How is the skin affected in Systemic Sclerosis?
The hallmark of scleroderma is thickened skin, thought to be due to the excessive production of normal type I collagen by a subset of fibroblasts along with the accumulation of glycosaminoglycan and fibronectin in the extracellular matrix.
There is loss of sweat glands and hair loss in the areas of tight skin. Although patients may seem to have areas of clinically involved and uninvolved skin, immunohistochemistry and other analytic techniques have demonstrated that all skin tends to be abnormal.
Skin thickening begins on the fingers and hands in virtually all cases of SSc. When skin thickening begins elsewhere, morphea, eosinophilic fasciitis, or another scleroderma mimic (: Scleroderma Mimics) should be considered.
The progression of skin tightening can be quite variable among patients. The modified Rodnan skin score (mRSS) is used clinically and in clinical trials to quantify skin involvement.
The score is calculated by scoring 17 areas on the body and each area is graded from 0 (no involvement) to 3 (severe involvement), for total possible score of 51. Skin scores over 15 to 20 and rapid progression (within 1st year) indicate more severe skin thickening.
Most patients’ skin, with no therapy, softens or atrophies over 3 to 10 years