Page 370 - Medicine and Surgery

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366 Chapter 8: Musculoskeletal system

Skin: (70–80%): Neuropsychiatric (59–75%):
Butterfly : malar rash ~50% patients Seizures, hemiplegia, ataxia, various
at some stage. Photosensitivity more neuropathies. Cognitive dysfunction.
during active disease. Mouth ulcers, Depression and behavioural problems.
purpura, urticaria, thrombophlebitis.
Vasculitis with fingertip infarcts, and
Eyes:
vasculitic lesions on elbows. Mild-
Vasculitis of retinal blood vessels
moderate Raynaud's phenomenon,
causes infarcts (hard exudates). Other
alopecia, purpura & urticaria are seen.
features are conjunctivitis, episcleritis
¨
and Sicca (Sjogren's) syndrome.
Lung (48%):
Lung function tests show restrictive
pattern and diffusion defects due to Kidney (50%):
fibrosis, pleurisy effusions and Commonest feature is proteinuria
pneumonitis (shrinking lung syndrome). i. Glomerulonephritis (focal
proliferative, proteinuria)
ii. Diffuse proliferative: crescents in
Heart (25%): most severe cases (proteinuria,
Pericarditis with small effusions casts, renal failure & hypertension)
(tamponade is rare), mild myocarditis iii. Membranous (proteinuria,
and arrhythmias. Aortic and mitral nephrotic syndrome)
valve lesions occur rarely.
iv. Mesangial (usually benign and
may remain subclinical)
Musculo-articular (95%):
Small joint symmetrical pain and
myalgia are common but joints appear
normal on examination.
Erosive arthriris and true myositis do Haematology:
occur but are rare. i. Splenomegaly in 25%
Jaccoud's arthropathy (a major joint ii. Lymphadenopathy in 50%
deforming arthritis resembling RA). iii. Anaemia of chronic disease
iv. Haemolytic anaemia, pancytopaenia

Figure 8.3 Systemic manifestations of systemic lupus erythematosus.

Immune complex deposition in skin at the dermal– cardiolipin is a component of the antigenic mixture
epidermal junction, kidney and blood vessels. used in these assays). The fluorescent Treponema pal-
lidum antibody test is negative.
Investigations ESR is raised in active disease, with normal CRP levels.
ANAs seen in 95–99% of SLE. Anti-double stranded
Immunoglobulins usually polyclonal increase in gam-
DNA antibodies are relatively specific but only 50% maglobulins.
sensitive. Other autoantibodies seen include anti- Haematological abnormalities:
RNP, anti-smooth muscle, anti-Ro (SSa) and anti-La 1 Normochromic, normocytic anaemia in 75%.
(SSb). Rheumatoid factor is seen in 50%. 2 Direct antiglobulin test positive haemolytic anae-
Complement is low during active disease suggesting
mia in 10–20%.
complement activation and consumption by immune 3 Leucopenia and mild thrombocytopaenia.
complexes. 4 Antibodies to clotting factors especially lupus anti-
False positive tests for syphilis are found in approxi-
coagulant directed against prothrombin activator
mately10%ofpatients(positiveWRorVDRLbecause (see below).