14. Arthritis Flashcards
What is Arthritis?
Defined as “inflammation of a joint”, though often “arthritis” describes a disease or group of diseases associated with single or multi joint inflammation.
A 25 year old female presents to A&E with a 2 day history of pain in right knee. She is an intravenous drug user, with no other significant past medical history.
On examination: Red, hot and swollen right knee with a reduced range of movement. The patient is febrile (38.5 ͦ C).
Blood tests have been sent and the patient is stable.
What is the next most appropriate course of action?
A. Request review by orthopaedic surgeon
B. MRI knee
C. X-ray of the knee
D. Start broad-spectrum IV antibiotics
E. Aspirate the joint effusion
E. Aspirate the joint effusion
Important to aspirate the joint before giving antibiotics in septic arthritis if patient stable to improve ability to grow and thus detect causative pathogen.
Ortho r/v should occur prior to aspiration in a patient with a prosthetic joint, as arthrocentesis should not occur outside of sterile environment.
MRI may show associated osteomyelitis, but not appropriate at this stage.
Joint aspirate colours and meaning
Green/yellow pus – white blood cells (predominantly neutrophils and will contain causative bacteria)
Sterile - Reactive Arthritis
Septic arthritis Definition, Aetiology and RF
Definition: Infection of one or more joints caused by pathogenic bacteria.
Aetiology:
Direct bacterial inoculation
Haematogenous spread
- Staphylococcus aureus (60%) - Neisseria gonorrhoea (in young sexually active)
Risk factors:
- Pre-existing joint disease (e.g. RA)
- Immunosuppression (e.g. DM, iatrogenic)
- Prosthetic joints
- IVDU
Symptoms & signs of Septic arthritis
- Acutely inflamed tender, swollen joint
- ↓Range of movement
- Systemically unwell (e.g. fever)
- Knee most commonly affected
History usually <2 weeks duration.
Septic arthritis Investigations
Urgent joint aspiration:
- Gram stain & culture
- White blood cell count
Bloods:
- ESR/CRP, WCC, Blood cultures
Imaging to identify underlying pathology (e.g. osteomyelitis, chondrocalcinosis)
- X-ray, MRI
Ortho to do aspiration in theatre for joint prothesis.
Septic arthritis Mx
IV antibiotics (after aspiration) Analgesia Consider joint washout under GA
A 54 year old man presents to A&E with severe pain in his left foot. The pain started suddenly 45 minutes ago. He denies any trauma, and has only recently been discharged following treatment for pneumonia.
On examination: Red, hot and swollen metatarsophalangeal joint. His basic observations are normal.
Bloods: ↑WCC, ↑CRP, uric acid normal
Joint aspiration: Needle-shaped negatively birefringent crystals
What is the most likely diagnosis?
- Gout
- Pseudogout
- Septic arthritis
- Reactive arthritis
- Osteomyelitis
Gout
“Worst pain I’ve ever had doctor”
Most likely to be gout, given the severity & rapid-onset of the pain, and the joint involvement pattern (MTP). Dehydration often predisposes to gout – in this case the recent pneumonia likely contributed to this.
Gout Definition, Aetiology, RF
Definition: Acute monoarthropathy with severe joint inflammation, secondary to deposition of monosodium urate crystals.
Aetiology:
↑Uric acid (Purine metabolite)
- Under excretion
- Over-production
Gout Risk factors:
Male gender
- High cell turnover state (e.g. tumour lysis syndrome, lymphoma, psoriasis) = high endogenous purine metabolism
- Drugs (e.g. diuretics, aspirin, cytotoxics)
- Alcohol excess
- Purine rich diet (e.g. meat, seafood)
- Renal impairment (decreased excretion)
Gout Symptoms
Symptoms:
- Rapid-onset severe pain – “worst pain ever”
↓Range of movement
- Most commonly affects joints in feet
- First metatarsophalangeal joint (podagra)
Symptoms:
- Acutely – swollen joint
Long term:
- Tophi can deposit over extensor joint surfaces (particularly elbows and knees) and may be evident in helix of ears.
- Uric acid stones can cause renal tract obstruction & interstitial nephritis.
Give examples of radiodense (opaque), intermediate lucency and radiolucent stones
- Radiodense (radiopaque) stones: Calcium Oxalate & Struvite
- Intermediate lucency: Cystine
- Radiolucent stones: Uric Acid
Gout Investigations:
Blood:
- Serum uric acid (can be normal in acute attack, can be falsely low or normal during); NB: can also be normal or low serum acid
Synovial fluid:
- Polarised light microscopy
- Negatively birefringent needle-shaped crystals
X-ray:
- Early – soft tissue swelling and joint effusion
- Late – juxta-articular ‘punched-out’ erosions (also called rat-bite erosions)
Gout Management
- Acute: NSAIDs/colchicine
- Chronic: Conservative & allopurinol
Pseudogout definition, EF and Symptom/Signs
- Definition: Inflammation of a joint, secondary to deposition of calcium pyrophosphate crystals
- Risk factors: Elderly Hyperparathyroidism Hemochromatosis Osteoarthritis
- Symptoms & signs:
Very similar to gout
Commonly wrist or knee
Pseudogout Invx and Mx
Synovial fluid (Polarized light microscopy) - Positively birefringent rhomboid-shaped crystals
X-ray:
- Chondrocalcinosis (e.g. ca deposition in knee cartilage)
Mx: same as gout
DDx Septic Arthritis, Gout and Pseudogout
Septic arthritis
- Bacterial infection
- White cells and bacterial growth
Gout
- Monosodium urate
- NeGative birefringence
Pseudogout
- Calcium pyrophosphate
Positive birefringence
Joint aspiration is essential in the assessment of an acutely inflamed joint.
A 21 year old man presents with a 3 week history of a painful, hot, swollen right knee. He denies trauma or fever. He also complains of pain in his left heel. He was treated for a chlamydia infection 6 weeks ago.
What is the most likely diagnosis?
A. Gout B. Pseudogout C. Septic arthritis D. Reactive arthritis E. Rheumatoid arthritis
D. Reactive arthritis
Reactive arthritis definition, aetiology, RF
Definition:
- A sterile arthritis (one of HLA-B27 associated seronegative spondyloarthropathies), typically affecting the lower limb ~1-4 weeks after urethritis or dysentery.
Aetiology:
- Post-infection joint inflammation
(Chlamydia,Salmonella,Campylobacter,Shigella, Yersinia)
Risk factors:
- Male gender (9:1) for chlamydia-induced reactive arthritis
- HLA-B27 genotype (30-50%)
- Preceding infection
Symptoms of Reactive Arthritis
- Asymmetrical oligoarthritis
(Worse in morning) - Knee most commonly affected
Around 25% of patients have recurrent episodes whilst 10% of patients develop chronic disease
Reactive arthritis Signs
- Enthesitis (e.g. Achilles’ tendonitis)
- Keratoderma blenorrhagica (Brown raised plaques on soles and palms)
- Mouth ulcers
- Conjunctivitis
- Circinate balanitis (Painless and plaque-like lesion on the shaft or glans of the penis)
What syndrome is RA associated with?
Reiter’s syndrome - ‘Can’t see, pee or climb a tree’
- Arthritis
- Urethritis
- Conjunctivitis
A 56 year old woman presents with pain and stiffness of her hands. This pain is particularly bad at the end of the day. She has occasionally dropped things, and thinks her grip has become worse. She is taking regular over the counter analgesia. Heberden’s (Distal interphalangeal joints) and Bouchard’s nodes (proximal interphalangeal joints).
What is the most likely
diagnosis?
Rheumatoid arthritis Osteoarthritis Reactive arthritis Psoriatic arthritis Systemic sclerosis
Osteoarthritis
History of pain and stiffness in hands at the end of the day is classic for OA.
A 67 year old woman presents with pain, swelling and stiffness of her left knee. This pain is particularly bad after walking the dog.
On examination there is swelling of the left knee and a reduced range of movement. She has an antalgic gait.
What is the most likely
diagnosis?
Rheumatoid arthritis Osteoarthritis Reactive arthritis Psoriatic arthritis Systemic sclerosis
Osteoarthritis
Antalgic gait develops as a way to avoid pain while walking (A shortened stance phase in painful limb)
Image is a weight bearing AP plain radiograph of knees. This shows a right-sided total knee replacement and features of osteoarthritis in the left knee.
These can be remembered as LOSS:
Loss of joint space
Osteophytes
Subchondral sclerosis
Subchondral cysts
Osteoarthritis Definition and Aetiology and joint involvement
Definition: Degradation of cartilage and the underlying bone, leading to inflammation and osteophyte formation.
Aetiology:
Mechanical stress
Joint involvement:
- Small: DIPs, PIPs, thumb CMC
- Large: knees, hips
OA Risk factors
Age > 50 Female gender Obesity Physical/manual occupation Family history of OA
Osteoarthritis Symptoms:
(Gradual in onset) Pain Worse with movement, relieved by rest Worse at end of day Stiffness Especially after rest Reduced range of movement
OA Signs
Bouchard’s (PIP) & Heberden’s (DIP) nodes. Thumb squaring ( 1st CMC).
Fixed flexion deformity
Crepitus
Antalgic gait
Investigations for OA
X-Ray: Loss of joint space Osteophytes Subchondral sclerosis Subchondral cysts
Mx for OA
MDT approach (physio strengthening exercises, weight loss, supports/braces, insoles etc)
Analgesia
NSAIDs
Joint injection
Joint replacement - Most effective treatment for pain relief in OA
A 55 year old woman presents with painful and swollen joints in her hands. Her hands are stiff for over an hour after waking every morning. She is taking regular over the counter analgesia.
On examination:
Boutonnieres and Swan Neck
What test is the most specific for
the likely diagnosis?
Erythrocyte sedimentation rate C-reactive protein Rheumatoid factor Anti-cyclic citrullinated peptide Anti-nuclear antibody
Systemic sclerosis
Anti-cyclic citrullinated peptide
Rheumatoid hands
Anti-CCP is most specific test for RA. RF is a useful test in RA, though is less specific than anti-CCP. ANA is commonly associated with systemic lupus erythematosus. ESR and CRP are general markers of inflammation.
Definition of RhA, aetiology and joint involvement
Chronic systemic inflammatory disease characterised by a symmetrical, deforming, peripheral polyarthritis.
Aetiology:
Autoimmune joint destruction
Joint involvement:
MCPs, PIPs
No DIP joint involvement
Epidemiology and Risk factors of RhA
1% of population - common
HLA-DR4 = increased disease severity
Age 50-60 years
Female gender (>2:1)
Smokers
Family history of RA (HLA-DR4/DR1 linked)
Rheumatoid arthritis Symptoms
(Duration >6 weeks)
- Bilateral and symmetrical joint pain (MCPs, PIPs, wrist, MTP)
Stiffness worse in the morning lasting >1 hour (inflam) relieved by use
Movement and grip likely to be restricted due to pain, swelling and stiffness.
Articular Signs of RhA
Early – Joint inflammation (Tender swollen joints)
- Positive ‘squeeze test’
- MCPs, PIPs, wrist, MTPs
Late – Joint damage & deformity
- Swan-neck: rupture of lateral slips → PIPJ hyper-extension
- Boutonnière: rupture of central slip of extensor expansion → PIPJ prolapse through “button-hole” created by the two lateral slips.
- Z-thumb
- Ulnar deviation of fingers at MCPs
Extra-articular Signs of RhA (Most important)
- Rheumatoid nodules: Usually subcutaneous lumps, particularly over bony prominences, though can occur in the lining of internal organs (classically the lungs)
- Scleritis/episcleritis
- Anaemia
- Amyloidosis
Extra-articular Signs of RhA (All)
General: Malaise, lethargy, low grade fever, weight loss
Cardiovascular: Increased of cardiovascular disease & pericarditis/pericardial effusion
Respiratory: Nodules, pleural effusion, pulmonary fibrosis, pneumoconiosis (Caplan’s syndrome)
Renal: Amyloidosis
Neurological: Peripheral neuropathy, carpal tunnel syndrome, mononeuritis multiplex, atlanto-axial subluxation
Opthalmological: Scleritis, episcleritis, keratoconjunctivitis sicca
Haematological: Anaemia (multifactorial – Anaemia of chronic disease, iron-deficiency anaemia secondary to NSAID-induced gastritis/ulcer, aplastic anaemia secondary to DMARD use, methotrexate-induced folate deficiency, pernicious anaemia)
What is Felty’s syndrome?
↓WCC + splenomegaly + RA
Rheumatoid arthritis investigations
Blood:
- ↑CRP & ESR in ‘active’ disease
- Rheumatoid factor (circulating IgM specific for self IgG Fc): Positive in ~70%, High titres are associated with disease severity and extra-articular manifestations
- Anti-cyclic citrullinated peptide antibodies (Anti-CCP) - More specific marker for RA
Imaging:
- X-ray
- Ultrasound and MRI can identify synovitis more accurately
Management for RhA
MDT approach
Medical therapy includes NSAIDs, analgesia, DMARDs (methotrexate, sulfasalzine & hydroxychloroquine), corticosteroid for acute flares and biologics (Anti-TNF agents – Infliximab, etanercept and Anti-CD20 - Rituximab)
The American College of Rheumatology criteria can be used to diagnose what disease and what does it use?
The American College of Rheumatology criteria can be used to diagnose RA. This criteria uses pattern of joint involvement, serology, biochemistry and symptom duration to establish diagnosis.
Amyloidosis Definition and 3 types
Definition: A group of disorders characterised by deposition of protein in an abnormal fibrillar form, resistant to degradation
AL Amyloid (primary) AA Amyloid (secondary) Familial Amyloidosis (AD mutation in transthyretin, transport protein produced by liver)
AL Amyloid Aetiology, RF
Aetiology
- Proliferation of plasma cell clone → monoclonal immunoglobulins → fibrillar protein deposition
Risk factors
•MGUS (pre-MM state; paraprotein in serum but no myeloma)
•Multiple myeloma
•Lymphoma
AA amyloid Aetiology, RF
Aetiology
- Chronic inflammation → chronically elevated serum amyloid A (acute phase protein) → fibrillar protein deposition
Risk factors
- Rheumatoid arthritis
- Inflammatory bowel disease
- Chronic infection: TB, bronchiectasis, osteomyelitis
Inflammatory polyarthropathies (RhA, AS, Psoriatic, Juvenile arthritis) account for 60% of AA amyloid cases.
AL Amyloid (primary) vs AA Amyloid (secondary) - symptoms and joint involvement
Symptoms and signs will be dependant of organ involvement. Often non-specific (fatigue, weight loss etc). Large amount of crossover in presentation between AA and AL. Almost any organ can be affected.
AL Amyloid (primary):
- Restrictive cardiomyopathy
- Peripheral neuropathy
AA Amyloid (secondary)
- Nephrotic syndrome
- Hepatomegaly
- Splenomegaly
Invx findings for Amyloidosis
Histological diagnosis from biopsy of affected tissue
Positive Congo-red staining with red-green birefringence under polarised light microscopy.
Amyloidosis Key hints for Year 3 SBAs
- Many years history of paraproteinaemia or chronic inflammatory disease
- Presents with non-specific symptoms or nephrotic syndrome
- Periorbital purpura
- Macroglossia
A 60 year old woman presents with painful and swollen joints in her hands. Her hands are stiff in the mornings and after periods of rest. The stiffness eases with activity.
On examination: Asymmetrical oligoarthropathy, DIP involvement, nail pitting + onycholysis
What is the most likely diagnosis?
Rheumatoid arthritis Osteoarthritis Reactive arthritis Psoriatic arthritis Systemic sclerosis
Psoriatic arthritis
Around 10-20% percent of patients with skin lesions develop an arthropathy. Arthritis can present before skin changes.
Spondyloarthritides Definition
Group of inflammatory arthritides affecting the spine and peripheral joints without production of rheumatoid factor and associated with the HLA-B27 allele. Seronegative (RF -ve)
4 types of Spondyloarthritides
Ankylosing spondylitis
Psoriatic arthritis
Reactive arthritis
Enteropathic arthropathy
Clinical features of Spondyloarthritides
- ‘Axial arthritis’ – spine & sacroiliac joint involvement
- Enthesitis (Inflammation of the site of insertion of tendon or ligament into bone) – Achilles tendonitis, plantar fasciitis, costochondritis
- Dactylitis (Inflammation of an entire digit due to soft tissue oedema, and tenosynovial and joint inflammation)
Extra-articular features of Spondyloarthritides
Extra-articular:
- Anterior uveitis (iritis)
- Psoriaform rashes
- Oral ulcers
- Aortic regurgitation
- Inflammatory bowel disease
5 Types of Psoriatic arthritis, in order of prevalence
Variable presentation of joint involvement, nail changes in 80%
- Symmetrical polyarthritis (RhA like)
- Asymmetrical oligoarthritis
(typically hands and feet) - DIP predominant (high incidence of nail changes)
- Spondylitis (Spine and sacroiliac involvment)
- Arthritis multilans (Severe deformity, telescoping fingers)
Invx and Mx of Psoriatic arthritis
X-Ray: Pencil-in-cup deformity
Mx: Similiar to RhA
A 29 year old man presents to the GP with lower back pain and stiffness for the last 3 months. His symptoms are worse in the morning and improve with exercise. He also complains of a painful Achilles tendon when walking. You note that he last attended the practice 1 month ago with a red eye.
What is the most likely diagnosis?
Spinal stenosis Multiple myeloma Ankylosing spondylitis Reactive arthritis Polymyalgia rheumatica
Ankylosing spondylitis
Most likely diagnosis is ankylosing spondylitis – Inflammatory sounding back pain (worse in morning eases on exercise) + Red eye = iritis, Achilles tendonitis = enthesitis
Spinal stenosis – Classically causes neurogenic claudication (Pain and weakness of calves and thighs when walking), may also have numbness or parasthesia
Multiple myeloma - Common cause of lower back pain in ELDERLY. Features are remembered as CRAB: Hypercalcaemia, Renal injury, Anaemia, Bone pain.
Ankylosing spondylitis Definition and Risk factors
Chronic progressive inflammatory arthropathy of the spine and sacroiliac joints
Risk factors: Male gender (2.5:1) Age <30 years Family history of ankylosing spondylitis HLA-B27 positivity (80%)
AS Symptoms
Back pain Midline Worse in morning Improvement with exercise Insidious onset (>3 months duration)
AS Signs
Sacroiliac tenderness
Progressive loss of spinal movement
- Schober’s test: two points are marked on the patient’s back (10 cm above and 5 cm below the posterior superior iliac spine). The distance between the two points should increase by more than 5 cm when the patient bends as far forward as possible. If the increase is smaller than 5cm, then this demonstrates a restriction in pumbar flexion and Schober’s test is positive
AS Invx
Pelvic x-ray:
- Sacroiliitis (Radiographically apparent sacroiliitis may take many years to develop; normal pelvic x-ray =/= exclude Dx)
- Vertebral body squaring
- Syndesmophytes (Ossification of outer fibers of annulus fibrosus)
- ‘Bamboo spine’ (Rare late sign)
AS Mx
Intense exercise regimens, NSAIDs, TNF alpha blockers.
