Rheumatology Flashcards
List 4 seronegative spondyloarthropathies
Ankylosing spondylitis
Psoriatic arthritis
Reactive arthritis
Enteropathic arthritis
Which seronegative spondyloarthropathies are more prevalent in males? (2)
Ankylosing spondylitis
Reactive arthritis
Which skin lesions can be seen in which seronegative spondyloarthropathies?
AS - rare to have skin lesions
Psoriatic arthritis - 100% psoriasis
Reactive arthritis - common - keratoderma blennorrhagica
Enteropathic arthritis - occasional - pyoderma, erythema nodosum
How common is the HLA-B27 marker in the seronegative spondyloarthropathies?
90% in AS
40% in PsA
80% in ReA
30% in EnA
In which seronegative spondyloarthropathies is sacroiliitis more common?
AS and ReA (compared to PsA and EnA)
What is the point of HLA-B27? (4) List disadvantages
- Not routine/diagnostic/confirmatory
- Cannot be used as a screening test for AS in the general population
- Sensitivity and specificity depends on racial/ethnic background of patient
- Does not help distinguish AS from other B-27 associated spondyloarthropathies
What postural changes can be seen in ankylosing spondylitis?
Decreased lumbar lordosis + increased thoracic kyphosis + increased cervical flexion = increased occiput to wall distance (>5 cm)
What is the most common extra-articular manifestation of ankylosing spondylitis?
Acute anterior uveitis - occurs relatively more commonly in HLA B-27 positive compared with those who lack the gene
In which seronegative spondyloarthropathies can aortic regurgitation occasionally occur?
AS
ReA
EnA
Rare in PsA
Describe the aetiology and pathophysiology of AS.
Relatively undetermined
Enthesitis thought to be source: inflammation –> osteopaenia –> erosion –> ossification –> osteoproliferation (syndesmophytes) which causes inflammatory low back pain
What is ankylosing spondylitis?
Chronic systemic inflammatory disorder of undetermined aetiology, usually beginning in early adulthood, primarily affecting the axial skeleton (but can peripheral arthritis and enthesitis) but can exhibit some extra-articular features (opthalmic, renal, gastro, cardiac, respiratory,neurologic)
What kind of pain is experienced in ankylosing spondylitis? (2)
- Inflammatory low back paine from syndesmophyte formation and/or buttock pain from sacroiliitis
- Inflammatory characteristic - nocturnal rest pain, early morning stiffness, relief with NSAIDs
Describe sacroiliitis pain. (2)
- Dull in character, difficult to localise and felt somewhere deep in the gluteal region
- May be unilateral or intermittent at first; however within a few months it generally becomes persistent and bilateral and the lower lumbar spine area also becomes painful
Describe the crystals seen in gout.
Monosodium urate –> needle-shaped, negatively birefringent (yellow)
Describe the crystals seen in pseudogout
calcium pyrophosphate dihydrate –> rhomboid-shaped, positively birefringent (blue)
Which tests can be used to measure spinal mobility in ankylosing spondylitis? (4)
- Modified Schober’s test - decreased forward flexion
- Lumbar side flexion: decreased
- Occiput-to-wall distance: increased
- Chest expansion: abnormal (<5 cm)
What investigations would you order in ankylosing spondylitis? (4)
- X-ray - appearance of radiographic abnormalities typically delayed - reactive sclerosis (Romanus lesion), squaring and erosions at the edge of the vertebral bodies to syndesmophyte formation and bony bridging i.e. ossification of outer fibres of annulus fibrosis - “bamboo spine”; interspinous ligament calcification ‘dagger spine’
- MRI - useful in EARLY DIAGNOSIS; good at detecting oedema or vascularised fibrous tissue, enthesitis of interspinous ligaments
- US - useful in detecting enthestisis
- Lab tests - ESR/CRP - only elevated in 50-70% of AS patients; HLA-B27 (90% of those with AS have this marker; but not all those with this marker will develop AS)
How is AS managed? (3)
Symptom management
- education and exercise
- NSAIDs
- TNF inhibitors - for patients with inadequate responst to NSAIDs
What is the first line therapy of Ankylosing Spondylitis?
NSAIDs
In which type of spondyloarthropathy should NSAIDs be used in caution?
Enteropathic
How is psoriatic arthritis managed? (3)
- Treat skin lesions (e.g. steroid cream, salicylic and/or retinoic acid, tar, UV light)
- NSAIDs or intra-articular steroids
- DMARDs, biologic therapies to minimise erosive disease
Which dermatological features are diagnostic of ReA?
Keratoderma blenorrhagicum (hyperkeratotic skin lesions of palms and soles) and balanitis circinata (small, shallow, painless ulcers of glans penis and urethral meatus)
How is ReA investigated? (3)
CLINICAL PLUS LABORATORY DIAGNOSIS
- Bloodwork - normocytic, normochromic anaemia and leukocytosis
- Sterile cultures
- Serology: HLA-B27
List 2 primary causes of hyperuricaemia.
- Mostly due to idiopathic renal underexcretion
2. Idiopathic overproduction or abnormal enzyme production/function
List 3 secondary causes of hyperuricaemia.
- Dietary excess
- Underexcretion - renal failure, drugs, systemic conditions
- Overproduction - increased nucleic acid turnover states (e.g. malignancy, post-chemotherapy)
How is gout investigated? (2)
- Joint aspirate: >90% of joint aspirates show crystals of monosodium urate (negatively birefringent, needle-shaped)
- X-rays may show tophi as soft tissue swelling, punched-out lesions
How is gout managed acutely? (3)
- High dose NSAIDs: indomethacin for up to 7 days
- Colchicine (SE: gastrointestinal effects)
- +/- intra-articular steroids where the above 2 options are contraindicated (i.e. in moderate to severe renal impairment)
How is chronic gout managed? (4)
- Diet- avoid foods with high purine content (e.g. visceral meats - liver and kidney, sardines, shellfish, beans, peas)
- Manage weight
- Limit alcohol intake
- Medical - to prevent recurrence
- Xanthine oxidase inhibitors reduce the production of uric acid (e.g. Allopurinol)
- uricosuric drugs increases renal uric acid excretion (e.g. Probenecid)
Allopurinol to be given only in proven recurrence (more than 2 documented attacks) - start approx. 4/52 post-attack; should be continued during acute episodes once already started
Describe the aetiology and pathophysiology of pseudogout.
Acute inflammatory arthritis due to phagocytosis of IgG-coated calcium pyrophosphate dihydrate (CPPD) crystals by neutrophils and subsequent release of inflammatory mediators within joint space
Describe the disease pattern of pseudogout (2)
- More frequently polyarticular - knee, polyarticular wrist, hand (MCP), foot (1st MTP), hip
- Slower in onset in comparison to gout
How is pseudogout investigated? (2)
- Joint aspiration - CPPD crystals present in 60% of patients
- X-ray - chondrocalcinosis (visible calcification of cartilage) in 75%: radiodensities in fibrocartilaginous structures or linear radiodensities in hyaline articular cartilage
How is pseudogout treated? (3)
- Joint aspiration, rest and protection
- NSAIDs
- Intra-articular or oral steroids to relieve inflammation
PROPHYLACTIC COLCHICINE PO CONTROVERSIAL
Which joints can be affected in rheumatoid arthritis?
Wrist MCP PIP Elbow Shoulder HIp, knee, ankle
DIP SPARED
Describe the characteristic pattern of symptoms seen in rheumatoid arthritis (3)
- Symmetric joint involvement and tenosynovitis - swelling and tenderness, but initially involves small joints of hands and feet (persisting for at least 6 weeks - diagnostic)
- Morning stiffness greater than 1 hour, improves with use and aggravated by rest
- Constitutional symptoms - profound fatigue; rarely myalgia or weight loss
List 4 hand and finger joint deformities that can be seen in rheumatoid arthritis.
- Swan neck deformity - hyperextension of PIP joint with flexion of DIP joint
- Boutonniere’s deformity - flexion of PIP joint with hyperextension of DIP
- Ulnar deviation of MCP
- Radial deviation of wrist joint
List three toe joint deformities that can be seen in rheumatoid arthritis.
- Claw toe - hyperextension of MTP and flexion of PIP and DIP joints
- Hammer toe - abnormal flexion of PIP
- Mallet toe - flexion posture of DIP
Describe the epidemiology of rheumatoid arthritis.
F>M
Can occur in all age groups, but increases in incidence with advancing age, with a peak between the fourth and sixth decades
Genetic predisposition: HLA-DR4/DR1
What investigations would you order in rheumatoid arthritis?
- Bloodwork
- RF sensitive 80% but not specific
- anti - CCP - sensitive 80%
- HB - decreased (anaemia of chronic disease)
- increased platelets
- elevated ESR,CRP - not specific - X-ray
- can be normal at onset however essential for monitoring
- soft tissue swelling -> osteopenia -> joint space narrowing -> erosions -> joint destruction
How is rheumatoid arthritis managed?
- Non-pharmacological: weight control, patient education and self-management programmes, thermotherapy, appropriate foot care etc.
- Pharmacological:
Simple analgesics - pain relief
NSAIDs - pain relief
Corticosteroids - local/intra-articular or systemic
DMARD - consider if several swollen joints, MTX gold standard - Surgery indicated for structural joint damage
- joint replacement
- arthrodesis - wrist, thumb, ankle, C-spine
- excision - head of radius, metatarsal heads