Acute UVB-induced epidermal changes assessed by multiphoton laser tomography

Background In vivo multiphoton tomography (MPT) of human skin has become a valuable tool for non-invasive examination of morphological and biophysical skin properties and their alterations. So far, skin changes after UVB irradiation were mainly evaluated clinically and histologically. The present study aimed at non-invasive imaging of histological changes during acute UVB irradiation by multiphoton laser tomography. Methods In 10 volunteers, five areas were irradiated once with an erythematous UVB dose. Multiphoton measurements were performed four times, i.e. before irradiation (baseline), and 24, 48 and 72 h after irradiation, respectively. The data were evaluated for changes of epidermal pleomorphy, spongiosis, pigmentation and thickness. Results The four parameters were altered significantly by acute UVB irradiation, i.e. epidermal pleomorphy, spongiosis, pigmentation and thickness increased within 72 h after irradiation. Conclusion Thus, the study has shown that typical epidermal changes induced by acute UVB irradiation can be evaluated by MPT.