The disaccharides constituting chondroitinase-digestible glycosaminoglycan (GAG) in the skin lesions of patients with systemic sclerosis were determined using high-performance liquid chromatography (HPLC). In scleroderma there was an increase in the amount of delta Di-4S(DS), the main disaccharide unit of dermatan sulphate, and a decrease in delta Di-HA, the disaccharide unit of hyaluronic acid, as compared with normal skin from a similar site. The distribution pattern of the main disaccharides constituting chondroitin sulphate and dermatan sulphate in scleroderma differed from that in scars or scleredema.