How many types of allergic purpura are there?

Allergic purpura is a common clinical disease, which is also called self-limiting acute hemorrhagic disease. Allergic purpura can invade the skin. There are many types of allergic purpura, and many people are concerned about how many types of allergic purpura there are. The most common of these is the skin type.

1. Skin type: the most common type. The main manifestation is skin hemorrhagic rash. The rash is more common below the buttocks, appears in batches, is symmetrically distributed, varies in size, and is of varying ages. It is maculopapular purpura or exudative erythema that is raised above the skin surface. May be accompanied by urticaria, edema, erythema multiforme, ulcers or necrosis.

2. Joint type: Purpura causes swelling and pain in the anterior/posterior joints, most commonly in the knees, ankles, elbows, and wrists. The pain may be migratory and no deformity will remain after healing.

3. Abdominal type: more common in children. There is abdominal pain before and after the onset of purpura, which may be accompanied by nausea, vomiting, and bloody stools, but there is no abdominal muscle tension or rebound pain, and the symptoms and signs are separated. May also be complicated by intussusception. When abdominal pain is severe, care should be taken to distinguish it from acute abdomen.

4. Purpura nephritis: It is more common in children and may occur before or after the onset of purpura. About 30% of children will develop kidney damage, often manifested as macroscopic or microscopic hematuria and positive urine protein. Most cases occur 4-8 weeks after onset. A few cases may present with persistent nephritis, nephrotic syndrome, chronic glomerulonephritis, and rapidly progressive nephritis.

5. Mixed type: Two or more of the above four types exist in combination.

6. Other rare types: In a few cases, the lesions involve the central nervous system, which may cause severe headache, dizziness, vomiting, irritability, delirium, convulsions, paralysis and coma. A very small number of patients may suffer from myocarditis, pleurisy, pulmonary hemorrhage, asthma, laryngeal edema, iritis, etc.