Which are the causes of Henoch-Schönlein purpura?

Henoch-Schönlein purpura (also known as IgA vasculitis) is an immune-mediated condition caused by the abnormal deposition of immunoglobulin A (IgA) complexes in the small blood vessels. While the exact trigger remains unknown, it is widely considered to be an exaggerated immune response to an environmental insult, such as an infection, in genetically susceptible individuals.

What triggers Henoch-Schönlein purpura?

The primary mechanism of Henoch-Schönlein purpura involves the body’s immune system mistakenly attacking its own small blood vessels. This is often described as a "misdirected defense." When the immune system encounters a trigger, it creates IgA-containing immune complexes that circulate and settle in the walls of capillaries, causing inflammation (vasculitis). Research suggests that Henoch-Schönlein purpura is frequently preceded by:

• Upper respiratory tract infections (most common)


• Gastrointestinal infections


• Exposure to certain medications or vaccines


• Insect bites or environmental allergens

Is Henoch-Schönlein purpura hereditary?

Henoch-Schönlein purpura is not classified as a strictly hereditary disease, meaning it is not passed directly from parent to child through a single gene mutation. However, there is evidence of a genetic predisposition. Certain human leukocyte antigen (HLA) types may make some individuals more susceptible to developing the condition. It is important to distinguish between a "cause" (the event that initiates the attack) and a "risk factor" (an underlying genetic trait that makes someone more likely to react to that event).

What does current research say about the etiology?

Medical researchers are actively investigating why the body produces abnormal, "galactose-deficient" IgA1 molecules in patients with Henoch-Schönlein purpura. These defective molecules are thought to be the "keys" that unlock the inflammatory process. With over 106 people with Henoch-Schönlein purpura in the DiseaseMaps.org community sharing their lived experiences, researchers are gaining better insights into the diverse triggers and clinical courses of the disease.

Next steps

• Consult a pediatric rheumatologist or nephrologist for a personalized diagnostic plan.


• Monitor for symptoms like skin rashes, joint pain, and abdominal discomfort.


• Join the DiseaseMaps.org community to connect with others who have navigated a Henoch-Schönlein purpura diagnosis.


• Keep a symptom journal to share with your medical team during follow-up visits.

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

References

• NIH Genetic and Rare Diseases Information Center (GARD)


• Orphanet (ORPHA:900)


• OMIM (Online Mendelian Inheritance in Man)


• The Vasculitis Foundation