Immunoglobulin A vasculitis (IgAV), formerly Henoch-Schönlein purpura, is the most common systemic vasculitis of childhood and is typically self-limited. Renal risk stratification frequently relies on the presence of hematuria or proteinuria; however, early disease severity may not be detected by urinalysis alone. We present a previously healthy seven-year-old boy with palpable purpura and joint pain. The diagnosis was made clinically based on the presence of nonthrombocytopenic palpable purpura in the setting of arthralgia. He was diagnosed with IgAV after initially reassuring laboratory findings, including normal renal function and repeatedly negative urinalysis. Despite this, his clinical course rapidly progressed to persistent vomiting, abdominal pain, gastrointestinal bleeding, scrotal edema, and sustained hypertension requiring hospitalization and pharmacologic management. Repeated urinalyses during the acute illness remained negative for hematuria and proteinuria despite the development of hypertension and severe systemic involvement. This case highlights a clinical pitfall: although IgAV is primarily a clinical diagnosis based on characteristic findings such as palpable purpura and systemic symptoms, early laboratory studies, including urinalysis, may appear reassuring despite evolving systemic involvement. Close follow-up with serial blood pressure monitoring and urinalysis is essential during the disease course, whether initial laboratory findings are reassuring or abnormal.
Escobar et al. (Mon,) studied this question.