What are the key clinical features to consider when diagnosing Henoch-Schönlein Purpura in children?

Key clinical features for diagnosing Henoch-Schönlein Purpura (HSP) in children include:

• Palpable purpura: This is the hallmark feature, typically non-blanching, raised purpuric rash predominantly on the lower limbs and buttocks, without thrombocytopenia or coagulopathy NICE CG84 Castañeda et al. 2024.
• Arthritis or arthralgia: Joint pain and swelling, especially affecting knees and ankles, is common and often transient NICE CG84 Bayındır et al. 2024.
• Abdominal pain: Colicky abdominal pain due to gastrointestinal vasculitis, sometimes accompanied by gastrointestinal bleeding, is a key systemic feature NICE CG84 Castañeda et al. 2024.
• Renal involvement: Hematuria and/or proteinuria indicating glomerulonephritis may be present, requiring urine analysis as part of diagnosis and monitoring NICE CG84 Hammad et al. 2023.
• Other systemic symptoms: Mild fever and malaise can occur but are not specific NICE CG84 Bayındır et al. 2024.

Diagnosis is clinical, based on the characteristic purpuric rash plus one or more of the systemic features above, with exclusion of other causes of purpura NICE CG84. Recent literature emphasizes the importance of IgA deposition in small vessel walls as a pathognomonic histopathological finding, though biopsy is rarely needed in typical cases Castañeda et al. 2024. Early recognition of these features in children presenting with purpura is essential for appropriate management and monitoring for complications NICE CG84 Hammad et al. 2023.