Lupus & Scleroderma Similarities and Differences
by Daniel J. Wallace M.D., F.A.C.P., F.A.C.R.
Some patients may be told they have lupus by one doctor, only for another consultant to state they have a scleroderma related disorder. How could this be the case? What are the similarities and differences of these conditions?
Scleroderma and l
upus are both autoimmune diseases. Both are predominantly found in women and have genetic association, although this is much stronger in lupus. The age of greatest onset is 15 to 45 for lupus and 20 to 60 for scleroderma.
In scleroderma, four pathologic processes are present: inflammation, cross-linking of collagen leading to tight skin, fibrosis or scarring of tissues, and vascular endothelial changes leading to lack of oxygen to the hands and feet. Lupus is primarily an inflammatory process.
Lupus and scleroderma can “cross-over” or have overlapping symptoms and signs. For example, Raynaud’s or esophageal dysfunction is found in 90% with scleroderma but 30% with lupus, swollen joints in half with lupus and 30% with scleroderma, and positive ANA in 98% with lupus and 80% with scleroderma. If anti-RNP is present on blood testing, a patient may have a “mixed connective tissue disease,” especially if puffy hands and Raynaud’s are present. Tight skin is not a feature of lupus and sun sensitivity is not found in scleroderma. Anti-DNA, anti SM, anti Ro (SSA), anti La (SSB), and low complement are blood tests found in lupus whereas scleroder
ma patients may have an anti-Scl 70 anti centromere antibody.
Nonsterodial anti-inflammatory drugs and hydroxychloroquine (Plaquenil) help both conditions. Most patients with pure schleroderma do not benefit from corticosteroids. Methotrexate, azathioprine, prednisone or cyclophosphamide help lupus and overlap syndromes, and perhaps scleroderma lung disease. Scleroderma may modestly benefit from d-penicillamine, relaxin, and minocycline, none of which help lupus.
The prognosis of lupus is: normal survival with non-organ threatenting disease, 50%, 20 year survival with heart, lung, kidney or liver involvement. The prognosis of scleroderma is: near normal with morphea or other forms of localized scleroderma, usually normal with limited (CREST) syndrome, and 50% ten year survival with progressive slcerosis, where organs are usually involved.
The Lupus Foundation and Scleroderma Foundation have resources to provide patients with additional information, physician referrals, and information regarding support groups and research opportunities. Twice in the last 10 years, they have held fund raising events together.