Purpura, Schönlein–Henoch

Purpura, Schönlein–Henoch (also known as Henoch-Schönlein purpura or HSP) is a form of vasculitis that affects the small blood vessels. It is a condition that primarily affects children, but can also occur in adults. HSP is characterized by a combination of symptoms, including purpura (a rash caused by bleeding under the skin), arthritis (joint pain and swelling), abdominal pain, and kidney involvement. The exact cause of HSP is unknown, but it is thought to be related to an abnormal response of the immune system, often following an infection of the upper respiratory tract.

Symptoms and Diagnosis

The hallmark symptom of HSP is a purpuric rash, which appears as red or purple spots on the skin, typically on the lower legs and buttocks. These spots are a result of bleeding from small blood vessels into the skin. Other common symptoms include abdominal pain, which can be severe and is caused by inflammation in the gastrointestinal tract; joint pain and swelling, most often affecting the knees and ankles; and kidney involvement, which can range from mild to severe and may lead to nephritis or renal failure.

Diagnosis of HSP is primarily based on the clinical presentation. Laboratory tests, including blood tests and urine tests, may be used to assess kidney function and to rule out other conditions. A biopsy of the skin or kidneys may be performed in some cases to confirm the diagnosis.

Treatment

Treatment for HSP is mainly supportive and focuses on relieving symptoms. Nonsteroidal anti-inflammatory drugs (NSAIDs) may be used to alleviate joint pain and swelling. In cases of severe abdominal pain or significant kidney involvement, corticosteroids may be prescribed. It is also important for patients to maintain adequate hydration and rest.

Most individuals with HSP recover completely without any long-term complications. However, kidney involvement can lead to chronic kidney disease in a small percentage of cases. Regular follow-up with a healthcare provider is important to monitor kidney function and to manage any complications that may arise.

Epidemiology

HSP is the most common form of vasculitis in children, but its incidence in adults is much lower. The condition typically occurs in late fall, winter, or early spring, coinciding with the peak times for upper respiratory tract infections. There is a slight male predominance in the pediatric population.

Prognosis

The prognosis for individuals with HSP is generally good, especially for children. Most symptoms resolve within a few weeks, although they can recur in some cases. Long-term kidney damage is the most serious potential complication, but it is relatively rare.