Rheum Flashcards
What is the cause of discoid lupus?
Follicular keratin plugs
What is the treatment of discoid lupus?
Topical steroids –> hydroxychloroquine
Which antibodies are most specific for SLE?
Anti-SM
Anti-dsDNA
Which antibody is most sensitive for SLE
ANA
Why are C3 and C4 low during active lupus?
Formation of immune complexes causes consumption of complement
What is the pathogenesis of SLE?
Dysregulation of IgD
What is the treatment of SLE?
Hydroxychloroquine maintenance therapy
Internal organ involvement –> AZA, CYC, ritux
Prednisolone to induce remission
Which inflammatory markers are used to monitor SLE?
ESR
As CRP may be normal during active disease; if raised may indicate underlying infection
Apart from ESR, how else is SLE monitored?
Low complement
Anti-dsDNA titres
What antibody is associated specifically with neonatal lupus erythematosus?
Anti-Ro
What are the complications/features of congenital lupus?
Heart block
Skin rashes
Hepatosplenomegaly
What percentage of psoriasis patients develop arthritis?
10-20%
What are the 5 types of psoriatic arthritis?
Symmetrical (similar to RA) Asymmetrical oligo Sacroilitis DIP joint disease Arthritis mutilans
What are other signs of psoriatic arthropathy?
Tenosynovitis
Dactylitis
Enthesitis
Nail pitting and onycholysis
What are the X-Ray appearances of psoriatic arthritis?
Co-existence of erosive changes and new bone formation
Periostitis
Pencil in cup appearance
What is rheumatoid factor?
IgM against IgG
Which HLA is RA associated with?
DR4
Especially Felty’s syndrome
What is Felty’s syndrome?
RA
Splenomegaly
Neutropaenia
What are the X-Ray features of RA?
Loss of joint space
Juxta-articular osteoporosis
Soft tissue swelling
Late - periarticular erosions, subluxation
What percentage of normal people have +ve HLA-B27?
10%
What percentage of ankylosing spondylitis patients have +ve HLA-B27?
90%
What is Schober’s sign?
An increase of less than 5cm on anterior spinal flexion when measuring the distance from 10cm above and 5cm below the left posterior iliac spine
What are the X-Ray features of ankylosing spondylitis?
Bamboo spine
Sacroilitis (subchondral erosions, sclerosis of vertebral corners)
Squaring of vertebrae
Syndesmophytes
What is bamboo spine?
Ossification of outer fibres of annulus fibrosus
What are the complications of ankylosing spondylitis?
Apical fibrosis Anterior uveitis Aortic regurgitation Achilles tendonitis AV node block Amyloidosis
What is the treatment of ankylosing spondylitis?
Exercise and physio
NSAIDs
DMARDS if peripheral joint involvement
TNF inhibitors - do not improve radiological progression
What is the most common organism causing septic arthritis?
S.aureus
Young sexually active adults - neisseria gonorrhoea
What is the cause of reactive arthritis?
Post STI form most common form in men, post-dysenteric form equal sex incidence
Shigella flexneri, salmonella typhi/enteritidis, yersinia, campylobacter, chlamydia trachomaatis
What is the triad of reactive arthritis?
Urethritis
Conjunctivitis/anterior uveitis
Arthritis - asymmetrical, lower limbs
Also dactylitis, circinate balanitis, keratoderma blenorrrhagica
What is the prognosis of reactive arthritis?
Symptoms last 4-6 months
25% have recurrent episodes, 10% chronic disease
In gout, where are the urate crystals deposited?
Superficial portions of the articular cartilage
What is the most common cause of gout?
Decreased excretion of uric acid - diuretics, CKD, lead toxicity
What are other causes of gout?
Increased production of uric acid - myeloproliferative disorder, cytotoxic drugs, severe psoriasis
Lesch-Nyhan syndrome
What are the X-Ray features of gout?
Joint effusion "Punched out" erosions with sclerotic margins in a juxta-articular distribution, often with overhanging edges Eccentric erosions No periarticular osteopenia Soft tissue tophi
What is the double contour sign in gout?
Hyperechoic irregular band over the superficial margin of the joint cartilage, produce by deposition of monosodium urate crystals on the surface of the hyaline cartilage
Where do calcium pyrophosphate crystals deposit in pseudogout?
The middle layer of the hyaline cartilage, parallel to the bony cortex as a hyper-echoic irregular line embedded in the cartilage (with a normal hyaline cartilage surface)
What are risk factors for pseudogout if it develops at a younger age?
Haemochromatosis Hyperparathyroidism Low magnesium Low phosphate Acromegaly Wilson's disease
What is seen on joint aspiration in pseudogout?
Weakly positive birefringent rhomboid shaped crystals
What are the 3 types of systemic sclerosis?
Limited cutaneous
Diffuse cutaneous
Scleroderma
What are the features of limited cutaneous systemic sclerosis?
Raynaud’s may be first sign
Scleroderma of face an distal limbs
Subtype: CREST syndrome (calcinosis, Raynaud’s, oesophageal dysmotility, sclerodactyly, telangiectasia)
What are the features of diffuse cutaneous systemic sclerosis?
Scleroderma of trunk and proximal limbs
Respiratory (ILD and PAH) involvement, renal disease
Which antibodies are associated with systemic sclerosis?
Limited cutaneous: ACA
Diffuse cutaneous: Anti-Scl-70
Both: ANA in 90%, RF in 30%
What are the features of antiphospholipid syndrome?
Venous and arterial thombosis
Recurrent foetal loss
Thrombocytopenia
Livedo reticularis
Why is APTT high in APS?
Ex vivo reaction of the lupus anticoagulant autoantibodies with phospholipids involved in the coagulation cascade
What is the treatment of antiphospholipid syndrome?
Primary thromboprophylaxis - low dose aspirin
Secondary thromboprophylaxis - lifelong warfarin, target INR 2-3
Recurrent VTE on warfarin - add low dose aspirin, target INR 3-4
What are the features of dermatomyositis?
Heliotrope rash around the eyelids
Gottron’s papules
Fatigue and weakness
Which antibodies are associated with dermatomyositis?
ANA most common (60%)
Anti-Mi2 most specific (only seen in 25%)
How is dermatomyositis diagnosed?
Elevated CK
EMG
Muscle biopsy
What is Sharp’s syndrome?
Mixed connective tissue disease
What are the features of mixed connective tissue disease?
Raynaud’s
Polyarthralgia
Myalgia
Dactylitis
Also photosensitive rash, scleroderma-like changes, oesophageal dysfunction, pleurisy/PAH/ILD, glomerulonephritis
Which antibodies are positive in mixed connective tissue disease?
Anti-U1 ribonucleotide antibodies
ANA
What is Raynaud’s disease?
Exaggerated vasoconstrictive response of the digital arteries and cutaneous arteriole to the cold or emotional stress
What are the secondary causes of Raynaud’s?
CTDs Leukaemia Type 1 cryoglobulinaemia Vibrating tools COCP Cervical rib
Which features of Raynaud’s suggest underlying CTDs?
Onset after 40
Unilateral
Rash, digital ulcers, calcinosis
Autoantibodies
What is the management of Raynaud’s?
CCB - nifedipine
2nd line IV prostacyclin infusion (lasts several weeks/months)
What is the cause of Marfan’s syndrome?
Mutation on FBN1 gene on chromosome 15 that codes for the protein fibrillin 1.
What are the eye symptoms of Marfan’s?
Supero-temporal ectopia lentis
Blue sclera
Myopia
What is dural ectasia?
Ballooning of the dural sac at the lumbrosacral level
60% Marfan’s patients
Lower back pain, headaches, bladder and bowel dysfunction
What are the cardiac symptoms of Marfan’s?
MV prolapse
Aortic dissection
What is the management of Marfan’s?
Regular ECHOs
BB/ACEIs
What is the cause of polymyositis?
T cell mediated cytotoxic process against muscle fibres
Idiopathic, CTD, malignancy
How is polymyositis diagnosed?
Elevated CK, LDH, aldolase, AST, ALT
EMG
Muscle biopsy
Which antibodies are associated with polymyositis?
Anti-synthetase
Anti-Jo 1 (associated with more severe form associated with lung involvement)
What is polyarteritis nodosa?
Vasculitis of medium sized arteries leading to aneurysm formation
What is PAN associated with?
Hepatitis B
Middle aged men
What are the features of PAN?
Fever etc Mononeuritis multiplex Hypertension Livedo reticularis Haematuria and renal failure
Which antibody is associated with PAN?
pANCA in 20%
What is familial mediterranean fever and who gets it?
Autosomal recessive
Presents in 2nd decade
Turkish, Armenian, Arabic descent
What are the features of FMF?
Pyrexia Abdo pain from peritonitis Pleurisy Pericarditis Arthritis Erysipeloid rash
What is the management of FMF?
Colchicine
What is the cause and pathophysiology of Langerhans Cell Histiocytosis?
Abnormal proliferation of dendritic cells/histiocytes
Formation of multiple granulomas
What are the features of Langerhans Cell Histiocytosis?
Bone pain (skull or proximal femur)
Rash
Recurrent otitis media/mastoiditis
What is seen on electron microscopy in LCH?
Tennis racket shape Birbeck granules
What are the features of Still’s disease?
Arthralgia
Swinging pyrexia that peaks early evening
Salmon pink maculopapular rash
Lymphadenopathy
What is the diagnostic criteria of Still’s disease?
Yamaguchi
How is Still’s disease diagnosed?
RF and ANA negative
Elevated ferritin
What is osteopetrosis?
Failure of osteoclastic bone resorption –> cortical thickening and sclerosis –> thick and brittle bones
Autosomal dominant
What are the features of osteopetrosis?
Fractures
How is osteopetrosis diagnosed?
XR: symmetrical and diffuse skeletal sclerosis - stone bone
Normal Ca, phosphate, ALP, PTH
What is the cause of osteogenesis imperfecta?
Autosomal dominant inheritance of mutation in gene coding for type 1 collagen
Decreased synthesis of pro-alpha 1 or pro-alpha 2 collagen polypeptides
What are the features of osteogenesis imperfecta?
Fractures
Blue sclerae
Deafness secondary to otosclerosis
Dental imperfections
What types of collagen form cell surfaces and hairs, and the basal lamina?
Cell surfaces, hairs - Collagen type 5 - Classic Ehlers-Danlos
Basal lamina - Type 4 - Alport’s and Goodpasture’s syndrome
What is the cause of Paget’s disease?
Excessive osteoclastic resorption followed by increased osteoclastic activity - uncontrolled bone turnover
How is Paget’s disease diagnosed?
Normal Ca, PO4, PTH
Isolated raised ALP
What is the treatment of Paget’s disease?
Bisphosphonates
What are the features of spinal stenosis?
Gradual onset uni/bilateral leg pain, with or without back pain
Numbness and weakness
Worse on walking, resolves when sitting/leaning forwards/crouching down
Normal examination
What is osteomalacia?
Softening of the bones secondary to low vitamin D
What are the symptoms of osteomalacia?
Bone pain
Fractures
Proximal myopathy
How is osteomalacia diagnosed?
High ALP
Low calcium and phosphate
Translucent bands (Looser’s zones) on X-Ray
What are the complications of Paget’s disease?
Cranial nerve entrapment Bone sarcoma Fractures Skull thickening High output cardiac failure
What are the risk factors for avascular necrosis of the hip?
Long term steroid use
Chemotherapy
Alcohol excess
Trauma
What is seen on X-Ray in avascular necrosis of the hip?
Osteopenia
Microfractures
Crescent sign (collapse of the articular surface)
How do bisphosphonates work?
Analogues of pyrophosphate, a molecular which decreases demineralization in bone
Inhibits osteoclasts by reducing recruitment and promoting apoptosis
What are 3 side effects of bisphosphonates?
Oesophagitis
Osteonecrosis of the jaw
atypical stress fractures of the proximal femoral shaft
What type of retinopathy is seen in hydroxychloroquine use?
Bull’s eye
How does sulfasalazine work?
Prodrug for 5-ASA
Decreases neutrophil chemotaxis, suppresses proliferation of lymphocytes and pro-inflammatory cytokines
In which patients should use of sulfasalazine be avoided?
G6P deficiency
Allergy to aspirin/sulphonamides (cross-sensitivity)
What are 6 side effects of sulfasalazine?
Oligospermia Stevens-Johnson syndrome Pneumonitis Myelosuppression Heinz body/megaloblastic anaemia Coloured tears
What are the side effects of leflunomide?
Diarrhoea Hypertension WL Peripheral neuropathy Myelosuppression Pneumonitis
What are the rules when stopping leflunomide?
Wash out period of a year
Requires co-administration of cholestyramine
In what condition are anti-yo antibodies seen?
Patients with breast cancer and paraneoplastic syndrome
Associated with cerebellar degeneration and ataxia
What is DeQuervain’s tenosynovitis?
Sheath containing the extensor pollicis brevis and abductor pollicis longus tendons is inflamed
What are the features of De Quervain’s tenosynovitis?
Pain on radial side of wrist
Tenderness over radial styloid process
Painful abduction of thumb against resistance
Finkelstein’s test - examiner pulls thumb in ulnar deviation and longitudinal traction - causes pain over radial styloid process
Which nerve is compressed in carpal tunnel syndrome?
Median
What are 6 causes of carpal tunnel syndrome?
Pregnancy Lunate fracture RA Hypothyroid Acromegaly Idiopathic
What is seen on examination in Carpal Tunnel syndrome?
Tinel’s and Phalen’s sign
Weakness of thumb abduction (abductor pollicis longus)
Wasting of thenar eminence
What is surgical decompression of Carpal tunnel syndrome?
Division of flexor retinaculum
What are the general features of prolapsed disc?
Dermatomal leg pain associated with neurological deficits
Leg pain > back pain
Pain worse when standing
Which vertebral disc is prolapsed when a positive femoral stretch test is seen, with weak quadriceps, reduced knee reflex, and sensory loss over anterior knee?
L3 or L4
What is seen in L5 disc prolapse?
Sensory loss over dorsum of foot
Weakness in foot and big toe dorsiflexion
Reflexes intact
Positive sciatic nerve stretch test
What is seen in S1 disc prolapse?
Positive sciatic nerve stretch test
Weakness in plantar flexion of foot
Reduced ankle reflex
Sensory loss over posterolateral aspect of leg and lateral aspect of foot
What level of rheumatoid factor and ANA titre is significant?
> 1:160
>1:80
What skin lesions are seen in Behcet’s disease?
Erythema nodosum
Acneiform
Migratory thrombophlebitis
Vasculitic
What is reflex sympathetic dystrophy?
Complex regional pain syndrome
Disproportionate pain secondary to injury/surgery
Skin changes from autonomic dysfunction