What disease causes allergic purpura

Henoch-Schönlein purpura is familiar to many people. It is a type of allergic vasculitis that can occur in both childhood and adulthood. Many people don’t know what causes allergic purpura. Generally speaking, allergic purpura is also related to autoimmunity.

1. Autoimmunity (30%):

Due to the body's allergic reaction to certain allergens, the permeability and fragility of capillaries increase, leading to bleeding and edema of subcutaneous tissue, mucous membranes and internal organs. Allergens can be caused by many factors, but it is often difficult to find the exact cause of each specific case. It is usually believed that it may be related to multiple inducing factors, but the direct pathogenic factor is often difficult to confirm.

2. Infection factors (40%):

The most common bacterial infection is β-hemolytic streptococcus, followed by Staphylococcus aureus, Mycobacterium tuberculosis, Salmonella typhi, Pneumococcus and Pseudomonas, etc. Upper respiratory tract inflammation is more common, and can also be seen in pneumonia, tonsillitis, scarlet fever, bacillary dysentery, urinary tract infection, impetigo, tuberculosis and focal infection (skin, teeth, mouth, middle ear), etc. Viral infections include rubella, influenza, measles, chickenpox, mumps, hepatitis, etc. Parasitic infections can also cause this disease, with ascariasis being the most common, as well as hookworms, whipworms, red worms, schistosoma japonicum, Trichomonas vaginalis, and Plasmodium infections.

3. Other factors (20%):

Insect bites, plant pollen, cold, trauma, menopause, tuberculin test, vaccination, mental factors, etc. can all cause it. In addition, there are reports of allergic purpura in hemodialysis patients, patients after lymphoma chemotherapy and patients with Guillain-Barre syndrome.