What is Henoch-Schönlein purpura

Henoch-Schönlein purpura (now formally known as IgA vasculitis) is a systemic condition characterized by the inflammation of small blood vessels, which causes blood to leak into the skin, joints, intestines, and kidneys. It is the most common form of childhood vasculitis and typically manifests as a distinctive reddish-purple rash, though its impact on the kidneys requires careful medical monitoring.

What are the primary symptoms of Henoch-Schönlein purpura?

The hallmark of Henoch-Schönlein purpura is a palpable purpura—raised, reddish-purple spots usually found on the legs, buttocks, and elbows. Beyond the skin, the disease affects multiple systems, often causing joint pain (arthritis), abdominal pain due to inflammation of the gut wall, and potential kidney involvement (nephritis). In our DiseaseMaps community, 106 people with Henoch-Schönlein purpura have shared their experiences, highlighting that while the skin rash is the most visible sign, the internal organ involvement is what necessitates specialized clinical follow-up.

Who is typically affected by Henoch-Schönlein purpura?

Henoch-Schönlein purpura most frequently affects children between the ages of 3 and 15, though it can occur at any age. It is slightly more common in males than in females. While the condition can occur year-round, it is often noted to follow upper respiratory tract infections, suggesting an immune system trigger. Key clinical features include:

• Palpable purpura: Present in nearly 100% of cases.


• Arthritis or arthralgia: Occurs in approximately 75% of patients.


• Abdominal involvement: Affects roughly 60% of patients, sometimes leading to complications.


• Renal involvement: Seen in 20% to 50% of cases, requiring long-term urine monitoring.

What causes Henoch-Schönlein purpura?

The underlying mechanism of Henoch-Schönlein purpura involves the deposition of immunoglobulin A (IgA) complexes in the walls of small blood vessels (capillaries). This triggers an inflammatory response known as leukocytoclastic vasculitis. Unlike other forms of vasculitis, Henoch-Schönlein purpura is specifically identified by these IgA deposits, which distinguishes it from conditions like Henoch-Schönlein purpura mimics, such as idiopathic thrombocytopenic purpura (ITP).

Next steps

• Consult a pediatric rheumatologist or a nephrologist if you suspect symptoms of Henoch-Schönlein purpura.


• Maintain a log of any new skin spots or changes in urine color to share with your medical team.


• Join our community at DiseaseMaps.org to connect with others who have navigated the diagnosis and management of Henoch-Schönlein purpura.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): IgA Vasculitis


• Orphanet: Henoch-Schönlein purpura


• American College of Rheumatology: IgA Vasculitis (Henoch-Schönlein Purpura)


• Vasculitis Foundation: IgA Vasculitis (HSP)