<unk>  is a disease that involves purple spots on the skin, joint pain, gastrointestinal problems, and glomerulonephritis (a type of kidney disorder).
Henoch-Schönlein purpura
Golfer's vasculitis
Hennekam syndrome
Roussy–Lévy syndrome
Serum sickness
Hemolytic-uremic syndrome
Cold agglutinin disease
Hemorrhagic fever with renal syndrome 