There are divergent opinions as to whether atrophoderma of Pasini and Pierini (APP) is a nosologic entity or a primary atrophic morphoea. In this study, we used high performance liquid chromatography to analyse the skin disaccharide contents of glycosaminoglycan (GAG) in two patients with APP and compared the results with those from a typical atrophic morphoea patient. Perilesional uninvolved skin was used as a control in each patient. In the atrophic phase morphoea, both the total amount of disaccharide per skin punch-biopsy and the amount of DeltaDi-4S(DS) - the main disaccharide unit of dermatan sulphate - per mg dry weight were increased. These changes were consistent with sclerotic phase morphoea. In contrast, the total amount of disaccharide per skin punch-biopsy was decreased and the amount of DeltaDi-4S(DS) per mg dry weight was decreased or unchanged in APP. Our results suggest that GAG metabolism in APP may be unique and quite different from that in morphoea.