RESUMEN
Systemic sclerosis (SSc) is a connective tissue disease of unknown origin, which is characterized by fibrosis of the skin and internal organs, and endothelial and immunologic dysfunction. The presence of a wide range of symptoms renders disease classification difficult. Although recent studies have contributed to our understanding of this debilitating illness, well-validated classification criteria are required for accurate comparison between registries and clinical trials, to assess response to treatment, morbidity and prognosis. Given the emphasis placed upon early and aggressive treatment, the 1980 American College of Rheumatology (ACR) classification criteria are of limited utility with respect to early diagnosis of SSc and limited cutaneous SSc. Recently, the 2013 ACR/European League Against Rheumatism classification criteria for SSc were published for research and clinical practice purposes. These criteria include skin thickening, fingertip lesions, telangiectasia, abnormal nailfold capillaries, Raynaud's phenomenon, SSc-specific autoantibodies and pulmonary complications pertaining to vasculopathy, autoimmunity and fibrosis. These updated criteria should allow a greater number of patients to receive an early diagnosis of SSc.