Rheumatology Flashcards
Test to distinguish gout form pseudogout
polarised red light of joint aspirate
Test result for gout on joint aspirate
monosodium urate crystals are negatively birefringent in polarised light– they will appear a needle shaped crystals.
Test results for pseudo gout on joint aspirate
Calcium pyrophosphate crystals are positively birefringent in polarised light– they will appear as rhomboid shapes
Drugs which increase risk of gout
Thiazide diuretics
Chronic symptoms or complications of gout
Tophi - urate deposits in skin esp pinna of ear. White lesions, feel chalky, proportional to severity of disease.
Nephrolithiasis.
Secondary osteoarthritis
Treatment of gout
Acute: NSAID, colchicine, prednisolone if renal impairment. Rest, elevate joint, ice packs.
Chronic: Allopurinol of more than 1 attack in a year, evidence of tophi or nephroliathsis. Also can low dose aspirin and lifestyle advice to change diet.
Pharmacology for allopurinol and monitoring.
Inhibits the enzyme xanthene oxidase.
Monitor serum urate level every 3 weeks to check effectiveness. Target for uric acid < 300
Check kidney functions.
Titrate slow and low. Do not start immediately after acute attack as can precipitate flare-up. Wait 3 weeks.
X-ray of gout
‘punched-out’ periarticular erosions.
Flecked calcifications.
Normal joint space.
Soft tissue swelling.
Most common area for gout and pseudogout
Gout = first metatarsophalangeal joint Pseudogout = knee
X-ray for pseudogout
Cartilage calcification/Chondrocalcinosis - white horizontal lines in cartilage.
x-ray for OA
Osteophytes from new born formation.
Joint space narrowing.
Bone cysts
Subchondral sclerosis.
x-ray for RA
Soft tissue swelling.
Loss of joint space.
Joint deformity and erosions.
Juxta-articular osteopenia.
Use of biologics in RA
If RA does not respond to 2 DMARDs, DAS28 >5.1
DAS28
Disease activity score in rheumatoid arthritis of 28 joints.
One criteria for starting anti-TNF is DAS28 >5.1.
3 examples of TNF alpha inhibitors
Infliximab, etanercept, adalimumab
Contraindications for TNF alpha inhibitors
pregnancy, breast feeding, severe HF, haematological malignancy, active infection.
Common side effects of TNF alpha inhibitors
Worsening HF, reactivation of TB, fever, injection site swelling.
Risk factors for septic arthritis
prosthetic joint, IVDU, immunosuppressant drugs e.g. chemo, steroids, immunocompromised e.g. HIV/AIDS, DM, RA, OA, unprotected sex.
Common organism for septic arthritis
S.aureus.
Risk factors for gout
High purine diet e.g. red meat, beer, seafood. CKD HTN Tumour lysis syndrome. Diuretics.
Triggers for gout
Infection, trauma/injury, dehydration, alcohol binge, surgery.
Blood tests in pseudogout.
High Ca Low Mg Low phosphate High iron Low parathyroid.
Gene associated with seronegative arthropathies
HLA B27
Diseases with a positive rheumatoid factor result
Sjogren's syndrome Felty's syndrome Rheumatoid arthritis Mixed connective tissue disease SLE in <40% Systemic sclerosis in 30%
Diseases with a positive Anti-CCP
RA
Diseases with a positive ANA
SLE
Autoimmune hepatitis
Sjogren’s syndrome
Systemic sclerosis.
Name 2 large, medium and small vessel vasculitis’
Large = giant cell arteritis / polymyalgia rheumatica, Takyasu's arteritis. Medium = Polyarteritis nodosa, Kawasaki's Small = Churg-Strauss, Granulomatosis with polyangiitis, Henoch-Schonlein purpura.
Common demographic of GCA patient
Over 55yr old female with polymyalgia rheumatic/symptoms of PMR.
Complication of GCA
Aortic aneurysms
Blindness
S+S of GCA
Symptoms:
Recent onset headache, scalp tenderness (e.g. on combing), jaw claudication, transient diplopia, SOB.
Systemic symptoms = malaise, myalgia, fever.
Features of polymyalgia rheumatica (ache, joint stiffness in morning)
O/E:
Temporal artery tenderness, nodularity.
Unequal temporal artery pulse.
2 ways of visual loss in GCA
Amorousis fugax
Anterior ischaemic optic neuropathy
Investigations of GCA
Raised ESR. If >50mm/hr and tenderness on palpation do a biopsy.
Temporal artery biopsy. Will show granulomatous inflammation, multinucleate giant cells and intimal hypertrophy.
Also CRP (high), FBC (high plts), high ALT and ALP.
1 single management for GCA
Prednisolone + aspirin + osteoporosis prevention.
Consider immunosuppressant if resistant e.g. methotrexate.
Demographic of Takyasu’s arteritis patient
Japanese female less than 50yrs old
Pathophysiology of Takyasu’s arteritis
Chronic progressive granulomatous inflammation leading to stenosis, thrombosis, occlusion, dilation and aneurysms.
Presentation of Takyasu’s arteritis
- Systemic stage of symptoms such as fever, fatigue, myalgia, malaise.
- Occlusive stage with symptoms dependent on area of ischaemia:
Limb claudication, chest pain, HTN (renal), TIA, Abdo pain.
O/E: Unilateral absent radial, brachial and carotid pulse. Bruits Unequal BP (>10mmHg) Aortic regurgitate murmur
1 single investigation of Takayasu’s (above all others)
CT angiography to show narrowing + occlusion.
Also raised CRP, ESR
Management of Takyasu’s
Steroid (e.g. pred) + aspirin + bone protection.
Long term can consider TNF-alpha inhibitor or methotrexate if resistant disease.
Disease associated with Polyarteritis nodosa
Hepatits B (hence incidence decreasing with vaccine)
Pathology and symptoms in Polyarteritis nodosa
- Necrotising arteritis of medium/small vessels, no vasculitis of arterioles, capillaries or venules and ANCA -ve. Most spare lungs.
- Leads to aneurysms, thrombi and infarction of MEDIUM VESSELS.
- Systemic features such as fever, weight loss, headache and myalgia. NO pulmonary involvement.
- High diastolic blood pressure
- Skin - purpura, ‘punched out’ necrotic ulcers
- CNS - Mononeuritis multiplex (painful, asymmetrical sensory and motor neuropathy), paraesthesia.
- GI - postprandial abdo pain.
- S+S of hepatitis B.
Investigations and results for PAN
High WCC, low Hb, high platelets
High ESR and CRP
Test for ANCA (should be -ve)
∆ by either
- Angiography = Microaneurysms and focal constriction - rosary sign.
- Biopsy of vessel = leukocyte infiltration and focal segmental transmural necrotising inflammation.
Management of PAN
Pred and DMARD e.g. cyclophosphamide, treat any Hep B
Kids can be given IVIG and aspirin.
Microscopic polyangiitis
Rapid progressive necrotising vasculitis. Glomerulonephritis and pulmonary haemorrhage.
p-ANCA positive.
Give them prednisolone and cyclophosphamide if I can ever remember this shitty condition.
Got problems with my throat, breathing and urine….? haemoptyisis and haematuria
Granulomatosis with Polyangiitis.
Triad of pathology in granulomatosis with polyangiitis
ENT
LUNG
KIDNEY
Is granulomatosis with polyangiitis ANCA pos or neg
POSITIVE
Presentation of granulomatosis with polyangiitis and Mx
ENT = sinus pain, saddle nose deformity, nasal septum perforation, stridor. Lung = SOB, cough, haemoptysis, rhonchi. Kidney = HTN, oedema, glomerulonephritis. Ocular = red, pain, bilateral periorbital oedema, diplopia. Cutaneous = palpable purpura and petechiae. MSK = arthralgia, joint swelling CNS = numb, weakness.
Mx = corticosteroids (e.g. methylprednisolone + prednisolone) and cyclophosphamide.
Difference between Osteopenia and Osteoporosis
Both are decrease in bone mineral density, however, osteopenia is not as severe.
Osteopenia DEXA T score = -1 to -2.5
Osteoporosis DEXA T score = less than -2.5.
Pathophysiology of decreased BMD (osteopenia and osteoporosis)
- Decreased bone mass and abnormal bone architecture causes low bone strength and increase in the bone’s fragility (increased risk of fractures).
- Increased bone resorption by osteoclasts and less dynamic bone synthesis by osteoblasts.
Where do osteoporotic fractures occur
Vertebral crush #
Distal radius wrist #
Proximal femur hip #
Pelvic #
RFx for osteoporosis
Steroids / Cushing’s
Hyperparathyroidism, hyperthyroidism, hypocalcaemia
Alcohol and tabacco
Thin (BMI <19)
Testerosterone low e.g in anti-androgens for prostate cancer.
Early menopause- FEMALE!!
Renal disease
Erosive inflammatory diseases e.g. metastasis, myeloma.
Dietary (malnutrition)
CFx of osteoporosis
Normal - present with fracture.
Back pain, kyphosis, impaired gait.
Ix low bone mineral density
DEXA scan!
Biomarkers of bone turnover e.g. P1NP.
Bloods = 25-hydroxy vitamin D, total and corrected calcium, TFT, LFT (ALP), PTH, phosphate.
CALCULATE FRAX SCORE!!
Different results of a DEXA scan
T score = difference between the pt’s BMD and the mean BMD value for young adults. Osteoporosis < -2.5
Z score = number of standard deviation above/belows age-matched BMD. Secondary osteoporosis < -1.5
Management of low bone mineral density
- ASSESS RISK WITH FRAX SCORE
- Lifestyle advice - regular exercise e.g. walking, balanced diet, quit smoking, alcohol consumption within recommended limits, fall prevention, signpost to support and information.
- Bisphosphonate - to be taken with TAP water, remain upright for 30mins after ingestion e.g. alendronic acid. Take for at least 5yrs.
- Calcium and vitamin D supplementation e.g. Calciferol.
- Denosumab.
- Teriparatide if severe.
Name some medications which can increase risk of osteoporosis
SSRI
PPI
Anticonvulsants e.g. Carbamazepine
Steroids
Good drug for postmenopausal women with low BMD
Denosumab = RANKL inhibitor, inhibits osteoclast formation and function.
Normal T score on DEXA scan
greater or equal to -1.
Boney profile blood test
Calcium, phosphate, ALP and parathyroid hormone.
SE of bisphosphonates
gastritis oesophagitis oesophageal ulcers dizziness and vertigo osteonecrosis of the jaw joint swelling
Pathophysiology of osteomalacia and difference between it and Ricket’s
Incomplete mineralisation of the bone matrix in adulthood causes softening of bone (growth plates have closed).
Rickets = poor mineralisation of epiphyseal growth plate cartilage in children.
(same process for each but different areas affected).
Causes and risk factors for osteomalacia
Vitamin D deficiency. RFx for which are housebound, chronic renal failure, anti-convulsants, malabsorption (Coeliac), anticonvulsants e.g. carbamazepine.
Renal disease + osteomalacia
Renal osteodystrophy
CFx of osteomalacia
S+S of vitamin D deficiency! Diffuse bone pain and bone tenderness esp back and hips. Fatigue and depression. Proximal muscle weakness Muscle fasiculations Severe - waddling gait.