Urine protein 2+ in purpura is not necessarily nephritis. At this time, high urine protein may be purpura nephritis, or may be combined with other aspects of the disease such as urinary stones, urinary tract infection. 1. Purpura nephritis: it is the manifestation of renal damage when allergic purpura occurs. Renal manifestations are mainly hematuria and proteinuria; extra-renal manifestations are mainly abdominal pain, blood in stool, skin purpura, joint swelling and pain. Its etiology can be caused by viruses and parasites, bacteria and other infections caused by allergic reactions or insect bites, cold stimulation, plant pollen and other factors. 2. Urinary stones, urinary tract infection: patients with purpura may also be combined with urinary stones or urinary tract infection, at this time there may be the manifestation of urinary protein 2 +, at the same time may be combined with urinary difficulties, urinary incontinence, lumbar pain, urinary pain, urinary frequency, urinary urgency, fever and other symptoms. Allergic purpura urinary protein 2 +, there are many reasons, it is recommended that patients go to the regular hospital in a timely manner, improve the relevant examination, diagnosis and treatment under the guidance of the physician, so as not to delay the condition.