I just went on emedicine to find out more about leukocytoclastic vasculitis, which I have been diagnised with recently. I was told the cause of my leukocytoclastic vasculitis is unknown, but now it says on eMedicine that this is normaly - apparently, over half of patients never find out what caused their leukocytoclastic vasculitis! What really frustrates me is that the article mentions that there is no way to predict if and how the leukocytoclastic vasculitis will spread.