20% of dSSc
kinetochores, CENP-A, B,C, E
60-80% of lSSc; 15% of SSc
characteristic skin changes
15% of overlap syndromes
< 10% of overlap syndromes
10% of overlap syndromes
antinuclear antibodies (ANA) (Bunn et al. 1998), thus making the diagnosis of SSc in a patient without ANA quite unlikely. Although there is no antibody which can be related to disease activity like the presence of anti-ds DNA antibodies in systemic lupus erythematosus, patient classification according to serologic subsets can be meaningful. Nearly 85% of patients can be associated to one of seven SSc related antibodies (Table 1) and each of these antibodies describes a subset which to a different degree has characteristic clinical manifestations (Fig. 2, 3).
At clinical presentation, sclerodactily is present in about 95% of patients and Raynaud's syndrome is present in about 90%. If none of these features (including ANA) is present, the patient is likely to have a disorder other than SSc.
Differential diagnosis includes in particular the generalized form of localized scleroderma, eosinophilic fasciitis, scleromyxoedema, scleroderma adultorum Buschke, amyloidosis, porphyria cutanea tarda and acrodermatitis chronica
Fig. 3. Clinical phenotype of progressive systemic sclerosis and overlap syndromes. A. Diffuse systemic scleroderma: diffuse sclerosis with hyperpigmentation of the trunk. B. Sclerodactyly with contractures and atrophy of the fingers. C. Cutaneous calcinosis. D. PM-Scl overlap syndrome: mechanic hands with hyperkeratosis of the fingers
Fig. 3. Clinical phenotype of progressive systemic sclerosis and overlap syndromes. A. Diffuse systemic scleroderma: diffuse sclerosis with hyperpigmentation of the trunk. B. Sclerodactyly with contractures and atrophy of the fingers. C. Cutaneous calcinosis. D. PM-Scl overlap syndrome: mechanic hands with hyperkeratosis of the fingers atrophicans in the inflammatory phase (Table 2) and rarely sclerodermiform genodermatoses. Furthermore, one has to be aware of the vast differential diagnoses of Raynaud's phenomenon in the patients presenting in the initial phase of the disease.
Table 2. Scleroderma-Like Disorders
I. Sclerotic disorders Scleroderma adultorum Buschke
Scleroderma diabeticorum Scleroderma amyloidosum Scleromyxedema
Environmentally related scleroderma-like syndromes Graft versus host disease Porphyria cutanea tarda Acrodermatitis chronica atrophicans
II. Sclerodermiform genodermatoses Werner Syndrome
Association of SSc with other autoimmune diseases is relatively common including primary biliary cirrhosis, Sjogren-syndrome (including the detection of anti-Ro/La antibodies) and the subset of overlap syndromes, dermatomyo-sitis and polymyositis.
Was this article helpful?