What is henoch-purpura deasease?

Vasculitis : HSP is a vasculitis type of disease.

Blood vessels: An inflammation of blood vessels causing a rash, abdominal pain and kidney problems https://en.wikipedia.org/wiki/Henoch%E2%80%93Sch%C3%B6nlein_purpura

Inflammation of smal: Inflammation and bleeding from small blood vessels in skin, joints, intestines, and kidneys. There is a striking hemorrhagic skin rash. There may be pain in joints and abdomen. There may be blood in the urine. Mostly children. Most seem to follow a respiratory infection as an abnormal immune phenomenon. Goes away after about a month. Steroid therapy may be used but benefit not clear. Kidney damage