BACKGROUND: Systemic sclerosis (SSc) is a multisystem autoimmune disease, which is classified into a diffuse cutaneous (dcSSc) and a limited cutaneous (lcSSc) subset according to the skin involvement.

• 背景：系统性硬化症是一种多系统性自身免疫性疾病，根据皮肤受累可分为弥漫皮肤型和局限皮肤型两个亚型。