Henoch-Schonlein purpura, sometimes known as Henoch-Schonlein purpura (HSP), is a form of vasculitis, or inflammation of the blood vessels that occurs as a result of an autoimmune response. Technically, this condition should be spelled Henoch-Schönlein purpura, but Dr. Johann Lukas Schönlein, who first described this condition in the 19th century, is often deprived of the umlaut for it. This condition is most often seen in children, and often resolves on its own without the need for treatment.
There are three telltale signs of Henoch-Schonlein purpura: a characteristic purple rash on the lower extremities, joint pain that is usually centered in the knees and ankles, and stomach cramps. Since these symptoms rarely appear together in association with any other disease, a doctor will often diagnose Henoch-Schonlein purpura based on these symptoms alone. Patients may also experience nausea, vomiting, and bloody diarrhea, and in some cases, kidney involvement occurs.
Although Henoch-Schonlein purpura can often be diagnosed based on symptoms and a physical exam, a doctor may sometimes take a urine sample for testing. The levels of various compounds in the urine can confirm the diagnosis and provide additional information about what is going on inside the patient. If kidney involvement is suspected, urinalysis may be important. A biopsy of the rash may also be taken to confirm that the rash is not being caused by something other than Henoch-Schonlein purpura.
The cause of Henoch-Schonlein purpura is not fully understood. The condition most often arises in people recovering from viral or bacterial infections in the gut, and is thought to be the result of an overzealous immune system. As the blood vessels swell, they can leak, resulting in a purple blotchy rash. People can also experience more serious complications, such as intestinal blockages.
Allergic purpura, as it is also known, is sometimes simply allowed to run its course. If a patient begins to develop complications, anti-inflammatory medications may be prescribed to treat the swollen blood vessels. Some patients may also be given cortisone to reduce the intensity of the immune system response. If complications develop, additional steps can be taken to address them.
Patients who notice the signs of Henoch-Schonlein purpura should call their doctors. The doctor may recommend a wait and see approach, or may ask the patient to make an appointment to be examined. It is especially important to report all symptoms to the doctor, so that the doctor has a full picture of what the patient is experiencing.