Symptoms of allergic purpura

Allergic purpura, which can be found at [this link](http://www.120.net/jibing/73keclgaszpkneca.html), is a type of allergic vasculitis that predominantly manifests with skin symptoms. It commonly affects children and adolescents, with a male-to-female patient ratio of approximately 2:1. Allergic purpura primarily affects the skin, kidneys, joints, and gastrointestinal tract, and its main symptoms include:

1. Hypertension. Usually mild hypertension occurs, while marked hypertension often indicates a poor prognosis.

2. Hematuria, either visible to the naked eye or only under a microscope, may persist or occur intermittently, worsening after infection or an episode of purpura. Most cases are accompanied by varying degrees of proteinuria.

3. Proteinuria varies in severity and does not necessarily correlate with the severity of hematuria. Proteinuria is usually moderate, and the drop in plasma protein levels is more significant than the severity of proteinuria, possibly due to protein leakage from other areas such as the gastrointestinal tract or subcutaneous tissues. Some cases may present as nephrotic syndrome or acute nephritis syndrome, with the latter showing relatively less obvious edema and hypertension.

4. A few patients experience swelling, mostly mild. Swelling during the acute phase is often associated with elevated blood pressure, indicating more extensive lesions. The swelling is related to proteinuria, protein loss through the gastrointestinal tract, and changes in capillary permeability. Additionally, patients often experience joint pain, skin purpura, abdominal pain, and general discomfort. Renal function is generally normal, but in some cases, there may be transient elevations in serum creatinine and blood urea nitrogen. Serum tests show increased IgA and IgM in most cases, while IgG remains normal. C3 and CH50 are mostly normal, and many cases show an increase in cold globulin in the blood.

The exact cause of allergic purpura is still unclear, but it is related to allergic factors. Therefore, maintaining good living habits in daily life and avoiding exposure to allergens for those with a history of allergies can effectively prevent allergic purpura. If the disease occurs, it is important to take care of the skin and avoid frequent scratching to prevent skin damage.