What Is Henoch-Schönlein Purpura Nephritis and How Does It Affect the Body?

Understanding Henoch-Schönlein Purpura Nephritis (HSPN)

Henoch-Schönlein purpura nephritis (HSPN) is a form of vasculitis—an inflammation of the small blood vessels—that primarily affects children but can also occur in adults. This condition arises when the immune system mistakenly attacks blood vessels, leading to widespread symptoms across multiple organ systems. The hallmark of HSPN is the development of purpuric skin lesions, typically appearing as raised, non-blanching rashes on the lower extremities and buttocks.

Common Symptoms and Systemic Involvement

Skin manifestations are often the first noticeable sign. These include palpable purpura—small, red or purple spots that do not fade under pressure—commonly concentrated on the legs and buttocks. While the rash itself isn't usually painful, it signals underlying vascular inflammation that may extend beyond the skin.

Gastrointestinal Complications

Many patients experience abdominal pain, which can range from mild discomfort to severe cramping. This symptom frequently leads to misdiagnosis as acute appendicitis or another surgical abdomen condition, resulting in unnecessary referrals to general surgery. Additional gastrointestinal issues may include nausea, vomiting, and in rare cases, intestinal bleeding or intussusception.

Musculoskeletal Symptoms

Joint involvement is another key feature, with arthralgia—joint pain—commonly affecting the knees and ankles. Though swelling and tenderness may occur, permanent joint damage is uncommon. These symptoms often mimic juvenile arthritis, further complicating early diagnosis.

Kidney Involvement: The Defining Feature of HSPN

The most concerning aspect of this condition is its impact on the kidneys. When Henoch-Schönlein purpura progresses to nephritis, it means the glomeruli—the filtering units of the kidneys—are inflamed. This can result in several clinical signs:

• Blood in the urine (hematuria), often microscopic but sometimes visible
• Proteinuria, where excess protein leaks into the urine
• Elevated serum creatinine levels, indicating reduced kidney function
• In severe cases, progression to acute or chronic kidney disease

Diagnosis and Monitoring

Early detection is crucial. Physicians typically use urinalysis, blood tests, and sometimes kidney biopsy to confirm the extent of renal involvement. Children with mild symptoms may only require observation, while those with significant proteinuria or impaired kidney function might need immunosuppressive therapy.

Long-Term Outlook and Management

While many cases resolve spontaneously within weeks to months, a subset of patients—especially those with persistent proteinuria or hypertension—require long-term follow-up. Pediatric nephrologists often monitor these individuals for years to prevent complications such as chronic kidney disease or end-stage renal failure.

In conclusion, Henoch-Schönlein purpura nephritis is a multisystem disorder that demands careful evaluation and management. Awareness of its diverse presentation—from skin rashes to kidney dysfunction—can lead to earlier diagnosis, reduce misdiagnosis, and improve patient outcomes significantly.