Rheumatology Flashcards
What is polymyositis
inflammation of the muscles
What is dermatomyositis
connective tissue disorder where there is chronic inflammation in the skin and muscles
Key diagnostic factor for dermatomyositis
creatine kinase
Presentation of dermatomyositis
- Muscle pain, fatigue and muscle weakness
- Occurs bilaterally and typically affects proximal muscles
- Mostly affects the shoulder and pelvic girdle
- Develops over weeks
Dermatomyositis skin features
- Gottron lesions (scaly erythematous patches) on the knuckles, elbows and knees
- Photosensitive malar rash on the back, shoulders and neck
- Purple rash on eyelids and face
- Periorbital oedema (swelling around the eyes)
- Subcutaneous calcinosis (calcium deposits in the subcut tissue)
Autoantibody associated with polymyositis
Anti-Jo-1 antibodies
Autoantibodies associated with dermatomyositis
anti-m2 antibody
ANA antibody
How to diagnose dermatomyositis
clinical presentation
elevated CK
autoantibodies
EMG
Muscle biopsy for definitive diagnosis
Management of dermatomyositis
Guided by rheumatologist
corticosteroid - first line
Other: azathioprine, IV immunoglobulins, infliximab
Pathophysiology of SLE
characterised by ANA
Presentation of SLE
vague and non specific
Photosensitive malar rash - butterfly shaped rash over nose and cheekbones that gets worse with sunlight exposure
Investigations for SLE
autoantibodies
FBC - normocytic anaemia of chronic disease
C3 and C4 levels - decreased in active disease
CRP and ESR
Immunoglobulins - raised due to activation of B cells with inflammation
Urinalysis and protein:creatine ratio for proteinuria in lupus nephritis
renal biopsy to investigation lupus nephritis
Autoantibodies for SLE
- ANA (anti nuclear antibodies)
- Initial investigation for someone presenting with SLE
- Can be positive in healthy patients or patients with other autoimmune conditions
- Need to be taken in context of presenting symptoms
- Anti-dsDNA (anti double stranded DNA)
- More specific to SLE
- Levels vary with disease activity so can be used for disease monitoring and response to treatment
How to diagnose SLE
SLICC criteria
ACR criteria
First line treatment for SLE
NSAIDs
Steroids - prednisolone
Hydroxyhlorquine (mild SLE)
What is rheumatoid arthritis
Autoimmune condition that causes chronic inflammation of the synovial lining of the joints, tendon sheaths and bursa. It is an inflammatory arthritis and symmetrical polyarthritis
Genetic associations of RA
- HLA DR4 - often present in RF positive patients
- HLA DR1 - occasionally positive in RA patients
Specific antibody for RA
Anti-ccp
What is palindromic rheumatism
- involves self-limiting short episodes of inflammatory arthritis with joint pain, stiffness and swelling typically only affecting a few joints
- Episodes only last 1-2 days and then completely resolve
- Having positive antibodies indicates that it will probably progress to RA
Are DIP joints affected in RA
no
RA signs in the hands
- Z shaped deformity to the thumb
- Swan neck deformity (hyperextended PIP with flexed DIP)
- Boutonnieres deformity (hyperextended DIP with flexed PIP)
- Ulnar deviation of the fingers at the knuckle (MCP joints
Investigations for RA
- Z shaped deformity to the thumb
- Swan neck deformity (hyperextended PIP with flexed DIP)
- Boutonnieres deformity (hyperextended DIP with flexed PIP)
- Ulnar deviation of the fingers at the knuckle (MCP joints
Xray changes in RA
- Joint destruction and deformity
- Soft tissue swelling
- Periarticular osteopenia
- Boney erosions
When do you refer for RA
- Recommended for any adult with persistent synovitis even if negative RF, anti-ccp, and inflammatory markers
- Should be urgent referral if involves small joints of hands or feet , multiple joints or symptoms have been present for over 3 months
