Henoch-Schönlein purpura nephritis and allergic purpura are not infectious diseases; there is no contagious element involved. Henoch-Schönlein purpura nephritis is actually kidney damage caused by allergic purpura, which is an allergic disease itself. Patients suffer from an abnormal immune response in the body’s immune system after coming into contact with allergenic drugs or foods, leading to necrotizing vasculitis. This disease is unrelated to pathogens. Generally, there is no direct damage to the kidneys caused by a specific pathogen in this disease, nor do patients carry pathogens that can cause Henoch-Schönlein purpura nephritis, such as bacteria or viruses, thus making the disease non-contagious.