Rheumatology Flashcards
What is arthritis?
Disease of the joints
What are the 2 types of arthritis?
- Degenerative
- Osteoarthritis
- Inflammatory
- Infection —> septic
- Crystal —> gout, pseudo-gout
- Autoimmune —> rheumatoid, seronegative, SLE
What is osteoarthritis?
Arthritis caused by articular cartilage loss
- Risks —> elderly
—> previous joint trauma
—> lots of manual labour
- Onset —> gradual
How is osteoarthritis diagnosed? (3)
- Clinical:
- Pain —> worse with activity
- Crepitus —> cracking sound with movement
- Enlargement
- Limited range of motion
- Specific joints —> DIP, PIP, CMC, MTP etc.
- Blood:
- X-ray:
- Joint space narrowed —> articular cartilage loss
- Subchondral bony sclerosis —> inc whiteness
- Osteophytes —> bony lumps
- Subchondral cysts —> fluid filled space
Which joints are typically affected by osteoarthritis? (3)
Hand:
1. DIP = Distal InterPhalangeal
—> Heberden’s nodes
2. PIP = Proximal InterPhalangeal
—> Bouchard’s nodes
3. First CMC = CarpoMetaCarpal of thumb
Spine
Limbs (weight-bearing):
4. Knees
5. Hips
6. First MTP = MetaTarsoPhalangeal
- base of big toe
What are the 5 clinical signs of inflammatory arthritis?
- Rubor - red
- Dolor - pain
- Calor - heat
- Tumor - swelling
- Loss of function
What are the 3 causes of inflammatory arthritis?
- Infection - secondary, non-sterile
—> septic
—> TB - Crystal - secondary, sterile
—> gout
—> pseudo-gout - Autoimmune - primary, sterile
—> rheumatoid
—> seronegative
—> SLE
What are the 2 types of inflammatory arthritis via infection?
- Septic arthritis
- Tuberculosis
What are the 2 types of inflammatory crystal arthritis?
- Gout
- Pseudo-gout
What are the 3 types of inflammatory autoimmune arthritis?
- Rheumatoid arthritis
- Seronegative arthritis
- SLE = Systemic Lupus Erythematous (Lupus)
What is septic arthritis?
Arthritis cause by a bacterial infection
- Usually spread via blood
- Medical Emergency —> can destroy joint
- Bacteria —> staphylococcus aureus
—> streptococci
—> gonococcus
- Risks —> immunosuppressed
—> pre-existing joint damage
—> IVDU (IntraVenous Drug Use) - Onset —> acute
How is septic arthritis diagnosed? (3)
- Clinical:
- Inflammation —> red, hot, painful, swollen
- Monoarthritis - except gonococcal (poly)
- Fever —> systemically unwell
- Blood:
- WCC high
- PLT high/normal
- ESR high/normal
- CRP high
- Joint Aspiration:
- MC&S —> gram stain
How is septic arthritis treated? (2)
- Surgical washout - use lavage
- IV antibiotics
What is gout?
Arthritis caused by deposition of MSU crystals
- MonoSodium Urate —> needle shape
- Risks —> hyperuricaemia (high uric acid)
- genetics
- high purine diet
- kidney failure —> dec excretion - Onset —> abrupt
What is pseudogout?
Arthritis caused by deposition of CPPD crystals
- Calcium PyroPhosphate Dihydrate —> brick shape
- Risks —> elderly
—> background osteoarthritis
—> intercurrent infection
How is gout diagnosed? (5)
- Clinical:
- Gouty arthritis —> sudden, severe joint pain
- Tophi —> visible MSU crystal deposits
- hands, feet, elbows, ears - Monoarthritis
- Specific joints —> podagra (first MTP), feet, ankle,
knee, wrist, finger, elbow
- Blood:
- CRP inc
- Serum urate inc
- X-rays:
- Juxta-articular erosions —> looks like rat bite
- over time
- Juxta-articular erosions —> looks like rat bite
- Joint Aspiration:
- MC&S —> gram stain (rule out septic)
- Polarising Light Microscopy —> -ve birefringence
(+ve = pseudo-gout)
- Synovial Fluid Aspiration
- MC&S —> gram stain (rule out septic)
- Polarising Light Microscopy —> -ve birefringence
(+ve = pseudo-gout)
How is gout treated? (4)
Acute —> dec inflammation
1. NSAIDs = Non-Steroidal Anti-Inflammatory Drugs
2. Glucocorticoids
Chronic —> dec uric acid levels
3. Lifestyle eg. dec purine intake, dec beer
4. Drugs - allopurinol
- febuxostat
What is rheumatoid arthritis?
Arthritis of synovial joints caused by auto-antibodies:
- Rheumatoid factor —> IgM antibodies
—> bind to Fc of IgG
- not definitive
ACPA = Antibodies to Citrullinated Protein Antigens
- test for anti-CCP antibody (Cyclic Citrullinated
Peptide) —> more definitive + suggests more
aggressive
- inhibit: aginine —> citrulline (enzyme = PADs)
- Onset —> chronic
How is rheumatoid arthritis diagnosed? (5)
- Clinical:
- Morning stiffness
- Symmetrical joints affected —> hands, feet, wrists
- Polyarthritis
- Synovitis —> PIP, tenosynovium (around tendons),
bursa (knee) - Extra-articular disease - ocular (episcleritis)
- interstitial lung disease
- nodules (ulner border)
- vasculitis
- Blood:
- Hb low/normal (anaemia)
- PLT high/normal
- ESR high (Erythrocyte Sedimentation Rate)
- CRP high
- Rheumatoid factor —> +ve in 80% diagnosed
- X-ray:
- Soft-tissue swelling
- Peri-articular osteopenia
- Joint erosions —> established
- Ultrasound:
- Synovial hypertrophy —> thicker
- Doppler signalling —> inc blood flow
- Erosions
- MRI
- Synovitis
- Doppler signalling —> inc blood flow
Which joints are typically affected by rheumatoid arthritis? (6)
- PIP = Proximal InterPhalangeal
- MCP = MetaCarpoPhalangeal
- MTP = MetaTarsoPhalangeal
- Wrists
- Knees
- Ankles
What is the pathology of rheumatoid arthritis?
- Inc pro-inflammatory cytokines (TNF-α) to synovium
- Synovium proliferation —> neovascularisation
—> lymphangiogenesis
—> inflammatory cell
recruitment
How can blood tests differentiate between different types of arthritis? (5)
- Hb - low —> rheumatoid
- WCC - high —> septic
- PLT - high —> rheumatoid
—> septic - ESR - high —> rheumatoid
—> septic - CRP - high —> rheumatoid
—> septic
How is rheumatoid arthritis treated? (4)
Short-term —> dec inflammation
1. NSAIDs (sometimes)
2. Glucocorticoids
Long-term —> DMARDs (Disease-Modifying Anti-
Rheumatic Drugs)
3. Combination - first line
—> methotroxate + hydrochloroquine
(+ sulfasalazine)
—> Intramuscular injection or oral
steroids (short course)
4. Biological - second line
—> inhibit TNF-α via antibodies/ fusion
proteins (IV infusion or sub-cutaneus
injection)
—> eg. anti-TNF-alpha blockade
What are the clinical differences between rheumatoid arthritis vs osteoarthritis?
RA:
- age —> 30-50
- onset —> rapid
- joint pattern —> symmetric (bilateral)
- movement —> pain better
- morning stiffness > 1 hour
- joints —> hand: PIP, MCP
—> wrist, ankle, elbow
- swelling —> inflammation
- blood ESR/CRP —> high
- serology (RF) —> +ve
OA:
- age —> >50
- onset —> slow
- joint pattern —> asymmetric
- movement —> pain worse
- no morning stiffness
- joints —> hand: DIP, first CMC
- swelling —> bony
- blood ESR/CRP —> normal
- serology (RF) —> -ve
What is seronegative inflammatory arthritis?
Arthritis caused by auto-immunity (not antibodies)
What are the 4 types of seronegative inflammatory arthritis?
- Psoriatic arthritis
- Reactive arthritis
- Ankylosing spondylitis
- IBD-associated arthritis
What is psoriatic arthritis?
Arthritis associated with psoriasis
- 10% psoriasis patients
- usually —> asymmetrical
—> DIPs and PIPs
- also —> symmetrical of small
—> oligo (2-4) of large
—> spinal and sacroiliac inflammation
What is reactive arthritis?
Arthritis following an infection elsewhere
- Sterile arthritis
- Infections —> urogenital
—> GI
- 1-4 weeks before
- Extra-articular manifestations —> tendons
(enthesitis), skin, eye
- May indicate HIV or Hep C infection
- Risks —> genetic (HLA-B27) + environmental trigger
What is SLE?
Arthritis caused by autoantibodies against nucleus (nucleic acids and proteins):
- ANA = AntiNuclear Antibodies
- not specific - -ve —> no SLE
- +ve —> maybe SLE
anti-dsDNA antibodies = Anti-Double Stranded DNA
- high specificity
- Multi-site inflammation —> joints, skin, kidneys,
blood
- Risks —> female 9:1
—> age 15-40
—> ethnicity African + Asian
How can you differentiate between degenerative and inflammatory arthritis?
Degenerative —> no inflammation
Inflammatory —> inflammation
How can you differentiate between the 3 types of inflammatory arthritis?
Septic —> infection
—> acute + mono
Crystal —> acute + usually mono
Autoimmune —> chronic
How can you differentiate between the 3 types of inflammatory autoimmune arthritis?
Rheumatoid —> poly + symmetrical
Seronegative —> mono/oligo + asymmetrical
SLE —> polyarthralgia
What clinical questions should be asked to diagnose arthritis? (8)
- Inflammation?
- Onset?
- Movement —> worse/better?
- Morning stiffness?
- Joint number?
- Joint size?
- Joint pattern?
- Spine?
