Solar Purpura Induced by UVB Irradiation

Abstract

We report three cases of solar purpura (SP), which has been reported as a rare condition showing petechiae after the intense sun exposure. All three cases developed pinpoint-sized, purpuric eruptions after intense sun exposure with or without papular or macular erythematous eruptions. These purpuric eruptions were reproduced by UVB photoprovocation tests in all three cases. Although the mechanisms of this peculiar form of photosensitivity still remain unclear, photo-induced products might play some role in the induction of endothelial cell damage, resulting in extravasation of red blood cells.