Purpura Diagnoses in my 9 year old

Has anyone had a child that was diagnosed with Purpura?

My 9 year old was recently diagnosed with Purpura and I am curious to know if anyone has had experience with their child having this as well? The Dr has scared the crap out of me with these “underlying causes” and I just need to know if this is something that will potentially get better or if I really need to brace myself and my family for more serious conditions. I have made sure to get testing done too… and deeply considering getting a second opinion because this dr made it seem like my baby has a very serious problem and will die before he makes it to high school. Please please please give me some solace that I won’t be losing my kid.