Usefulness of surface topography analysis in psoriatic skin

The study of skin reliefs attracted the attention of dermatologists because it may reflect development, assembly and functional activity of the stratum corneum--and therefore of the entire epidermis. Psoriasis is characterized by a deep alteration of surface texture: and this can be related to the severity of the disease. In this work we studied, by means of skin profilometry, the roughness parameters that better describe the distinctive features of psoriatic skin topography and the modification of psoriatic surface after topical therapy. For this purpose we analyzed psoriatic skin reliefs using silicone rubber replicas both before therapy and after coal-tar topical application. A statistically significant difference between uninvolved and psoriatic skin for Ra- but not for Rz- values was observed in replicas made before therapy. After therapy, replicas showed no significant difference either for Ra or for Rz values. The profilometric analysis of psoriatic skin can be considered a useful method to characterize psoriatic plaque and the improvement obtained by topical therapy.