Henoch-Schonlein Purpura (HSP) is a form of small-vessel vasculitis characterized by the deposition of immunoglobulin A (IgA) in blood vessels, leading to inflammation and tissue damage. The condition primarily affects the skin, gastrointestinal system, kidneys, and joints. Although HSP can occur at any age, it is most commonly diagnosed in children under the age of 10, particularly during the colder months of fall, winter, and spring.
Pathophysiology
The hallmark of HSP is the deposition of IgA in the small blood vessels, causing immune complex-mediated vasculitis. The deposition of these complexes leads to the activation of complement proteins and the recruitment of inflammatory cells, which contribute to the inflammatory response. The inflammatory process affects various organs, including the skin, kidneys, gastrointestinal tract, and joints. The specific pathogenesis of IgA deposition in HSP remains under investigation, though it is thought that genetic predisposition, environmental factors, and immune system dysregulation play important roles.
Clinical Manifestations
HSP typically presents with a combination of symptoms affecting multiple systems:
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Skin Involvement: The most characteristic symptom of HSP is a palpable purpuric rash, often described as small, raised, red or purple spots that can be felt with the fingertips. These lesions primarily affect the lower extremities, especially the shins and buttocks, and tend to appear symmetrically. In severe cases, the rash may develop into larger ecchymoses or ulcerations.
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Gastrointestinal Symptoms: Abdominal pain, nausea, vomiting, and gastrointestinal bleeding are common in children with HSP. In some cases, this can lead to intussusception, a condition where part of the intestine folds into itself, requiring prompt medical intervention.
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Joint Involvement: Joint pain and swelling, particularly in the larger joints such as the knees and ankles, are also frequently seen. These symptoms are often self-limiting, though they can cause significant discomfort during the acute phase of the disease.
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Renal Involvement: Kidney manifestations, including hematuria (blood in the urine) and proteinuria (protein in the urine), can occur in some patients. Renal involvement, if severe, may lead to long-term complications such as chronic kidney disease, though this is less common.
Diagnosis
The diagnosis of HSP is based on clinical findings and laboratory tests. In many cases, the characteristic purpuric rash and history of recent upper respiratory infection are sufficient for diagnosis. However, in cases where the diagnosis is uncertain, a skin biopsy may be performed. Histological examination typically reveals leukocytoclastic vasculitis, with IgA deposition in the small blood vessels. Urinalysis is essential to monitor for kidney involvement, and abdominal imaging may be necessary if gastrointestinal complications are suspected.
Treatment
Management of HSP is primarily symptomatic and aimed at alleviating the patient’s discomfort. The treatment plan may vary based on the severity of the symptoms and the organs involved:
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Supportive Care: Most cases of HSP are self-limited, and supportive care is usually sufficient. This includes adequate hydration, rest, and pain control. For mild joint pain, nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen can be used.
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Corticosteroids: For more severe symptoms, such as extensive skin involvement, significant abdominal pain, or renal involvement, oral corticosteroids such as prednisone are commonly prescribed. These medications help reduce inflammation and manage more serious manifestations of the disease.
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Other Immunosuppressive Agents: In rare cases, especially if the disease leads to chronic kidney disease or other serious complications, additional immunosuppressive therapy such as cyclophosphamide or rituximab may be considered. However, these treatments are typically reserved for severe or refractory cases.
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Management of Gastrointestinal Symptoms: For patients with significant abdominal pain or gastrointestinal bleeding, treatment may include supportive care and, if necessary, interventions to address complications like intussusception.
Prognosis
The prognosis for most children with HSP is excellent, with the majority of patients experiencing full recovery without long-term complications. Renal involvement is seen in approximately one-third of patients, but most cases resolve without permanent kidney damage. However, a small proportion of patients may develop chronic kidney disease, particularly those with more severe initial renal involvement. Follow-up monitoring of kidney function is recommended for patients with significant renal manifestations. Joint pain typically resolves on its own, and the skin rash generally improves within a few weeks.
Conclusion
Henoch-Schonlein Purpura is a vasculitis primarily affecting children, with characteristic symptoms including a purpuric rash, gastrointestinal symptoms, joint pain, and potential kidney involvement. While most cases resolve with supportive care and corticosteroid therapy, some patients may experience long-term complications, particularly related to renal function. Early diagnosis and appropriate management are key to ensuring a good prognosis, and ongoing research into the pathophysiology and treatment options for HSP will continue to improve patient outcomes.
References
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Gowda, S. P., & Nadiminti, K. K. (2021). Henoch-Schonlein purpura: A comprehensive review. Journal of Pediatric Health Care, 35(2), 172-178. https://doi.org/10.1016/j.pedhc.2020.08.008
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He, Y., Zhang, R., & Xue, J. (2018). Gastrointestinal involvement in Henoch-Schonlein purpura: A review of 112 cases. Pediatrics International, 60(11), 975-980. https://doi.org/10.1111/ped.13731
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Samarasekera, E. J., Jenkins, P., & Gunaratne, R. (2020). Renal involvement in Henoch-Schonlein purpura: Diagnosis and management. Clinical Kidney Journal, 13(6), 922-931. https://doi.org/10.1093/ckj/sfaa032
