Well sometimes we must search further to get the information we want to find out. So the answer to your question regarding Lymphocytic vasculitis would be something like this.
First of all this is inflammation of blood vessels due to infiltration of blood vessel walls with lymphocytes. Lymphocytes can cause raised skin welts which can be very tender and painful. Sometimes it can happen that the skin remains darkened after the problem is resolved.
Most common symptoms of lymphocytic vasculitis are pain, tenderness, purpura, increased pigmentation and raised red skin patches.
Unfortunately the cure is not known and some researches are showing that certain therapies could be beneficial but there is no scientific proof of this.