Arthropathies Flashcards
Differentials for leg pain
A. Dermatomyositis.
- Capillary vasculopathy
- Idiopathic inflammatory myopathy of childhood
- Symmetrical proximal weakness (Gower sign)
- Rash - Gottron patches, helitrope rash, calcinosis
- High CK
- Myopathic EMG
- Biopsy - inflamm and necrosis
B. Guillian-Barré syndrome
- acute inflammatory demyelinating polyradiculopathy
- primarily motor: progressive symmetrical ascending weakness
- ↓ reflexes
- +/- triggering event (infection (campylobacter/ mycoplasma) etc 2 weeks prior
- may have sensory/ autonomic involvement
- normal or slightly ↑ CK
- Starting distally
- ?Weakness
C. Reactive arthritis
- Joint inflammation - sterile inflammatory infection due to recent infection
- Usually oligoarticular (usually lower limbs)
- following GI (Salmonella, Shigella, Yersinia, Campylobacter) or GU (Chlamydia, Gonococcus) infection
- post-infection by several days/ weeks → x-reactive to joint antigens → activate T-cells
- usually no fever - can mimic septic arthritis
- ↑ ESR/ FBE may be normal
- Reiter’s disease - conjuntivitis, urethretitis, arthritis
D. Rhabdomyolysis.
- breakdown of muscle
- Weakness, pain,
- normal reflexes
- High CK
E. Viral myositis.
- Muscle pain, weakness, high CK
- Severe pain sudden onset, usually in calves (also back)
- May be absent reflexes secondary to weakness
- Commonly post influenza A, B, enteroviruses, EBV, CMV
- Resolves 1-2 weeks
- NSAIDs
Back pain: outline DDx and key features
Discitis
- Infection within disc space
- Affects 1-5y/o
- Tender to palpate/pain (i.e on nappy changes)
- Decreased movement/loss of lumbar lordisis
- Less than half are febrile
- 50% staph in blood culture
- MRI loss of disc space, inflammation
- Rx long term ABx
Ankylosing spondylitis
- Long term back pain
- Progressive stiffness, insidious onset
- Recurrent episodes of pain
- Bamboo spine/sacroiliitis on MR/XR
Epidural abscess
- Fever and high CRP
- Leads to compression of nerves with sensory, motor and autonomic changes
- Spines/surgery/immunocompromised
Osteoid osteoma
Benign bone tumour
- Benign bone-forming tumor and the most common tumor that presents with back pain in children
- Nocturnal pain
- Relieved by NSAIDs
- 10-20% in spine
Key points for NSAIDs in Rheum
- Naproxen
- Ibuprofen
- Meloxicam
JIA subtype - polyarthritis, oligoarthritis, sJIA
- Require 4-6 weeks to achieve anti-inflammatory effect
- COX inhibition = reduces prostaglandins that promote inflammation
- Main side effects = nauseas, appetite, abdominal pain, gastritis (less frequent in children
Side effects
- Gastritis
- Renal and hepatic toxicity
- Pseuodoporphyria (bullous photosensitivity that clinically and histologically mimics porphyria cutanea tarda)
- Rare effects:
- Ibuprofen = aseptic meningitis in lupus
- Naproxen = pseudoporphyria: small hypopigmented areas in skin trauma
What are overview key points for JIA?
Pathogenesis:
- Immunogenetic susceptibility and external trigger
- T lymphocytes release proinflammatory cytokines - TNF alpha, IL6, IL1
Clinical:
- Arthritis - morning stiffness, joint swelling, effusions, loss of function, any joint, large > small, axial, SI, TMJ
- Systemic symptoms - fever, LOW, fatigue, anaemia
- Extra-articular - growth, osteopenia, cardiopulmonary, uveitis
Diagnosis
- Age < 16 years, arthritis, Sx lasting > 6 weeks
Ix
- FBE and film - inflamm thrombocytosis, anaemia, leukocytosis
- CRP, ESR
- ANA - predict risk of uveitis (note 15% of normal children are positive)
- RF - low yield, if positive severe illness course
- MAS - clotting cascade, ferritin, D-dimer, fibrinogen, LDH, trigs, LFTs
- Xrays - osteopenia, soft tissue swelling, joint space narrowing
- US - effusions
Classification (see other cards)
- sJIA - quotidian (daily) fever, evanescent erythematous rash, lymphadenopathy, hepatosplenomegaly, serositis
- Oligoarthritis (<4 joints)
- Polyarthritis (>5 joints) - RF positive, RF negatve
- Psoriatic
- Enthesitis related - SI joint, HLA-B27 pos, acute symptomatic uveitis
- Undifferentiated
Mx
- NSAIDS -
- Steroids - PO, IV, intra-articular
- DMARDS:
- Non biologics - methotrexate, Sulfasalazine
- Biologics:
- TNF alpha inhibitors - infliximab
- Anti IL1 - anakindra
- Anti IL6 - tocilizumab
Tx algorithm
- Trial NSAID 4-6 weeks - 25-35% response rate 4-6 weeks
- If no response/functional limitation - intra-articular steroids
- If no response - DMARDs
What are the features of sJIA
- Migratory joint pain
- Fever
- Rash (evernescent fevers )
- Pericarditis
Polyarteritis nodosa
Tender subcutaneous lumps
HSP like lesions
Can present with
Dermatomyositis
Dermatomyositis
Inflammatory disorder of skin & muscle
Autoimmune condition
Pathophysiology
Autoantigen (soluble) in muscle & skin, endothelial capillary in muscle
Complement cascade -> cell lysis by MAC -> inflammatory
Immune complexes deposited in blood vessel walls
Damage to blood vessels -> tissue ischaemia
HLA-DR3
Muscle weakness- proximal
- pharynx: dysphagia
- shoulder/hip: difficulty standing up/overhead activities
Rash
- heliotrope
- eyelids
- shoulder, chest & back (shawl)
Gottrons papules
- fingers, elbows & knees
- photosensitive
ANA
Anti-Mi2 & Jo1
Elevated CK
Abnormal EMG
Biopsy- inflammation of paramysium
Rx
Immunosuppresants- corticosteroids
Hydroxychloroquine
Cx
Osteoporosis, calcinosis, lidodystrophy, cardiac, bowel wall vasculitis, asp pneumonia
1) Weakness - Symmetrical, proximal weakness and truncal weakness - Inability to sit up/head lag/Gower sign, Trendelenberg positive - Oesophageal and resp muscles can be affected - dysphonia, dysphagia, reflux
2) Rash - Heliotropic rash - discolouration of eyelids with periorbital edema (85%) - Gottron papules - bright pink/pale shiny plaques over PIP and DIP
3) Calcinosis and lipodystrophy - Calcinosis - deposition of calcium phosphate - subcut plaques/nodules - Lipodystrophy - loss of subcut and visceral fat over face and upper body
Nail fold capillary changes (80%) - dilated, leaking vessels, telangiectasia
Non-biologic DMARDs? (methotrexate, sulfasalazine, leflunomide)
Methotrexate
Methotrexate
JIA
Dermatomyositis
Inhibits dihydrofolate reductase
Blocking purine nucleotide biosynthesis
GI toxicity
Hepatotoxicity
Nephrotoxicity
Pneumonia
Rash
Alopecia
Bone marrow suppression
Teratogenic
FBE/LFTS: every 4 weeks for first three months, then 8-12 weeks
Give with folic acid
Avoid with: penicillin, sulphonamides, aminoglycosides, NSAIDs, PPIs and valproate (increase toxicity)
Accumulates in third spaces
Oligoarticular JIA?
Oligoarticular JIA
Frequency
50-80% (65%)
Definition
- <4 joints in first 6 months (4 or less)
- Large joints
Age
Early
Peak age - 1-5
Gender
F>M 4:1
Distribution
- Large (LL > UL – knees ++, ankles, wrists, elbows)
- Hip unusual
RF
Rarely
ANA
~ 60%
Complications
Anterior uveitis (chronic most common) ~ 30%
Usually asymptomatic
Most common in patients ANA positive
20-30% risk
Within 2 years
Slit lamp screening until 12yrs
Lab
ANA pos ~60% (more likely to have uveitis)
Other tests normal
Mildly raised ESR, CRP
Leukocytosis
Normal
Anaemia
No
Elevated ESR
Mild
Elevated ferritin
No
Destrutive arthritis
Rare
Management
NSAID
Intra-articular steroids
MTX occasionally
Response to MTX
Excellent
Response to biologics
TNF inhibitors - excellent
IL6 inhibitors - excellent
(Although not used much)
IL1 - poor
Polyarticular JIA? Including differences for RF negative and positive subtypes?
Polyarticular JIA
15-25% (20%)
- >4 joints in first 6 months (5 or more)
Two peaks – early childhood 2-4years + adolescence
F>M
Small + large
Symmetrical (UL + LL – hands and wrists)
Other – TMJ, C-spine
Usually systemic features
Sero + adult Ra like =
Rheumatoid nodules, erosions, lower rate remission
Labs
- ANA pos 40%
- ESR and CRP raised
- mild anaemia
Destructive arthritis - >50%
Response to MTX - Excellent
TNF inhibitors - excellent
IL6 inhibitors - excellent
IL1 - poor
Systemic JIA
Systemic (sJIA)
5-10%, F=M
Key clinical
Arthritis (88%)
- May not be prominent feature early in disease
- Can affect hands, feet, wrist, ankles, knees, hips
Fever - quotidian (98%) daily
- Occurs daily or twice daily for at least 2 weeks
Rash
- Evanescent erythematous rash (81%)
- Linear, circular, trunk and prox extremities
- Salmon pink
- Non pruritic
- Associated with fever spikes
- Migratory lesions last < 1 hr
- Superficial trauma Koebner phenomenon
- Heat
Other
Lymphadenopathy 31%
Hepatosplenomegaly
Serositis
Pericarditis
Hepatitis
Pulmonary manifestations
Monophasic - resolves after 6 months
Polycyclic - recurs
Persistent
Throughout
(Still’s disease in Adult)
Polyarticular, large or small
Characteristic intermittent fever, salmon rash, HSM
Rarely RF
Rarely ANA
Complications
MAS
Growth failure
Osteoporosis
Pulmonary complications
Dermatographism
Koebner’s (creases + recurrence with trauma)
Anaemia
Pericarditis
Pleuritis
Uveitis rare
MAS
Labs
Anaemia
Leukocytosis ++
High ESR
- Sudden fall of ESR/platelets onset of MAS
High CRP
High ferritin (500-1000, >1000 MAS)
Thrombocytosis
Mx
Trial NSAIDs if mild
Corticoteroids
IL1 (Anakinra) or IL6 (Toclizumab)
Less responsive to MTX and anti-TNF
Nb: diagnosis of exclusion (exclude infection/malignancy)
Psoriatic arthritis? (subtype JIA)
Psoriatic arthritis
5-10%
Arthritis + psoriasis (red plaques)
FHx
Dactylitis
Nail pits / onycholysis
+/- skin involvement
Two peaks
2-4years
9-11years
F>M
Asymmetric or symmetric
Large and small joints
DIP
Rarely RF
50% ANA pos
Acute uveitis 10%
(symptomatic)
Cutaneous - psoriasis, red scale plaques on extensor surfaces
Nail changes - pitting, onycholysis, hyperkeratosis
Labs:
ESR +
CRP +
Mild anaemia
Mx:
NSAIDs
Intra-articular steroids
MTX
Anti-TNF agents
Enthesitis-related arthritis?
Enthesitis related arthritis (ERA)
5-10% of JIA
Arthritis + enthesitis
Risk factors
HLAB27 +
FHx ankylosing spondylitis
**Spondyloarthropathy
Late – boys >6years
F
Lower back or sacroiliitis
Hip and intertarsal joints
Enthesitis – plantar fascia (MTP heads, calcaneus), tibial tuberosity, patella, Achilles, greater troch, SP, ASIS
Rarely RF pos
Rarely ANA pos
Acute uveitis 10%
(symptomatic)
Reactive arthritis
IBD
HLA-B27 positive in 80%
Mx
NSAID and intra-articular steroid
Consider sulfasalazine as alternative to MTX
Anti-TNF agents
Ankylosing spondylitis - what are key features, investigations, treatment
Ankylosing spondylitis
Inflammatory arthritis, progressive stiffening & fusion of axial skeleton
15% cases begin in childhood/adolescence, M>F
Usually presents with SEA syndrome:
- Rheumatoid factor Seronegativity
- *- E**nthesitis- around foot and knee
- Oligoarthritis- Legs> arms, esp hips, SI joint and axial skeleton usually affected later in the course of the disease.
Subset of spondyloarthropathies
- *Ankylosing spondylitis 🡪 ‘adult’ disorder**
- *Enthesitis related arthritis (ERA) 🡪 subtype of JIA**
- *Arthritis associated with IBD**
- *Reactive arthritis post GI / GU infections**
Features: insidious onset (usually teenager), recurrent back pain due to sacroilitis, worse in morning/with rest, loss of lordosis/flexion (Shober’s test), asymmetrical large joint olidoarthritis, enthesitis common in children (patella tendon, achilles tendon). Systemic features uncommon
Ix:
HLA-B27 +ve (90% affected, 8% unaffected population positive)
FBE, ESR- increased
Xray- heel spurs, sacroilitis - bamboo spine due to spondylitis (fusion of verebra)
MRI more sensative for sacroilits
- *Rx:**
- NSAIDs first line, steroid injections
- Sulfasalazine/MTX
- Anti-TNF, infliximab, adalimumab, etanercept
Uveitis and JIA
- Uveitis - inflammation of uvea (middle portion of eye - iris, ciliary body, choroid)
- Acute = symptomatic, painless, red
- Most common in ERA (10-15%)
- Chronic - asymptomatic
- Most common in oligoarthitis JIA (30%)
- Anterior - pain, redness, constricted pupil
- Posterior - painless
Risk factors for uveitis:
- Age < 6
- ANA positive
- RF negative
- Oligoarthritis JIA
- HLA-B27
- Time from diagnosis - 75% occurs within 3 years of Dx
Screening
High risk - age < 6, ANA pos - Eye Ex every 3 months, then go to 6, then 12
Medium risk - age >6, ANA pos, 6 months, then 12
Lower risk -< 6, ANA neg
Mx
Mydriatics
Corticosteroid
DMARDS
MTX and anti-TNF
SLE - features, Ix, Mx
Epidemiology: less common in children 1-6:100000, higher in Asians/African Americans, islanders, Hispanics, females 19-29yrs peak (unusual if <8yrs, caucasian)
HLA B8,DR2 & 3
Associated with complement & IGA deficiencies
Pathogenesis
- Chronic autoimmune disease, polyclonal B cell activation-→ widespread inflammation (form of Type 3 hypersensitivity)
Features:
Most common in children - fever, fatigue, haematological, arthritis, nephritis
- D - Discoid rash (rings)
- O- Oral ulcers
- P - Photosensitivity
- A - Arthritis - 2 or more joints, knees, carpal, fingers PIP
- M - malar rash - butterfly distribution, spares nose
- I - Immune markers
- N - Neurological - psychosis, seizures
- E - ESR
- R - Renal - nephritis
- A - ANA
- S - Serositis - pericarditis, pleuritis, peritonitis
- H - Haematological - cytopenias, haemolytic anaemia
Ix
- FBE - cytopenias
- Inflamm
- Coags
- Renal Ix
- Thyroid
Antibodies
- ANA (anti-nuclear Ab): high sen (95-99%0, low spec (50%), not reflective disease activity
- Anti-dsDNA (double stranded DNA) - correlates with disease activity, correlates with nephritis
- Anti-Smith - low sens, high spec (98%)
- Anti Ro - neonatal lupus
- Anti-La - neonatal lupsus
- Anti-ribonucleotide protein - raynuad’s
- Anti-ribosomal P - neuropsych
- Antiphosholipid Ab, cardiolipin - ⅔ SLE, recurrent preg loss
- Anti-histone Ab - drug induced lupus
Markers disease activity
- High dsDNA
- Decrease C3/C4
- Decrease Hb
- Increased ESR
- Low albumin
- Urine MCS/UEC/Pr:Cr
Mx
- Hydroxychloroquine (retinal pigmentation, colour vision, 6/12 opthal_
- Steroids
- Immunosuppressives - MTX, lefluunomide, AZA, MMF (mycophenolate), cyclophosphamide
- Severe - PO/IV cyclophosphamide
- Belimumab
