systemic lupus erythematosus Flashcards
diagnosis of SLE
at least 4/11 diagnostic criteria
skin:
1. malar rash/ butterfly rash after sun exposure
2. discoid rash - plaque like and can scar
3. general photosensitivity of the skin
mucosa:
4. ulcers of mouth and nose
serosa:
5. serositis: pleuritis around lungs or chest cavity or pericarditis, endocarditis or myocarditis
joints:
6. arthritis of two or more joints
kidneys:
7. renal disorders: abnormal urine protein, diffuse proliferative GN
brain:
8. neurological disorders causing seizures or psychosis
blood:
9. haematological disorders: anaemia, thrombocytopaenia, lauekopaenia
antibodies:
10. Antinuclear antibody: sensitive but not specific to SLE
11. other antibodies: anti-smith, anti-dsDNA, anti-phospholipid
affects of SLE on the skin
skin:
1. malar rash/ butterfly rash after sun exposure
2. discoid rash - plaque like and can scar
3. general photosensitivity of the skin
affects of SLE on the mucosa
- ulcers of mouth and nose
affects of SLE on the serosa
- serositis: pleuritis around lungs or chest cavity or pericarditis, endocarditis or myocarditis
epidemiology
women of reproductive age
highest in african descent
aetiology of SLE
genetic predisposition
hormonal factors: high oestrogen states e.g due to oral contraceptive use, postmenoupausal hormone therapy, endometriosis
environmental factors eg. cigarette smoking and silica exposure
uV light and EBV infection can trigger flares
drugs can cause drug induced lupus erythematosus
clinical features
can affect any organ
constitutional: fatigue, fever, weight loss
joints: arthritis and arthralgia, distal symmetrical polyarthritis (SLE does not lead to deformity unlike RA)
skin:
- malar rash: flat or raised erythema overr both malar eminences
- raynaud phenomenon
- photosensitivity
- discoid rash
- oral ulcers
- non scarring alopaecia
laboritory studies
antinuclear antibodies
antigen specific ANAs - request if ANAs are positive
Anti-dsDNA
- autoantibodies against double stranded DNA
- highly specific for SLE
- levels correlate with disease activity
Anti-Sm
- autoantibodies against smith antigens
- only positive in 30% but highly specific for SLE
anti phospholipid antibodies - screen all patients for anti phospholipid syndrome
lab markers of disease activity or active organ damage in SLE
decreased compliment levels
inflammatory markers: high ESR and CRP.
FBC may show leukopaenia, thrombocytopaenia, or anaemia of chronic disease
metabolic panel may show high BUN or creatinine or electrolyte abnormalities
urinalysis may show protienuria, haematuria or urinary casts
ESR
Erythrocyte sedimentation rate
Abbreviation: ESR
A test that measures the distance erythrocytes fall after one hour in a vertical tube of anticoagulated blood. Can be elevated in many conditions such as infection, inflammation, and malignancy.
antibody specificity in SLE
ANAs are highly sensitive but not specific
anti-dsDNA and anti-sm are most specific for SLE
imaging studies
x-ray joints: perform in patients with articular symptoms
x-ray or CT chest: perform in patients with pulmonary involvement
echocardiography: in patients with suspected pericardial effusion or Libman-sacks endocarditis
general principles of treatment
usually require lifelong immunosuppressants
NSAIDs can providesymptomatic relief
smoking cessation, aerobic excercise
avoidance of UV light
pharmacology
all patients: hydroxychloroquinine iss the cornerstone of therapy regardless of disease activity
consider oral glucocorticoids for mild to moderate disease
for severe disease: induction therapy with high dose IV glucocorticoids and other immunosuppressive agents
monitoring of medication induced side effects
immunisations
monitor for side effects of glucocorticoid therapy
hydroxychloroquinine: request opthalmologic screening at baseline, after 5 years, and every year thereafter
