Are There Clinical Differences in Limited Systemic Sclerosis according to Extension of Skin Involvement?

Objectives. To examine the characteristics of our patients with limited systemic sclerosis (lSSc) for differences between Barnett Type 1 (sclerodactyly only) and Type 2 or intermediate (acrosclerosis-distal but may reach up to elbows and/or knees plus face) subsets. Methods. Records of patients between January 1, 2000, and December 31, 2011, with SSc or those with anti-Scl-70, anticentromere, or antinucleolar antibodies were reviewed. Only cases fulfilling ACR 1980 criteria were included and classified as diffuse or limited according to LeRoy’s criteria. Limited SSc was separated into sclerodactyly and acrosclerosis (Barnett’s Types 1 and 2). Results. 234 SSc patients (216 females) fulfilled criteria. Female/male ratio was 12？:？1; 24% had dSSc and 76% lSSC (64% Type 1 and 12% Type 2). Total follow-up was 688 patient-years. Within lSSC, the Type 2 group had significantly shorter duration of Raynaud’s and more anti-Scl-70 and less anticentromere antibodies. In particular, interstitial lung disease (ILD) was significantly more prevalent in Type 2 group and similar to Type 3. Conclusions. These results appear to confirm that extension of skin involvement within limited SSc may identify two different subsets with clinical and serologic characteristics. 1. Introduction There appears to have been consensus in the past decades in classifying systemic sclerosis (SSc) according to extension of skin involvement as limited and diffuse, using the elbows and knees as “limits” to distinguish between them. However, although this has been used to “dissect” two more or less distinct clinical subsets, there are patients who do not fit this classification and several others have been proposed [1, 2]. The growing demonstration that autoantibodies specific for SSc such as anticentromere, anti-Scl-70 (anti-topoisomerase 1), and more recently a variety of antinucleolar antibodies, particularly anti-RNA polymerase 3, correlate with these subsets and/or visceral manifestations has led to them being used to “predict” clinical subsets in early disease and also raise awareness for the possibility of certain organ involvement (anti-Scl-70 and interstitial lung disease [3, 4], anticentromere associated with digital ulcers [5], debatably pulmonary hypertension [6], and anti-RNA polymerase 3 with renal crisis [7]). Decades ago, Barnett classified SSc as Type 1 (only sclerodactyly), Type 2 (acrosclerosis-distal but may reach up to elbows and/or knees plus face), and Type 3 (diffuse skin involvement) (Figure 1). Patients with Type 2 had an intermediate degree of both skin and organ