Allergic purpura is a systemic vascular disease with predominant involvement of small blood vessels. The main clinical manifestations of allergic purpura are subcutaneous or submucosal bleeding, usually in the lower extremities. It can be associated with joint pain, acute abdominal pain, gastrointestinal bleeding and kidney damage. The disease can be triggered by a number of factors, with colds being one of the most common ones. For some special patients, especially some allergic people, contact with some allergens such as pollen, seafood, insects, and even excessive fatigue can lead to allergic purpura, it should be noted that injection of some antibacterial agents or vaccines can also trigger this disease. The actual fact is that you can find a lot of people who are not able to get a good deal on this kind of things.