Qualitative thermograhic analysis of psoriatic skin lesions

Psoriasis vulgaris affects about 2% of the human population all over the world. The aim of this study was to evaluate usefulness of thermography in estimation of psoriatic lesion activity. A series of patients with plaque type psoriasis vulgaris were included. ThermaCam INFRAMETRICS 290E thermocamera with temperature resolution of 0.1°C was employed. Both visual and thermal images of the patients were taken. Clinical severity of the lesions was evaluated by Plaque Severity Score (PSS, scale 0-4). We discovered higher temperature over psoriatic plaques and further vastly expanding beyond the visually documented borders of the lesions thus not corresponding to the individual shapes of the lesions, suggested that those lesions presented an active phase of the disease (developing over the last 2-3 weeks). To the contrary, areas of the increased temperature over chronic psoriatic plaques (already developed at least 8 weeks before without signs of visible progression) corresponded quite well to the shapes of clinically visible lesions i.e. single lesions could be differentiated within the area of the increased temperature. The above observations would allow to introduce more aggressive local treatment only to the selected lesions thus as much as possible sparing the rest of them from probable side-effects.