Rheumatology Flashcards
what is systemic sclerosis
Systemic sclerosis is a condition of unknown aetiology characterised by hardened, sclerotic skin and other connective tissues. It is four times more common in females.
Limited cutaneous systemic sclerosis
Raynaud’s may be first sign
scleroderma affects face and distal limbs predominately
associated with anti-centromere antibodies
a subtype of limited systemic sclerosis is CREST syndrome: Calcinosis, Raynaud’s phenomenon, oEsophageal dysmotility, Sclerodactyly, Telangiectasia
What is CREST
Calcinosis Raynaud's phenomenon oEsophageal dysmotility Sclerodactyly Telangiectasia
Diffuse cutaneous systemic sclerosis
scleroderma affects trunk and proximal limbs predominately
associated with scl-70 antibodies
the most common cause of death is now respiratory involvement, which is seen in around 80%: interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH)
other complications include renal disease and hypertension
poor prognosis
Scleroderma (without internal organ involvement)
tightening and fibrosis of skin
may be manifest as plaques (morphoea) or linear
Systemic sclerosis antibodies
ANA positive in 90%
RF positive in 30%
anti-scl-70 antibodies associated with diffuse cutaneous systemic sclerosis
anti-centromere antibodies associated with limited cutaneous systemic sclerosis
What is pseudogout?
Pseudogout is a form of microcrystal synovitis caused by the deposition of calcium pyrophosphate dihydrate crystals in the synovium. For this reason, it is now more correctly termed acute calcium pyrophosphate crystal deposition disease.
Risk factors for pseudogout
Pseudogout is strongly associated with increasing age. Patients who develop pseudogout at a younger age (e.g. < 60 years) usually have some underlying risk factor, such as: haemochromatosis hyperparathyroidism low magnesium, low phosphate acromegaly, Wilson's disease
Features of pseudogout
knee, wrist and shoulders most commonly affected
joint aspiration: weakly-positively birefringent rhomboid-shaped crystals
x-ray: chondrocalcinosis
in the knee this can be seen as linear calcifications of the meniscus and articular cartilage
Management of pseudogout
aspiration of joint fluid, to exclude septic arthritis
NSAIDs or intra-articular, intra-muscular or oral steroids as for gout
Features of drug induced lupus
arthralgia
myalgia
skin (e.g. malar rash) and pulmonary involvement (e.g. pleurisy) are common
ANA positive in 100%, dsDNA negative
anti-histone antibodies are found in 80-90%
anti-Ro, anti-Smith positive in around 5%
Most common causes of drug induced lupus
procainamide
hydralazine
Least common causes of drug induced lupus
isoniazid
minocycline
phenytoin
What is polyarteritis nodosa
Polyarteritis nodosa (PAN) is a vasculitis affecting medium-sized arteries with necrotizing inflammation leading to aneurysm formation. PAN is more common in middle-aged men and is associated with hepatitis B infection.
Features of polyarteritis nodosa
fever, malaise, arthralgia
weight loss
hypertension
mononeuritis multiplex, sensorimotor polyneuropathy
testicular pain
livedo reticularis
haematuria, renal failure
perinuclear-antineutrophil cytoplasmic antibodies (ANCA) are found in around 20% of patients with ‘classic’ PAN
hepatitis B serology positive in 30% of patients
SLE antibodies
99% are ANA positive
this high sensitivity makes it a useful rule out test, but it has low specificity
20% are rheumatoid factor positive
anti-dsDNA: highly specific (> 99%), but less sensitive (70%)
anti-Smith: highly specific (> 99%), sensitivity (30%)
also: anti-U1 RNP, SS-A (anti-Ro) and SS-B (anti-La)
SLE monitoring investigations
Inflammatory markers
ESR is generally used
during active disease the CRP may be normal - a raised CRP may indicate underlying infection
complement levels (C3, C4) are low during active disease (formation of complexes leads to consumption of complement)
anti-dsDNA titres can be used for disease monitoring (but note not present in all patients)
Mechanism of action of methotrexate
Methotrexate is an antimetabolite that inhibits dihydrofolate reductase, an enzyme essential for the synthesis of purines and pyrimidines. It is considered an ‘important’ drug as whilst it can be very effective in controlling disease the side-effects may be potentially life-threatening - careful prescribing and close monitoring is essential.
Indications for Methotrexate
nflammatory arthritis, especially rheumatoid arthritis
psoriasis
some chemotherapy acute lymphoblastic leukaemia
Adverse effects of methotrexate
mucositis myelosuppression pneumonitis pulmonary fibrosis liver fibrosis hepatotoxicity
Pregnancy and methotrexate
women should avoid pregnancy for at least 6 months after treatment has stopped
the BNF also advises that men using methotrexate need to use effective contraception for at least 6 months after treatment
Prescribing methotrexate
methotrexate is a drug with a high potential for patient harm. It is therefore important that you are familiar with guidelines relating to its use
methotrexate is taken weekly, rather than daily
FBC, U&E and LFTs need to be regularly monitored. The Committee on Safety of Medicines recommend ‘FBC and renal and LFTs before starting treatment and repeated weekly until therapy stabilised, thereafter patients should be monitored every 2-3 months’
folic acid 5mg once weekly should be co-prescribed, taken more than 24 hours after methotrexate dose
the starting dose of methotrexate is 7.5 mg weekly (source: BNF)
only one strength of methotrexate tablet should be prescribed (usually 2.5 mg)
Methotrexate interactions
avoid prescribing trimethoprim or co-trimoxazole concurrently - increases risk of marrow aplasia
high-dose aspirin increases the risk of methotrexate toxicity secondary to reduced excretion
What is Behcet’s syndrome
Behcet’s syndrome is a complex multisystem disorder associated with presumed autoimmune-mediated inflammation of the arteries and veins. The precise aetiology has yet to be elucidated however. The classic triad of symptoms are oral ulcers, genital ulcers and anterior uveitis
Epidemiology of Behcet’s syndrome
more common in the eastern Mediterranean (e.g. Turkey)
more common in men (complicated gender distribution which varies according to country. Overall, Behcet’s is considered to be more common and more severe in men)
tends to affect young adults (e.g. 20 - 40 years old)
associated with HLA B51- more specifically HLA B51, a split antigen of HLA B5
around 30% of patients have a positive family history
Features of Behcet’s syndrome
classically: 1) oral ulcers 2) genital ulcers 3) anterior uveitis
thrombophlebitis and deep vein thrombosis
arthritis
neurological involvement (e.g. aseptic meningitis)
GI: abdo pain, diarrhoea, colitis
erythema nodosum
Diagnosis of Behcet’s syndrome
no definitive test
diagnosis based on clinical findings
positive pathergy test is suggestive (puncture site following needle prick becomes inflamed with small pustule forming)
Causes of Osteomalacia
vitamin D deficiency malabsorption lack of sunlight diet chronic kidney disease drug induced e.g. anticonvulsants inherited: hypophosphatemic rickets (previously called vitamin D-resistant rickets) liver disease: e.g. cirrhosis
Features of Osteomalacia
bone pain
bone/muscle tenderness
fractures: especially femoral neck
proximal myopathy: may lead to a waddling gait
Investigations of osteomalacia
bloods
low vitamin D levels
low calcium, phosphate (in around 30%)
raised alkaline phosphatase (in 95-100% of patients)
x-ray
translucent bands (Looser’s zones or pseudofractures
Treatment of osteomalacia
vitamin D supplmentation
a loading dose is often needed initially
calcium supplementation if dietary calcium is inadequate
Bone profile
osteoporosis
Normal Ca
Normal phosphate
Normal ALP
Normal PTH
Bone Profile
Osteomalacia
Decreased Ca
Decreased phosphate
Increased ALP
Increased PTH
Bone Profile
Primary hyperparathyroidism (→ osteitis fibrosa cystica)
IncreasedCa
Decreased phosphate
Increased ALP
Increased PTH
Bone Profile
Chronic kidney disease (→ secondary hyperparathyroidism)
Decreased Ca
Increased phosphate
Increased ALP
Increased PTH
Bone profile
Paget’s disease
Normal Ca
Normal phosphate
Increased ALP
Normal PTH
Bone Profile
Osteopetrosis
Normal Ca
Normal phosphate
Normal ALP
Normal PTH
What is Sjogren’s syndrome
autoimmune disorder affecting exocrine glands resulting in dry mucosal surfaces. It may be primary (PSS) or secondary to rheumatoid arthritis or other connective tissue disorders, where it usually develops around 10 years after the initial onset. Sjogren’s syndrome is much more common in females (ratio 9:1). There is a marked increased risk of lymphoid malignancy (40-60 fold).
Features of Sjogren’s syndrome
dry eyes: keratoconjunctivitis sicca dry mouth vaginal dryness arthralgia Raynaud's, myalgia sensory polyneuropathy recurrent episodes of parotitis renal tubular acidosis (usually subclinical)
investigations for Sjogren’s syndrome
rheumatoid factor (RF) positive in nearly 50% of patients
ANA positive in 70%
anti-Ro (SSA) antibodies in 70% of patients with PSS
anti-La (SSB) antibodies in 30% of patients with PSS
Schirmer’s test: filter paper near conjunctival sac to measure tear formation
histology: focal lymphocytic infiltration
also: hypergammaglobulinaemia, low C4
Management of Sjogren’s syndrome
artificial saliva and tears
pilocarpine may stimulate saliva production
What is polymyositis
inflammatory disorder causing symmetrical, proximal muscle weakness
thought to be a T-cell mediated cytotoxic process directed against muscle fibres
may be idiopathic or associated with connective tissue disorders
associated with malignancy
dermatomyositis is a variant of the disease where skin manifestations are prominent, for example a purple (heliotrope) rash on the cheeks and eyelids
typically affects middle-aged, female:male 3:1
Features of polymyositis
proximal muscle weakness +/- tenderness Raynaud's respiratory muscle weakness interstitial lung disease: e.g. fibrosing alveolitis or organising pneumonia dysphagia, dysphonia
Investigations for polymyositis
elevated creatine kinase
other muscle enzymes (lactate dehydrogenase (LDH), aldolase, AST and ALT) are also elevated in 85-95% of patients
EMG
muscle biopsy
anti-synthetase antibodies
anti-Jo-1 antibodies are seen in pattern of disease associated with lung involvement, Raynaud’s and fever
Investigations of dermatomysositis
elevated creatine kinase
EMG
muscle biopsy
ANA positive in 60%
anti-Mi-2 antibodies are highly specific for dermatomyositis, but are only seen in around 25% of patients
anti-Jo-1 antibodies are not commonly seen in dermatomyositis - they are more common in polymyositis where they are seen in a pattern of disease associated with lung involvement, Raynaud’s and fever
Management of dermatomyositis
prednisolone
Methotrexate side effects
Myelosuppression
Liver cirrhosis
Pneumonitis
Sulfasalazine side effects
Rashes
Oligospermia
Heinz body anaemia
Interstitial lung disease
Leflunomide side effects
Liver impairment
Interstitial lung disease
Hypertension
Hydroxychloroquine side effects
Retinopathy
Corneal deposits
Prednisolone side effects
Cushingoid features Osteoporosis Impaired glucose tolerance Hypertension Cataracts
Gold side effects
Proteinuria
Penicillamine side effects
Proteinuria
Exacerbation of myasthenia gravis
Etanercept side effects
Demyelination
Reactivation of tuberculosis
Infliximab side effects
Reactivation of tuberculosis
Adalimumab side effects
Reactivation of TB
Rituximab side effects
Infusion reactions are common
NSAIDs (e.g. naproxen, ibuprofen) side effects
Bronchospasm in asthmatics
Dyspepsia/ gastric ulceration
Examples of ANCA associated vasculitis
granulomatosis with polyangiitis
eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
microscopic polyangiitis
Common features of ANCA associated vasculitis
renal impairment caused by immune complex glomerulonephritis → raised creatinine, haematuria and proteinuria respiratory symptoms dyspnoea haemoptysiis systemic symptoms fatigue weight loss fever vasculitic rash: present only in a minority of patients ear, nose and throat symptoms sinusitis
First line investigations for ANCA associated vasculitis
urinalysis for haematuria and proteinuria
bloods:
urea and creatinine for renal impairment
full blood count: normocytic anaemia and thrombocytosis may be seen
CRP: raised
ANCA testing (see below)
chest x-ray: nodular, fibrotic or infiltrative lesions may be seen
cANCA target
Serine proteinase 3 (PR3)
cANCA in disease- levels
+ve in Granulomatosis with polyangiitis (90%)
Low in eosinophilic granulomatosis with polyangiitis
40% of microscopic polyangiitis
some relationship between cANCA levels and disease management.
pANCA target
myeloperoxidase (MPO)
pANCA in disease - levels
+ve in Granulomatosis with polyangiitis (25%)
+ve in eosinophilic granulomatosis with polyangiitis (50%)
75% of microscopic polyangiitis
Diseases associated with pANCA
Ulcerative colitis (70%)
Primary sclerosing cholangitis (70%)
Anti-GBM disease (25%)
Crohn’s disease (20%)
pANCA monitoring
Can’t be used for disease monitoring
Haematogenous osteomyelitis
results from bacteraemia
is usually monomicrobial
most common form in children
vertebral osteomyelitis is the most common form of haematogenous osteomyelitis in adults
risk factors include: sickle cell anaemia, intravenous drug user, immunosuppression due to either medication or HIV, infective endocarditis
non-haematogenous osteomyelitis
results from the contiguous spread of infection from adjacent soft tissues to the bone or from direct injury/trauma to bone
is often polymicrobial
most common form in adults
risk factors include: diabetic foot ulcers/pressure sores, diabetes mellitus, peripheral arterial disease
Microbiology of osteomyelitis
Staph. aureus is the most common cause except in patients with sickle-cell anaemia where Salmonella species predominate
Management of osteomyelitis
flucloxacillin for 6 weeks
Clindamycin if pen allergic
ANA antibodies
SLE
diffuse cutaneous systemic sclerosis
Limited cutaneous systemic sclerosis
Sjogren’s syndrome
Anti-Jo-1 antibodies
polymyositis
Anti-cyclic citrullinated peptide antibody
Rheumatic Athritis
What is Raynaud’s disease
Raynaud’s phenomenon is characterised by an exaggerated vasoconstrictive response of the digital arteries and cutaneous arteriole to the cold or emotional stress. It may be primary (Raynaud’s disease) or secondary (Raynaud’s phenomenon).
Raynaud’s disease typically presents in young women (e.g. 30 years old) with bilateral symptoms.
Secondary causes of Raynaud’s disease
connective tissue disorders scleroderma (most common) rheumatoid arthritis systemic lupus erythematosus leukaemia type I cryoglobulinaemia, cold agglutinins use of vibrating tools drugs: oral contraceptive pill, ergot cervical rib
Factors suggesting underlying connective tissue disease in Raynaud’s
onset after 40 years unilateral symptoms rashes presence of autoantibodies features which may suggest rheumatoid arthritis or SLE, for example arthritis or recurrent miscarriages digital ulcers, calcinosis very rarely: chilblains
Management of Raynaud’s
all patients with suspected secondary Raynaud’s phenomenon should be referred to secondary care
first-line: calcium channel blockers e.g. nifedipine IV prostacyclin (epoprostenol) infusions: effects may last several weeks/months
What is discoid lupus erythematous?
benign disorder generally seen in younger females. It very rarely progresses to systemic lupus erythematosus (in less than 5% of cases). Discoid lupus erythematosus is characterised by follicular keratin plugs and is thought to be autoimmune in aetiology
Features of discoid lupus erythematous
erythematous, raised rash, sometimes scaly
may be photosensitive
more common on face, neck, ears and scalp
lesions heal with atrophy, scarring (may cause scarring alopecia), and pigmentation
Management of discoid lupus erythematous
topical steroid cream
oral antimalarials may be used second-line e.g. hydroxychloroquine
avoid sun exposure
Osteopetrosis
also known as marble bone disease
rare disorder of defective osteoclast function resulting in failure of normal bone resorption
results in dense, thick bones that are prone to fracture
bone pains and neuropathies are common.
calcium, phosphate and ALP are normal
stem cell transplant and interferon-gamma have been used for treatment
Eye symptoms of Marfan’s
upwards lens dislocation (superotemporal ectopia lentis), blue sclera, myopia
Development Dysplasia of Hip
Often picked up on newborn examination
Barlow’s test, Ortolani’s test are positive
Unequal skin folds/leg length
Transient synovitis (irritable hip)
Typical age group = 2-10 years
Acute hip pain associated with viral infection
Commonest cause of hip pain in children
Perthe’s disease
Epidemiology
Perthes disease is a degenerative condition affecting the hip joints of children, typically between the ages of 4-8 years. It is due to avascular necrosis of the femoral head
Perthes disease is 5 times more common in boys. Around 10% of cases are bilateral
Perthes disease
Features
hip pain: develops progressively over a few weeks
limp
stiffness and reduced range of hip movement
x-ray: early changes include widening of joint space, later changes include decreased femoral head size/flattening
Slipped upper femoral epiphysis
Typical age group = 10-15 years
More common in obese children and boys
Displacement of the femoral head epiphysis postero-inferiorly
Bilateral slip in 20% of cases
May present acutely following trauma or more commonly with chronic, persistent symptoms
Slipped upper femoral epiphysis
Features
knee or distal thigh pain is common
loss of internal rotation of the leg in flexion
Juvenile idiopathic arthritis (JIA)
Preferred to the older term juvenile chronic arthritis, describes arthritis occurring in someone who is less than 16 years old that lasts for more than three months. Pauciarticular JIA refers to cases where 4 or less joints are affected. It accounts for around 60% of cases of JIA
Juvenile idiopathic arthritis (JIA)
Features
joint pain and swelling: usually medium sized joints e.g. knees, ankles, elbows
limp
ANA may be positive in JIA - associated with anterior uveitis
Septic Arthritis
Acute hip pain associated with systemic upset e.g. pyrexia. Inability/severe limitation of affected joint
What is pagets disease of the bone
Paget’s disease is a disease of increased but uncontrolled bone turnover. It is thought to be primarily a disorder of osteoclasts, with excessive osteoclastic resorption followed by increased osteoblastic activity. Paget’s disease is common (UK prevalence 5%) but symptomatic in only 1 in 20 patients. The skull, spine/pelvis, and long bones of the lower extremities are most commonly affected.
Pre-disposing factors of pagets disease
increasing age
male sex
northern latitude
family history
Clinical features of Pagets disease
older male with bone pain and an isolated raised ALP bone pain (e.g. pelvis, lumbar spine, femur) classical, untreated features: bowing of tibia, bossing of skull raised alkaline phosphatase (ALP) - calcium* and phosphate are typically normal other markers of bone turnover include: procollagen type I N-terminal propeptide (PINP), serum C-telopeptide (CTx), urinary N-telopeptide (NTx), and urinary hydroxyproline skull x-ray: thickened vault, osteoporosis circumscripta
Treatment of Pagets disease of the bone
(indicated with bone pain, skull/long bone deformity, fracture or peri-articular Pagets
bisphosphonate (either oral risedronate or IV zoledronate)
calcitonin is less commonly used now
Complications of Pagets disease of the bone
deafness (cranial nerve entrapment) bone sarcoma (1% if affected for > 10 years) fractures skull thickening high-output cardiac failure
Polymyositis
inflammatory disorder causing symmetrical, proximal muscle weakness
thought to be a T-cell mediated cytotoxic process directed against muscle fibres
may be idiopathic or associated with connective tissue disorders
associated with malignancy
dermatomyositis is a variant of the disease where skin manifestations are prominent, for example a purple (heliotrope) rash on the cheeks and eyelids
typically affects middle-aged, female:male 3:1
Features of polymyositis
proximal muscle weakness +/- tenderness Raynaud's respiratory muscle weakness interstitial lung disease: e.g. fibrosing alveolitis or organising pneumonia dysphagia, dysphonia
Investigations of polymyositis
elevated creatine kinase
other muscle enzymes (lactate dehydrogenase (LDH), aldolase, AST and ALT) are also elevated in 85-95% of patients
EMG
muscle biopsy
anti-synthetase antibodies
anti-Jo-1 antibodies are seen in pattern of disease associated with lung involvement, Raynaud’s and fever
Pre-disposing factors for Pseudogout
haemochromatosis
hyperparathyroidism
low magnesium, low phosphate
acromegaly, Wilson’s disease
Features of pseudogout
knee, wrist and shoulders most commonly affected
joint aspiration: weakly-positively birefringent rhomboid-shaped crystals
x-ray: chondrocalcinosis
in the knee this can be seen as linear calcifications of the meniscus and articular cartilage
Management of pseudogout
aspiration of joint fluid, to exclude septic arthritis
NSAIDs or intra-articular, intra-muscular or oral steroids as for gout
What is Schirmer’s test
filter paper near conjunctival sac to measure tear formation
SLE antibodies
ANA Anti-dsDNA Anti-Smith Rheumatoid factor anti-U1 RNP, SS-A (anti-Ro) and SS-B (anti-La)
Dermatomyositis antibodies
ANA
Anti- Mi-2
Sjogren’s antibodies
Rheumatoid factor
ANA
Anti-Ro (SSB)
Anti- La
Raloxifene
has been shown to prevent bone loss and to reduce the risk of vertebral fractures, but has not yet been shown to reduce the risk of non-vertebral fractures
has been shown to increase bone density in the spine and proximal femur
may worsen menopausal symptoms
increased risk of thromboembolic events
may decrease risk of breast cancer
what is stronium ranelate
‘dual action bone agent’ - increases deposition of new bone by osteoblasts (promotes differentiation of pre-osteoblast to osteoblast) and reduces the resorption of bone by inhibiting osteoclasts
concerns regarding the safety profile of strontium have been raised recently. It should only be prescribed by a specialist in secondary care
due to these concerns the European Medicines Agency in 2014 said it should only be used by people for whom there are no other treatments for osteoporosis
increased risk of cardiovascular events: any history of cardiovascular disease or significant risk of cardiovascular disease is a contraindication
increased risk of thromboembolic events: a Drug Safety Update in 2012 recommended it is not used in patients with a history of venous thromboembolism
may cause serious skin reactions such as Stevens Johnson syndrome
Mechanism of action for etanercept
acts as a decoy receptor for TNF-a
may reactivate TB
Mechanism of action for infliximab
Binds to TNF-a and prevents it binding to TNF receptors
May reactivate TB
Management of raynaurd’s
all patients with suspected secondary Raynaud's phenomenon should be referred to secondary care first-line: calcium channel blockers e.g. nifedipine IV prostacyclin (epoprostenol) infusions: effects may last several weeks/months
What is McArdle’s disease
autosomal recessive type V glycogen storage disease
caused by myophosphorylase deficiency
this causes decreased muscle glycogenolysis
Features of McArdle’s
muscle pain and stiffness following exercise
muscle cramps
myoglobinuria
low lactate levels during exercise
What is azathioprine
Azathioprine is metabolised to the active compound mercaptopurine, a purine analogue that inhibits purine synthesis. A thiopurine methyltransferase (TPMT) test may be needed to look for individuals prone to azathioprine toxicity.
Adverse effects of azathioprine
bone marrow depression
nausea/vomiting
pancreatitis
increased risk of non-melanoma skin cancer
A significant interaction may occur with allopurinol and hence lower doses of azathioprine should be used.
Azathioprine is generally considered safe to use in pregnancy.
Chondromalacia patellae
Softening of the cartilage of the patella
Common in teenage girls
Characteristically anterior knee pain on walking up and down stairs and rising from prolonged sitting
Usually responds to physiotherapy
Osgood-Schlatter disease
tibial apophysitis
Seen in sporty teenagers
Pain, tenderness and swelling over the tibial tubercle
Osteochondritis dissecans
Pain after exercise
Intermittent swelling and locking
Patellar subluxation
Medial knee pain due to lateral subluxation of the patella
Knee may give way
Patellar tendonitis
More common in athletic teenage boys
Chronic anterior knee pain that worsens after running
Tender below the patella on examination
mechanism of action: cholchicine
Inhibits microtubule polymerization by binding to tubulin, interfering with mitosis. Also inhibits neutrophil motility and activity
genetic cause of marfans
a defect in the FBN1 gene on chromosome 15 that codes for the protein fibrillin-1
hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) deficiency
Lesch-Nyhan syndrome
Lesch-Nyhan syndrome
x-linked recessive therefore only seen in boys
features: gout, renal failure, neurological deficits, learning difficulties, self-mutilation
Giant cell tumours of the bone - radiological features
double/soap bubble’ x-ray appearance around epiphysis of femur
tumour of multinucleated giant cells within a fibrous stroma
peak incidence: 20-40 years
occurs most frequently in the epiphyses of long bones
Langerhans cell histocytosis
child, bone pain in skull/proximal femur, cutaneous nodules, recurrent otitis media/mastoiditis
osteoma
benign ‘overgrowth’ of bone, most typically occuring on the skull
associated with Gardner’s syndrome (a variant of familial adenomatous polyposis, FAP)
osteochondroma
most common benign bone tumour
more in males, usually diagnosed in patients aged < 20 years
cartilage-capped bony projection on the external surface of a bone
Osteosarcoma
most common primary malignant bone tumour
seen mainly in children and adolescents
occurs most frequently in the metaphyseal region of long bones prior to epiphyseal closure, with 40% occuring in the femur, 20% in the tibia, and 10% in the humerus
x-ray shows Codman triangle (from periosteal elevation) and ‘sunburst’ pattern
mutation of the Rb gene significantly increases risk of osteosarcoma (hence association with retinoblastoma)
other predisposing factors include Paget’s disease of the bone and radiotherapy
Ewing’s sarcoma
small round blue cell tumour
seen mainly in children and adolescents
occurs most frequently in the pelvis and long bones. Tends to cause severe pain
associated with t(11;22) translocation which results in an EWS-FLI1 gene product
x-ray shows ‘onion skin’ appearance
chondrosarcoma
malignant tumour of cartilage
most commonly affects the axial skeleton
more common in middle-age
syndesmophytes
due to ossification of outer fibers of annulus fibrosus in ankylosing spondylitis
Familial Mediterranean Fever Diagnosis
Tel-Hashomer diagnostic criteria
recurrent episodes of serositis (peritonitis, synovitis, pericarditis) in association with fever and prompt response to colchicine.
Features of Familial Mediterranean Fever
pyrexia abdominal pain (due to peritonitis) pleurisy pericarditis arthritis erysipeloid rash on lower limbs
Methotrexate interactions
Trimethoprim and co-trimoxazole - increase risk of bone marrow suppression
High dose aspirin - increases the risk of methotrexate toxicity
Paget’s disease
Raised ALP Normal serum calcium Increased uncontrolled bone turn over Lytic lesions and thickened skull volt Advanced - can cause hearing loss
Markers of bone turnover in Pagets disease
procollagen type I N-terminal propeptide (PINP), serum C-telopeptide (CTx), urinary N-telopeptide (NTx), and urinary hydroxyproline
Features of drug induced lupus
arthralgia
myalgia
skin (e.g. malar rash) and pulmonary involvement (e.g. pleurisy) are common
ANA positive in 100%, dsDNA negative
anti-histone antibodies are found in 80-90%
anti-Ro, anti-Smith positive in around 5%
SLE in pregnancy
risk of maternal autoantibodies crossing the placenta
leads to a condition termed neonatal lupus erythematosus
neonatal complications include congenital heart block
strongly associated with anti-Ro (SSA) antibodies- causes peadiatric heart block
DMARD in pregnancy
Azathioprine
