Definition
Purpura Schönlein-Henoch is an inflammation of small blood vessels (vasculitis) triggered by the immune system and occurs mainly in children under 10 years of age. Various organs can be affected, such as the skin, gastrointestinal tract, kidneys or joints. Reddening and bleeding of the skin is noticeable, as the vessels become more permeable due to the inflammation. It often occurs after an infection of the upper respiratory tract.
Causes
The exact pathogenesis of Purpura Schönlein-Henoch is unknown. However, it often occurs after viral or bacterial inflammation of the upper respiratory tract, such as influenza, and after taking medication. Especially antibiotics, anti-inflammatory drugs and diuretics can serve as triggers.
Other possibilities are diseases of the immune system, insect bites or even tumors. These factors suggest a reaction of the immune system as the cause. A genetic predisposition can also play a role.
This leads to the deposition of antibodies, the immunoglobulins A (IgA), in the vessel walls. The IgA immune complexes now formed there lead to inflammation (vasculitis) and thus to damage to the vessels. As a result, the blood from the vessels reaches the surrounding tissue and the typical bleeding and reddening occurs. This reaction often occurs in the skin, but also in the kidneys, joints or gastrointestinal tract.
Diagnosis
There is no test or blood value with which the Purpura Schönlein-Henoch can be detected directly. The disease is diagnosed by the specialist by means of anamnesis and examination of the child. Special attention must be paid to the typical punctiform skin bleeding (petechiae) and skin redness.
Since the disease is often preceded by an infection of the respiratory tract, this should be checked. Further examinations include blood sampling, although this is usually inconspicuous, urine analysis to determine kidney involvement, stool analysis and an ultrasound of the abdomen. Occasionally an MRI is also performed to check whether the central nervous system is affected by the vascular inflammation. The main purpose of these examinations is to rule out other diseases.
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