Rheumatology Flashcards
How should allopurinol be started for treatment of gout?
- indicated for all patients after first attack of gout
- delay until inflammation settled (once no longer in pain - no specific time frame)
- initial dose 100mg OD then titrated every few weeks to aim for serum uric acid <360 micromol/L
- colchicine or NSAID cover should be considered
What is the initial starting dose of allopurinol for gout?
100mg OD then titrate dose every few weeks to aim serum uric acid less than 360 micromol/L
Which patients should have a lower target uric acid level (<300 micromol/L)?
- those with tophi
- chronic gouty arthritis
- ongoing frequent flares despite uric acid <360
How long does the BSR suggest colchicine may need to be continued for when given as cover once allopurinol started?
may be needed for 6 months
What may be a protective factor from osteoporosis?
obesity - can convert androgens into oestrogen, helps maintain bone density
What is second-line when allopurinol is not effective?
febuxostat (if refractory: uricase, pegloticase)
For how long should NSAIDs be used when treating acute gout?
until 1-2 days after symptoms have settled
What is the mechanism of action of colchicine?
inhibits microtubule polymerisation by binding to tubulin (interfering with mitosis); also inhibits neutrophil motility and activity
What is the pathophysiology of gout?
caused by deposition of monosodium urate monohydrate in the synovium
Which foods should be avoided for gout?
liver, kidneys, seafood, oily fish (mackerel, sardines), yeast products
What drugs can precipitate gout?
thiazide diuretics
Which antihypertensive may be useful lin gout?
losartan - has specific uricosuric action
What will the findings of creatinine kinase and EMG be in polymyalgia rheumatica?
normal
In addition to glucocorticoids what are 6 medications that may worsen osteoporosis?
- SSRIs
- antiepileptics
- PPIs
- glitazones
- long term heparin therapy
- aromatase inhibitors e.g. anastrozole
What investigations should be requested for patients with osteoporosis?
FBC, ESR/CRP, calcium, albumin, creatinine, phosphate, ALP, LFTs, TFTs
DEXA (bone densitometry)
What is pseudogout?
deposition of calcium pyrophosphate dihydrate (CPPD) in and around joints - especially articular and fibrocartilage
What are 5 X-ray changes seen in rheumatoid arthritis?
- Loss of joint space
- Juxta-articular osteoporosis
- Subluxation
- Periarticular erosions
- Soft tissue swelling
What will radiographic changes show in pseudogout?
chondocalcinosis, linear opacification of articular cartilage
How many pseudogout present?
may be asymptomatic, or acute pseudogout episode or chronic arthritis
Which 3 joints are most commonly affected in pseudogout?
knees, wrists, hips
How is a diagnosis of acute pseudogout made?
compensated polarised microscopy on joint aspirate - crystals are rhomboid-shaped and weakly positively birefringent
What is the treatment of pseudogout?
- aspiration of joint to reduce pain
- NSAIDs
- intraarticular steroid
- systemic steroid
- colchicine if NSAIDs/steroids CI
What is one of the most common presenting features of patients with systemic amyloidosis?
renal dysfunction
How is a diagnosis of amyloidosis made?
- Congo red-binding material (bright green fluorescence observed under polarised light after Congo red staining) demonstrated in a biopsy specimen
- biopsies from any affected organ - capillaries in subcutaneous fat often involved + provide sufficient tissue
What is the treatment available for amyloidosis?
no specific treatment; therapy aims to suppress underlying plasma cell dyscrasia + supportive measures for organ function
What is the definition of reactive arthritis?
arthritis that develops following an infection where the organism cannot be recovered from the joint (urethritis + arthritis +- conjunctivitis)
How long after initial symptoms of infection does reactive arthritis tend to develop?
4 weeks
How long do symptoms tend to last for in reactive arthritis?
4-6 months
What pattern of arthritis is seen in reactive arthritis?
asymmetrical oligoarthritis of lower limbs (+- dactylitis)
Which 2 forms of eye disease may be seen in reactive arthritis?
- conjunctivitis
- anterior uveitis
What are 2 dermatological manifestations of reactive arthritis?
- circinate balanitis (painless vesicles on coronal margin of prepuce)
- keratoderma blenorrhagica (waxy yellow/brown papules on palms and soles)
When should allopurinol be started after an acute attack of gout?
once inflammation settled and patient no longer in pain (no specific time frame)
What is the underlying pathology in gout?
microcystal synovitis caused by deposition of monosodium urate monohydrate in synovium; caused by chronic hyperuricaemia
How long should NSAIDs/ colchicine be used for in an acute attack of gout?
until 1-2 days after symptoms have settled
What is the main side effect of colchicine?
diarrhoea
What treatment may be considered in an acute attack of gout if colchicine and NSAIDs are contra-indicated?
oral steroids e.g. pred 15mg / day
What is the mechanism of action of febuxostat?
xanthine oxidase inhibitor
Which joint is most commonly affected by gout + in what proportion of cases?
1st metatarsophalangeal (MTP) joint - 70%
What does synovial fluid analysis show in gout?
needle-shaped negatively birefringent monosodium urate crystals under polarised light
When should uric acid levels be checked in gout?
once acute episode has settled - usually 2 weeks later (may be high, normal or low during attack)
What are 6 findings on x-ray in gout?
- joint effusion (early)
- punched out erosions with sclerotic margins in juxt-articular distribution + overhanging edges
- preservation of joint space until late
- eccentric erosions
- no periarticular osteopenia (seen in RA)
- soft tissue tophi
What is Schober’s test in ankylosing spondylitis?
line drawn 10cm above and 5cm back dimples (dimples of Venus) - distance between should increase by >5cm on bending - if less test positive
What are 3 features on clinical examination of ankylosing spondylitis?
- reduced lateral flexion
- positive Schober’s test
- reduced chest expansion
What are 8 additional features of ankylosing spondylitis?
- Achilles tendonitis
- Anterior uveitis
- Aortic regurgitation
- Apical fibrosis
- AV node block
- Amyloidosis
- Cauda equina syndrome
- Peripheral arthritis
What are 3 side-effects of methotrexate?
- mucositis
- myelosuppression
- liver cirrhosis
- pneumonitis
- pulmonary fibrosis
What are 4 side effects of sulfasalazine?
- rashes
- oligospermia
- Heinz body anaemia
- interstitial lung disease
What are 3 side-effects of leflunomide?
- liver impairment
- interstitial lung disease
- hypertension
What are 2 side effects of hydroxychloroquine?
- retinopathy
- corneal deposits
What is a key side effect of gold (to treat RA)?
proteinuria
What are 2 side effects of penicillamine?
- proteinuria
- exacerbation of myasthenia gravis
What are 2 side effects of etanercept?
- demyelination
- reactivation of tuberculosis
What is a side effect of infliximab?
reactivation of tubcerulosis
What is a side effect of adalimumab?
reactivation of tubcerulosis
What is a side effect of rituximab?
infusion reactions common
How useful is serum HLA-B27 for diagnosing ankylosing spondylitis?
not useful - positive in 90% of patients with AS but also 10% of normal patients
What is the most useful investigation to establish a diagnosis of ankylosing spondylitis?
plain x-ray of sacroiliac joints
What are 5 radiograph changes in ankylosing spondylitis?
- sacroiliitis - subchondral erosions, sclerosis
- squaring of lumbar vertebrae
- bamboo spine (late + uncommon)
- syndesmophytes - due to ossification fo outer fibres of annulus fibrosus
- CXR - apical fibrosis
What should be done if xray is negative for sacroiliac joints in suspected ankylosing spondylitis, but suspicion is still high?
MRI - can show signs of early inflammation involving sacroiliac joints (bone marrow oedema)
What may be seen in spirometry in ankylosing spondylitis and why?
restrictive defect - combination fo pulmonary fibrosis, kyphosis, ankylosis of costovertebral joints
What is the first line management of ankylosing spondylitis?
encourage regular exercise, physiotherapy, & NSAIDs
What is the only time disease-modifying drugs are useful in ankylosing spondylitis and what are examples?
if there is peripheral joint involvement - sulfasalazine
What drug is suggested to treat ankylosing spondylitis by EULAR guidelines if disease activity is high despite conventional treatment?
anti-TNF e.g. etanercept, adalimumab
What is the management of fragility fractures (e.g. fractured NOF, Colles) aged over 75 vs under 75?
- > 75y: start bisphosphonate (e.g. alendronate) without waiting for DEXA
- <75y: DEXA scan - input results into FRAX
What is the initial step for management of chronic stable RA?
- DMARD monotherapy +- short course of bridging prednisolone: methotrexate most common (sulfasalazine/ leflunomide/ hydroxychloroquine)
What are 4 examples of DMARDs used for RA?
- methotrexate
- sulfasalazine
- leflunomide
- hydroxychloroquine
What monitoring is essential for patients on methotrexate and why?
- FBC, U+E + LFT: risk of myelosuppression + liver cirrhosis
- every week until therapy stabilised, then 2-3 monthly
other SE: pneumonitis
When is hydroxychloroquine considered for initial therapy in RA?
mild or palindromic disease
What is used to monitor response to treatment in RA?
CRP + disease activity (using composite score such as DAS28)