The authors present an overview of scleroderma classification as a whole, classification criteria of systemic sclerosis (SSc) and its subclassification into two subsets: limited and diffuse. Variability of SSc clinical course, early organ dysfunction of diffuse subset, difficulty of the disease activity assessment need standardized tools for monitoring the disease severity (the disease status), which are necessary for predicting prognosis of an individual patient and for evaluation of clinical trials. The disease severity at a given time represents combination of tissue damage, i.e. irreversible organ dysfunction, and disease activity, i.e. potentially reversible organ dysfunction. The preliminary disease severity criteria evaluating nine organ systems in 4-grade-scale recommended for use in clinical trials by European Scleroderma Study Group, ESSG, are reviewed. Also the preliminary clinical SSc activity criteria identified in multicenter clinical study designed by the same group, which are validated in another ongoing study organized by recently founded European group EUSTAR, i.e. EUlar (European League Against Rheumatism) Scleroderma Trials And Research, are presented. The list of “core set“ and special potential serological markers of the disease activity derived from the pathogenesis of SSc, which were selected for clinical trials by ESSG, are included.

        Key words: scleroderma - systemic sclerosis - classification - severity - activity