- Spine
- Asymmetrical involvement of large or medium joints - usually shoulders or hips.
- Enthesitis is common at: iliac crests, gluteal & tibial tuberosities & heels.
Investigations for ankylosing spondylitis: Blood tests & examination
Blood tests:
- FBC - shows anaemia of chronic disease.
- ESR & CRP - high in active SpA
- RhF negative
- HLA B27 positive - useful for prognosis
Examination
- Schobers test- measuring length of back
- Sacroiliac squeeze test- applying pressure on anterior iliac spines whilst patient is supine.
- lateral flexion of spine
Radiological findings for ankylosing spondylitis
MRI:
- Sacroilitis & bone oedema = inflammation
- only seen on MRI!
- Note- view image on notes
X-ray:
- Lumbar spine squaring- calcification of adjacent intervertebral discs & new bone forms along anterior aspect of vertebral body- this reverses normal concavity & produces squared appearance
- Subchondral erosions- erosions that occur at corners of vertebral bodies
- Dagger sign- caused by ossification of infraspinous & supraspinouse ligament
- Sacroillitis- usually bilateral & symmetrical, loss of clarity of joint margins, erosions, joint space widening, sclerosis
- Syndesmophytes- due to ossification of longitudinal ligament= bamboo appearance
- Bone density- may be reduced, osteoporosis is a presentation
NOTE: view x-ray images on notes!
Management of ankylosing spondylitis
Conservative:
- Physiotherapy - mobilising exercises
- Occupational therpay
- Disease monitoring- BASDAI, BASFI, BASMI (Bath Ankylosing Spondylitis Disease Activity Index). FI = functional index; MI = metrology index.
Pharmacological:
1. NSAIDs e.g. Naproxen + PPI e.g Lansoprizole
2. Biologics e.g. TNF-⍺ inhibitors (Adalimumab, Etanercept)
3. Secukinumab (anti-IL-17 biologic) - used if NSAIDs or anti-TNFs haven’t worked. Only recommened if a discount has been negotiated.
4. Glucocorticoids injection - for persistent plantar fasciitis or enthesitis.
5. Oral glucocorticoids - for acite uveitis.
6. DMARDs for peripheral joints only -LIMITED USE e.g. sulfasalazine.
Surgical
- Arthroplasty - for secondary OA
- Spinal osteotomy - correct stoop
Epidemiology of psoriatic arthritis
Common in patients w/ psoriatic nail involvement
Men = women
25-40 years - but can vary
Juvenile forms exist
risk factor- HLA-B 27 positive
Pathophysiology of Psoriatic arthritis?
Local trauma causes dysreuglated immune response > local tissue destruction
Presentation if psoriatic arthritis?
Patterns of joint involvement:
1. Asymmetrical oligoarthritis(affecting 2-4 joints) - most common.
- Usually knees & small peripheral joints e.g. hands & toes.
2. DIP joint predominant
3. Symmetrical polyarthritis - just like RA - PIP, MCP, wrists, elbows & MTP of feet.
4. Spondylitis- inflammation of spine.
5. Arthritis mutilans - rare - affects DIP, PIP, MCP joints of hands & phalanges & metocarpal bones.
- Can also be seen in feet.
MSK features:
- Sacroilitis - often asymmetrical & asymptomatic.
- Dactylitis - swollen fingers & toes
- Enthesitis - inflammation at tendon/ligament insertion. MRI shows inflammatory changes where the plantar fascia inserts under the foot.
- Synovitis - joint pain, stiffness, swelling.
- Telescoping of digits - due to resorption of bone.
Extra-articular features:
- Psoriasis- might not be obvious, check scalp, naval & naval cleft
- Nail pitting
- Nail lifting
NOTE- family history of psoriasis is clinically important.
NOTE- view images on notes!
Investigations for psoriatic arthritis?
Blood tests:
- FBC- may show anemia
- ESR- high
- CRP- high
Radiological findings for psoriatic arthritis?
Radiological changes are asymmetrical & target small joints of hands & feet, particularly DIP joints
- Sacroilitis - asymmetrical - joint space narrowing, sclerosis & irregular margins. May be hard to see the joint.
- Erosions w/ proliferation of the adjacent bone - well-defined, peri-articular (surrounding joint) & asymmetric.
- Spondylitis - syndesmophytes - boney projections from spine. Bridging is less common.
- New bone formation at entheses e.g.Achilles tendon; plantar fascia to the calcaneum; & entheseal sites around pelvis.
- Pencil-in-cup deformities - progressive bone destruction & osteolysis. Bone destruction at the phalanx tip & new bone formation at the base of the adjacent phalax gives this appearance.
- Periostitis - inflammation of periosteum (connective tissue that surrounds bone) Looks ‘fluffy’ on x-ray.
NOTE- view x-ray images on notes!
Management of psoriatic arthritis
Conservative
- Physiotherapy
- Monitoring - DAS28, HAQ
Pharmacological:
- NSAIDs e.g. Naproxen, Diclofenac, Celecoxib + PPI e.g. Lansopizole
- DMARDs- Methotrexate, Sulfasalazine, Leflunomide, Ciclosporin + folic acid.
- Biologic DMARDs - anti-TNFs e.g. Adalimumab, Etanercept, Infliximab.
NOTE: Usekinumab & Apremilast - used when anti-TNFs are contra-indicated.
- JAK inhibitors - type of DMARD that tamp down overactive immune systems.
NOTE: in some patients, skin activity mirrors joint activity, so treat the skin, the joints improve.
What is reactive arthritis?
Inflammation of the joints, which is triggered by an infection from another part of the body e.g. gastrointestinal or genitourinary tract.
Aseptic = no joint infection.
Epidemiology of reactive arthritis
Males > females - 2:1 ratio
Main age group is 20-40 yrs
Associated w/ HLA B27. HLA = human leukocyte antigen.
Sexually acquired reactive arthritis = mainly young men (15:1)
Aetiology of reactive arthritis?
Bacterial causes of reactive arthritis include:
- Neisseria Gonorrhoea - most common cause in sexually active adults.
- Chlamydia trachomatis - will not show up in the gram stain due to poorly staining cell wall- causes RA in patients following episode of urethritis!
- Salmonella
- Shingella
- Yersinia Gonorrhoea
NOTE: can be caused by an STI, UTI or gastritis. There also viral causes but these do not have the SpA related symptoms.
Pathophysiology of reactive arthritis
T cells become activated by the bacterial fragments left over from the previous infection.
T cells attack components of joints because they think that those joints are bacteria which need to be attacked.
This can lead to inflammation of the joint or arthritis.
Presentation reactive arthritis
Pattern of joint tenderness/ pain involvement:
- Asymmetrical - 1 side of the body.
- Oligoarticular (2-4 joints)
- Larger weight bearing joints e.g. knees - most common + hip
Musculoskeletal features:
- Acute onset
- Synovitis - warm, red, swollen joint.
- Dactylitis
- Enthesitis - achilles tendonitis or plantar fasciitis.
- Sacroilitis (15-20%) - pain & stiffness in the sacroiliac region.
Extra-articular features:
- Symptoms often develop ~ 1-4 weeks after an infection
- Fatigue, low-grade fever, weight loss - systemic symptoms
- Conjunctivitis
- Uveitis - rare on first attack but found in 30% with chronic symptoms.
- Mouth ulcers
- Nail dystrophy w/ thickening of outer layer of skin.
- urethritis & dysuria! – inflammation of bladder & prostate may cause cystitis & prostatitis
(Reiter’s) Syndrome- triad of Arthritis, Conjunctivitis & Sterile Urethritis/ genitourinary infection = “Can’t See, Can’t pee, Can’t Climb a Tree”
Complications:
- Aortic incompetance
- Peripheral neuropathy
- Seizures
Investigations for reactive arthritis
Joint aspiration & synovial fluid analysis:
- Gram stain
- Culture - this should be negative in ReA- This rules out Sceptic Arthritis.
- Crystal analysis - rules out crystal arthropathies.
Blood tests
- FBC
- ESR & CRP = raised
- Antibodies against bacteria that you suspect
- RhF = negative
- U&E
- Culture blood
X-rays:
- Asymmetrical sacroillitis
- Periarticular osteoporosis
- Proliferative erosions - usually at entheses.
- Periostitis - especially at metatarsals, phalanges and pelvis.
- Calcaneal spurs - “fluffy” in appearance
- Syndesmophytes - course & asymmetrical.
Finding the cause:
- Cervical/penile swab - checks for STI
- Urinanalysis - Midstream urine sample - checks for UTI
- Stool sample
Management for reactive arthritis
- Rest
- Treat underlying infection w/ antibiotics if needed.
- NSAIDs e.g Naproxen, Celecoxib or Diclofenac + PPI
- Corticosteroid joint injections +/- systemic steroids
- Rarely DMARDs e.g. Methotrexate - for severe cases, recurrent arthritis
Differentials for reactive arthritis?
- Septic arthritis
- Crystal arthropathies
- Psoriatic arthritis
- Ankylosing spondylitis
Prognoses for reactive arthritis
Majority of ReA cases are mild.
Symptoms expected to be resolved for approx 50% of patients.
30%-50% of patients will develop chronic ReA.
Drugs for SpA
Apremilast:
- Active psoriatic arthritis in adults
- Can be used alone or w/ DMARDs
- Used before anti-TNFs are tried.
- Not very effective drug & usually used for patients who can’t have anti-TNF therapy.
- They have to have peripheral arthritis w/ 3 or more tender joints
AND their disease has not responded to 2 standard DMARDs (given either alone or in combination).
- side effect: GI disorders, upper respiratory tract infections
Ustekinumab:
- used to treat psoriatic arthritis & psoriasis
- can be used along or w/ methotrexate
- Only used when anti-TNFs are contraindicated
- Side effects: dental infections, upper respiratory tract infections, nausea or diarrhoea
