Connective
Tissue Diseases
(Read and study the relevant articles in the course manual)
Characteristics
of connective tissue diseases:
*
group of chronic inflammatory diseases
* predominantly affect women
* involve many different organs
* wide spectrum of clinical manifestations
* multifactorial aetiology - immunological, genetic and environmental
(possibly viral)
* Klemperer (1942) - coined the term 'collagen diseases'
Diseases included in this category:
- Rheumatoid arthritis
- Systemic lupus erythematosus (SLE is used as the eg in this course
of a CTD)
- Systemic Sclerosis
- Poly- and dermatomyositis
- Polyarteritis nodosa
- Sjogren’s Syndrome
- mixed
Common
Features:
- Constitutional features (sex and genetic predisposition)
- Overlapping clinical features (vide infra)
- Overlapping pathological features (eg blood vessel changes)
- Immunological abnormalities (vide infra)
Systemic
Lupus Erythematosis:
- one of the more common connective tissue diseases
- large variance in clinical presentation
- wide spread organ involvement
- involvement of multiple organ systems is mediated by immunologic
abnormalities eg auto-antibodies to DNA
Epidemiology
of SLE:
- increasing frequency (? more sensitive serological tests)
- onset most common in females of childbearing years (?oestrogen
levels at highest)
- 70 new cases per year per 1 000 000 population
- In NZ: prevalance of 1:6780, but in Polynesians - 1:1975
- In New York blacks 1:1000
Aetiology
of SLE:
- elusive
- environmental and hormonal factors play a role
- ? environmental factor in a particular genetic milleu trigger
immunological abnormalities - these circulating immune complexes
mediate tissue injury
- Genetic - females; racial differences; 5% of first degree relatives;
HLA-DR2 & HLA-DR3
- Environmental - exacerbated by sunlight; some viral evidence;
precipitated by drugs
Clinical
Features of SLE:
- wide variety of presentations
- early diagnosis is difficult
Common
clinical presentations - fatigue, malaise, fever, weight loss, marked
musculoskeletal symptoms, mild peripheral synovitis, rash
Uncommom
- fever of unknown origin, pleurisy, renal manifestations, pericarditis,
purpura, leukopenia.
Serological
findings in SLE:
- 80% hypergammaglobulinaemia
- 95% ANA
- 40% R factor
- 30% Positive Coombs test
- 20% False positive VDRL
Diagnosis
depends on organ involvement and the demonstration of immunologic
abnormalities
Clinical
Manifestation During Course of SLE
- Musculoarticular 95%
- Haemotologic 85%
- Cutaneous disease 80%
- Fever without cause 80%
- Easy fatigability 80%
- Neuropsychiatric disease 60%
- Renal disease 55%
- Cardiac disease 50%
- GI complaints 45%
- Conjunctivitis 10%
- Sicca syndrome 10%
- Thrombophlebitis 9%
- Retinal problems 5%
Musculoskeletal involvement in SLE
- general myositis/myalgia is common
- mild painful symmetric polyarthritis is first manifestation in
75-90% - more common in small hands joints, knee, shoulder
- 40% develop a deforming non-erosive arthropathy - deformities
are passively correctable
in foot, pattern of involvement is similar to RA - only on rare
occasions is the inflammation pronounced to cause erosions
- spontaneous weakening and rupture of tendons (?steroids)
- infarcts or osteonecrosis
Mizutani
& Quismorio (1984):
* 30 SLE patients;
14
with hand deformities --- 10 had painful tender feet; 13 had HAV;
5 subluxed MPJ’s; 6 forefoot spread; 3 flexible flatfoot;
1 rigid flatfoot
16 without hand deformities --- 6 had painful tender feet; 2 had
HAV; 3 had flexible flat foot
3 had forefoot spread
Cutaneous involvement in SLE:
- 30%+ have the characteristic butterfly rash on the face
- 30% photosensitive
- 28% have chronic discoid lesions
- 18% have raynauds
- 25% have nail changes resembling onychomycosis
- subungual hyperkeratosis can occur in some forms of SLE
Kidwa &
Roth (1978)
- 22 yr old black female
- painful eruptions on the sole of the foot preceded the diagnosis
of SLE by 6 months
- described as hyperkeratosis, raised erythematous, depigmented
and a yellow-white intervening layer of a ‘cheese’ like
texture
- eventually spread to dorsum, legs, arms and neck
Radiographic
Changes in SLE:
-
non-specific
In
the foot:
- subluxation 37%
- diffuse osteopenia 29%
- cystic changes 20%
- alignment abnormalities 14%
- joint space narrowing MPJ 14%
- TN 10%
- CC 8%
- MTJ 8%
- IPJ 8%
- STJ 4%
- erosions 5th MPJ 8%
- 1st MPJ 6%
- soft tissue calcification 10%
- periositis 8%
-
severe dislocation with no erosions
-
metatarsal infarction from high doses of corticosteroids
-
focal bone sclerosis and resorption
Variants
of SLE:
- Drug induced lupus (eg anticonvulsants)
- Mixed connective tissue disease
- Discoid lupus erythematous (DLE) - benign cutaneous form
Variants
of DLE:
- DLE confined to head and neck
- Disseminated DLE
- Chilblain DLE (vide infra)
- LE erythema multifome (lesions resemble EM)
- Subacute DLE
- Acute DLE
Chilblain
LE or Lupus pernio:
- up to 20% of those with DLE have chilblains on feet as the presenting
feature
- chilblains usually persist when skin lesions remit
- have an increased risk of developing SLE
Management
of SLE:
- education; rest during acute phases; avoidance of sunlight
(if photosensitive)
- NSAID’s
- drugs to suppress exacerbations - (antimalarials)
- corticosteroids and immunosupressives
Prognosis:
10 yr survival rate of 90%
Involvement
of the Foot in SLE:
- Symmetric polyarthritis
- Non-erosive deforming arthropathy
- Nail dystrophies
- Osteonecrosis
- Nailfold capillary abnormalities
- Chilblains/pernio
- Raynaud’s phenomen
- Hyperkeratotic lesions
- Vasculitis
- General tenderness
- Peripheral vascular disease
What
can the patient with SLE expect from a Podiatrist:
- aseptic debridement of dystrophic nails and hyperkeratotic
lesions
- routine care of feet
- prevention of deformity
- footwear/footcare advice
- an awareness of the rarer initial presentations of SLE in the
foot
- an empathy with the patient - an understanding with the patient
of the nature of the disease
- appropriate referrals and liaison
Online
links:
Full
text article on Systemic lupus erythematosus from Postgraduate Medicine
ePodiatry's
links to online articels on connective
tissue diseases
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