Systemic Sclerosis (SSc)

Learning Objectives
Review the manifestations of Systemic Sclerosis (SSc)
Discuss management options
Approach to myositis in SSc

1. Manifestations of SSc include Skin, Vascular, Cardiac,Renal, Joint, Muscle and GI abnormalities
The hallmark of SSc is skin thickening and fibrosis with non-mendelian inheritance and heterogeneous presentation. Esp high incidence in Native Americans (Choctaw) and has rapid progression and poor prognosis in African Americans
a. Limited Cutaneous SSc involves skin distal to the elbows and knees but may also include face, neck
Pulmonary HTN is more likely in this group and may occur WITHOUT other pulmonary manifestations
hypothyroidism and primary biliary cirrhosis are seen as well
CREST is a subset of limited SS and includes calcinosis, raynaud's, esophageal dysmotility, telangiectasias,associated with +Anticentromere Antibody

b. Diffuse Cutaneous involves skin proximal to knees and elbows and trunk, face, neck
Pulmonary manifestations are common including ILD as are renal manifestations
Progresses more rapidly, worse prognosis
associated with +AntiScl 70 Antibody
For more, see Harrison's Ch 316

2. Management is symptomatic:
A. Cutaneous:
most common manifestation; cyclophosphamide, mycophenolate are used but frequently improve symptoms. Penicillamine helps with fibrosis in some
B. Vascular:
Raynaud's is most common->CCB is standard of care> alpha blockers and topical nitrates
C. MSK
Arthritis: usually inflammatory and treated like RA->steroids, mtx, etc
Myopathy: from collagen deposition,polymyositis, overlap syndrome. If true myositis, may treat with steroids (cautiously given risk of renal crisis)
Carpal Tunnel, tendon friction rubs
D. GI:
dysphagia- small frequent meals
Gerd- ppi, antacids, screening EGD (hi risk of barrett's)
pseudoileus- bowel rest
gastric and colonic dsymotility- prokinetics
bacterial overgrowth-abx ie) neomycin
GAVE-phototherapy
E. CV:myocardial and pericardial fibrosis-> arrhythmia, conduction abnormalities
F. Pulm: fibrosis-> cyclophosphamide
PAH: bosentan, etc
G. Neoplasm: lung, skin, hematologic malignancy are more common in SSc
Harrison's Ch 316, MKSAP 15: Rheumatology

3. Approach to Myositis in SS
Differential for myositis: unrelated/ideopathic, overlap syndrome, or mixed connective tissue disease( MCTD).
Limited SSc coexisting with features of SLE, polymyositis, and RA may be seen in MCTD, which is associated with high titers of autoantibodies to U1-RNP. Both Dermatomyositis (DM) and Polymyositis (PM) may bee seen with MCTD

Bohan and Peter Criteria for Inflammatory Myositis is an older tool, but underscores the important diagnostic modalities
**When present, these findings are highly suggestive of DM, PM
Labs: CK, AST, ALT, aldolase, LDH
PE: Symmetric Weakness, Rash
EMG: myopathic changes
Muscle biopsy: characteristics of DM, PM without other etiologies identified

(Ellen Eaton MD, 9/17/10)