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Systemic sclerosis (SCc) is a rare, severe autoimmune disorder
characterized by sclerotic changes of the skin and internal organs.
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1. Limited SCc is characterized by fibrotic changes
of the fingers, hands, and face. Includes CREST (Calcinosis cutis,
Raynaud’s, Esophageal dysfunction, Sclerodactyly, Telangiectasia) syndrome.
2. Diffuse SCc: Fibrotic changes of the fingers, hands, arms,
trunk, face, and lower extremities.
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Synonyms Progressive systemic sclerosis,
systemic scleroderma.
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Age All ages. Peak: 30 to 50 years.
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Genetics A 15-fold increase in
first-degree relatives.
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The pathogenesis of SCc is unknown. The primary event might be
autoimmune endothelial cell injury in blood vessels. Early in the
course of the disease, target organ edema occurs followed by fibrosis;
the cutaneous capillaries are reduced in number and the remaining
vessels dilate and proliferate, becoming visible telangiectasias.
Fibrosis is also present because of overproduction of collagen by
fibroblasts.
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Raynaud’s phenomenon with pain/tingling of
the fingertips/toes is usually the first sign of SCc. Patients
with SCc have a characteristic tightening of the facial features
producing a pinched-nose, pursed-lip appearance (Fig. 17-11). Systemic
involvement leads to migratory polyarthritis, heartburn, dysphagia,
constipation, diarrhea, abdominal bloating, malabsorption, weight
loss, exertional dyspnea, and dry cough.
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Type Macules, edematous plaques,
ulcerations.
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Color Triphasic: pallor, cyanosis,
rubor. Hypo-hyperpigmentation.
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Fingers Sclerodactyly, flexion
contractures (Fig. 17-12), bony resorption, periungual telangiectasia,
cutaneous calcifications (Fig. 17-13).
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Face Masklike, thinning of lips,
small mouth, radial perioral furrowing, small sharp nose.
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Palpation Indurated, stiff, smooth,
hardened, bound down. Leathery crepitation over joints.
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Distribution Fingers, hands, upper
extremities, trunk, face, lower extremities.
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Hair Thinning/complete
loss of hair on distal extremities. Loss of sweat glands with anhidrosis.
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Nails Nails grow clawlike over
shortened distal phalanges..
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Other Mat-like telangiectasia on
face, neck, upper trunk, hands, lips, oral mucous membranes, gastrointestinal
(GI) tract.
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Mucous Membranes Sclerosis of sublingual
ligament, induration of gums, tongue.
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Lung Interstitial lung disease,
pulmonary fibrosis, pulmonary artery hypertension.
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Cardiac Congestive heart failure.
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Renal Hypertensive renal disease.
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Gastrointestinal Esophageal reflux,
dysphagia, constipation, diarrhea, malabsorption.
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Musculoskeletal Carpal tunnel syndrome.
Muscle weakness.
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Differential
Diagnosis
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Other sclerotic entities that need to be considered in the differential
diagnosis of SCc include scleredema, scleromyxedema, MCTD, eosinophilic
fasciitis, LE, DM, morphea, chronic graft-versus-host disease, lichen
sclerosis et atrophicus, polyvinyl chloride exposure, and adverse
drug reaction (pentazocine, bleomycin).
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Laboratory Examinations
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Dermatopathology A mild cellular
infiltrate around dermal blood vessels, eccrine coils, subcutaneous
tissue, effacement of the rete ridges; paucity of blood vessels,
thickening and hyalinization of vessel walls, narrowing of lumen;
atrophied dermal appendages; calcium deposits; and compact, homogenized collagen.
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Serology ANA-positive, nucleolar,
discrete speckled pattern. Diffuse SCc: anti-topoisomerase I (Scl
70), anti-RNA-polymerase I and III, anti-fibrillarin. Limited SCc:
anticentromere antibodies.
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The course for diffuse SCc is characterized by slow, relentless
progression of skin and/or visceral sclerosis; 80% of
patients die within 10 years after the onset of symptoms. With angiotensin-converting
enzyme inhibitors for the management of renal crisis, the leading
cause of death in SCc is cardiac and pulmonary dysfunction. Spontaneous
remissions do occur. CREST syndrome progresses more slowly and has
a more favorable prognosis.
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The treatment of SCc is primarily focused on internal organ disease.
For polyarthritis, salicylates and NSAIDs are helpful. For Raynaud’s
phenomenon, calcium channel blockers (nifedipine), angiotensin II
receptor blockers (losartan), intravenous prostaglandin E1 (alprostadil)
can improve circulation. For renal disease, angiotensin-converting
enzyme inhibitors have been life-saving. For GI involvement, small
frequent meals, head elevation in bed, antacids, and prokinetic agents
can help. For pulmonary disease, cyclophosphamide, mycophenolate
mofetil, azathioprine, chlorambucil, 5-fluorouracil, cyclosporine,
systemic steroids, prostacyclin analogues (epoprostenol, treprostinil),
and endothelin receptor antagonists (sildenafil, sitaxsentan) have
been used.
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Cutaneous SCc can be managed with avoidance of vasospastic agents
(cold, stress, fatigue, smoking), minimizing trauma. For cutaneous
ulcers, occlusive wet dressings, enzyme debriding agents (collagenase),
and topical growth factors (PDGF) can be helpful. For severe cases,
systemic therapeutic modalities, such as, minocycline, methotrexate,
corticosteroids, extracorporeal photophoresis, calcipotriol, D-penicillamine,
colchicine, and potassium P-aminobenzoate, psoralen ultraviolet
A, and UVA1 have been tried with varied results.