MSK Flashcards
mechanism of action of methotrexate
dihydrofolate reductase inhibitor leading to reduced DNA synthesis
side effects of methotrexate
- agranulocytosis
- stomatitis
- bone marrow suppression -> pancytopenia
- liver toxicity
- alopecia
monitoring with methotrexate
- FBC
- LFT
- renal function before starting
- give with folic acid
mechanism of action of rituximab
targets CD20 on B cells
mechanism of action of anakinra
interleukin 1 receptor antagonist
mechanism of action of azathioprine
inhibits synthesis of purines
side effects of azathioprine
- pancreatitis
- anaemia
- GI upset
- leukopenia
side effect of ciclosporin
gingival hypertrophy
features of systemic JIA
2 weeks of fever and salmon pink rash.
symmetrical joint pain
+/- hepatosplenomegaly, pericarditis, peritonitis, pleuritis
features of oligoarticular arthritis
most common
<4 joints involved (usually lower joints)
+ uveitis (presents before arthritis, ANA +ve)
features of polyarticular arthritis
> 5 joints involved (usually smaller joints)
often girls
rheumatoid factor +ve (= poorer prognosis)
features of enthesitis arthritis
arthritis plus…
- sacro-iliac / lumbrosacral pain
- heel pain and lower limb pain
- acute anterior uveitis
HLA B27 +ve, boys
features of juvenile psoriatic arthritis
- affects small and large joints asymetrically
- dactylitis
- nail pitting
- oncholytis
investigations for JIA
clinical diagnosis …
- raised ESR
- ANA - if +ve, important in predicting uveitis and blindness (need regular slit lamp examinations)
- rheumatoid factor - +ve in polyarticular.
- USS joint
management of juvenile arthritis
- physiotherapy
- pain relief - NSAIDS (naproxen)
- steroids - intraarticular for oligoarticular
- methotrexate
- DMARDS
side effects of intra-articular arthritis
- peri articular calcifciation
- atrophy of site
- hypopigmentation
- crystal synovitis
- avascular necrosis of femoral head
features of SLE/ diagnsosis
need >4/11 features of….
S - serositis e.g. pericarditis, myocarditis
O- oral ulcers
A - arthritis
P - photosensitivity
B - Blood disorder e.g. haemolytic anaemia, thrombocytopenia, leukopenia
R - renal e.g. lupus nephritis
A- ANA +ve
I - immunological e.g dsDNA +ve
N - neurological e.g. psychosis, seizures
M- malar rash - butterfly rash across face
D - discoid rash - sun exposed areas, scaling
management of SLE
- sun exposure, exercise
- NSAIDs
- steroids - pred gives rapid symptomatic relief
- immunosuppressive agents e.g. azathioprine, methotrexate
features of behcets disease
HLA B5
- uveitis
- erythema nodosum
- oral and genital ulcers
- thrombophlebitis
cause of reactive arthritis
HLA- B27
- diarrhoea e.g. campylobacter, salmonella
- gonorrhoea/ chlamydia
features of reactive arthritis
- arthritis
- conjunctivitis/ uveitis
- urethritis
risk factors for SUFE
- boys
- obesity
- adolescents
- previous radiation of hip
- endocrine disorders e.g. hypothyroid, GH deficiency, short stature
presentation of SUFE
- pain in hip/ groin/ medial thigh on walking
- limp
- limited hip rotation
complications of SUFE
- avascular necrosis of femoral head
- osteoarthritis
- osteonecrosis
investigations for SUFE
anteroposterior and frog leg lateral x rays…
- femoral head displacement
- widened epiphyseal line
- globular swelling of joint capsule
management of SUFE
- rest
- analgesia
- surgery - screw fixation across growth plate
risk factors for perthes disease
- boys
- 4 - 11 y/o
presentation of perthes disease
- pain and limitation on internal rotation and abduction of hip
- afebrile
x ray of perthes disease
radiolucency of femoral head (= avascular necrosis_
management of perthes disease
abduction bracing +/- osteostomy (containment)
put in a Petrie cast
presentation of osgood schlatter
- boys
- playing sport
- pain in knee
causes of osteomyelitis
NEONATES (Affects femur/ humerus)
- GBS
- s.aureus
- e.coli
INFANT (affects long bone metaphysis)
- s. aureus **
- k. kingae (chronic)
- salmonella (sickle cell)
risk factors for osteomeylitis
- trauma
- sickle cell disease
- previous surgery
- diabetes
- immunocompromised
- blood stream infections
presentation of osteomyelitis
- fever unwell
- localised bone pain/ swelling
what is brodies abscess
- localised deep abscess in bone
- causes deep boring pain
investigations for osteomyelitis
- bloods - raised CRP, raised ESR, raised WCC
- blood cultures
- x ray - radiolucent metaphyseal lesions, periosteal elevation
- MRI - detects early changes
management of osteomyelitis
- IV antibiotics for 4-6 weeks
- analgesia
presentation of septic arthritis
- red hot swollen painful joint
- fever
- unable to weight bear
management of septic arthritis
- USS joint aspiration
- FBC, CRP, cultures
- IV antibiotics for 4-6 weeks
presentation of hypermobility
pain that worsens during course of the day and afetr exercise
back pain
poor posture
score for hypermobility and management
BEIGHTON SCORE
> 4/9 = hypermobile
need physiotherapy
cause of ehlers danlos syndrome
autosomal dominant
mutation in COL5A12 gene
defective collagen V
presentation of ehlers danlos syndrome
- hyperextensilibity of skin
- hypermobile
- hypotonia
- developmental delay
- poor wound healing
- blue sclera
- aortic regurg + aortic dissection
cause of ankylosing spondylitis
HLA B27
autoimmune
common in adolescent boys
presentation of anylosing spondylitis
- back pain - and radiates to back of legs
- stiffness - worse in morning, relieved by exercise
- aortic regurg
- pulmonary fibrosis
- iBD
- nephrotic syndrome
x ray signs of ankylosing spondylitis
- 1st sign = loss of costal margins, blurring of vertebral junction
- widening of joint space
- anterior squaring of vertebra
- late sign = marginal sclerosis, narrowing and fusion
cause of rickets
- nutritional deficiency - low calcium and low vit D intake, risk if vegetarian/ vegan/ prolonged breastfeeding
- malabsorption e.g. coeliac, cystic fibrosis
- lack of sunlight
- liver disease
- renal tubular loss e.g x linked dominant hypophosphataemia. fanconi, cystnosis
presentation of rickets
- tender swollen joints
- genu varum + valgum
- delayed walking
- skull bossing
- delayed formation of teeth , enamel hypoplasia
x ray in rickets
- cupping, splaying and fraying of metaphysis
- costochondral swelling
- loosers zone
bloods of vit D deficient rickets
- low vit D
- low or normal calcium
- high ALP
- high PTH
- low phosphate
bloods of hypophosphataemic rickets
- normal vit D
- normal calcium
- high ALP
- low phosphate
- normal/ high/ low pTH
complications of rickets
- cardiomyopathy
- hypocalcaemic seizures
- delayed gross motor delay
- faltering growth
features of type 1 osteogeneis imperfecta
autosomal dominant
blue scleria
easy bruising
fractures
hearing loss
cause of hSP
systemic vasculitis - IgA mediated of small blood vessels
presentation of HSP
- skin rash - blanching maculopapular rash -> petechie, purpura
- abdominal pain, diarrhoea
- arthritis - with swelling/ oedema
- nephritis - proteinuria/ haematuria / AKI
management of HSP
- rule out other conditions e.g. FBC, U&E, CRP clotting
- may need renal biopsy if kideny issues - IgA deposits
- BP and urinanalysis at day 7, 14 and then 1, 3, 6 and 12 months
different rashes in dermatomyositis
- gottrons papules
- shawl rash - sun exposed areas
- heliotrope rash - blue/ purple discolouration of eyelids
- mechanic hands
features of dermatomyositis
- 1st sign = rashes
- muscle weakness - proximal muscles (shoulders/ neck)
- dysphagia, dysphonoa
- muscle atrophy and tenderness
- restrictive pulmonary disease
- fatigue
diagnosis of dermatomyositis
diagnosis = muscle biopsy + MRI lower limbs
- raised cK
- raised ALT (1st to rise), raised LDH, raised aldolase
- ANA +ve 80%
- myotis specific antibodies e.g. anti Jo-1, anti Mi2
management of dermatomyositis
- corticosteroids
- methotrexate/ hydroxychloroquine
criteria for kawasakis disease
C - conjunctivitis - bilateral, non purulent
R - rash - polymorphous rash
A - adenopathy - cervical lympahdenopathy, non tender, unilateral or b/l
S - strawberry tongue, dry lips
H - hands - desquamation of hands and feeds
+BURN for >5 days
features of polyarteritis nodosa
- livedo reticularis
- hypertension
- weight loss
- fever
- aneurysm nodules
- leg/ arm weakness, fatigue
what is polyarteritis nodosa
autoimmune dosease
small + medium size vessel vasculitis -> causes transmural fibrinoid necrosis
