From the Guidelines
HSP stands for Henoch-Schönlein Purpura, now more commonly called IgA Vasculitis, an autoimmune condition characterized by inflammation of small blood vessels. This condition primarily affects children between ages 2-10, though it can occur in adults, and is caused by abnormal immune system reactions where IgA antibodies are deposited in blood vessel walls 1. The classic symptoms of HSP include:
- A distinctive purplish rash (purpura) typically on the buttocks and lower legs
- Joint pain
- Abdominal pain
- Sometimes kidney involvement, with prognosis being worse with protein excretion of 1 g/d or more, as suggested by limited data from retrospective case series 1. Most cases resolve on their own within 4-6 weeks without specific treatment, though pain management with acetaminophen or ibuprofen is often recommended. More severe cases, especially those with significant kidney involvement, may require corticosteroids like prednisone, although the long-term benefit of steroid therapy for nephrotic-range or persistent proteinuria in adults has not been proved 1. It's essential to monitor kidney function after diagnosis, as approximately 1-2% of patients may develop long-term kidney problems. Given the potential for severe initial renal involvement and risk of progression in adults, it is crucial to closely monitor and manage HSP cases, especially in adults, to prevent long-term kidney damage.
From the Research
Definition of HSP
- Henoch-Schönlein purpura (HSP) is a systemic, immune complex-mediated, small-vessel leukocytoclastic vasculitis characterized by nonthrombocytopenic palpable purpura, arthritis, and abdominal pain 2.
- It is also known as immunoglobulin A (IgA) vasculitis, a systemic hypersensitivity vasculitis caused by the deposition of immune complexes in small blood vessels, including the renal glomeruli and mesangium 3.
- HSP is a multisystem immunoglobulin A-mediated vasculitis with a self-limited course affecting the skin, joints, gastrointestinal tract, and kidneys 4.
Clinical Features and Diagnosis
- The clinical features of HSP include purpura, arthralgia, arthritis, abdominal pain, and renal involvement 2, 3.
- Detection of IgA deposition in small blood vessels and the renal glomeruli is diagnostic in most cases 3.
- A skin biopsy may be necessary for diagnosis, especially in adults and very young children 4.
Epidemiology and Prognosis
- HSP is the most common vasculitis in children, but it can also occur in adults 2, 5.
- The overall prognosis in HSP is excellent, but the long-term morbidity depends on the renal and neurologic involvement 4.
- IgA vasculitis spontaneously resolves in 94% of children and 89% of adults, making supportive treatment the primary management strategy 2.