IgA Vasculitis (Henoch-Schönlein Purpura)

Definition AND EtiologyTop

IgA vasculitis (IgAV) (previously known as Henoch-Schönlein purpura) is a small-vessel vasculitis characterized by the presence of immune deposits (mainly IgA1), which involves small vessels (predominantly capillaries, venules, or arterioles). It primarily affects children (~75% cases in children aged 2-11 years), although it can also present in adults, where the prognosis is generally worse.

Clinical Features and Natural HistoryTop

The onset of IgAV is acute. In most cases it develops within 1 to 2 weeks of a viral upper respiratory tract infection but sometimes follows a gastrointestinal (GI) infection. IgAV may also be associated with other diseases, for instance, liver disease, inflammatory bowel disease, or ankylosing spondylitis. IgAV characteristically involves a triad of palpable purpura, abdominal pain, and arthritis.

Signs and symptoms:

1) Cutaneous manifestations (in ~90% of patients): Macular rash or urticaria evolving into palpable purpura, usually located on the lower extremities and buttocks. Lesions develop in a single episode or are recurrent and accompany other symptoms.

2) Joint manifestations: Arthralgia involving mainly joints of the lower limbs (knees and ankles), occasionally with other symptoms of arthritis.

3) GI manifestations: Abdominal pain, usually diffuse, worsening after meals, and associated with intestinal vasculitis (most frequently affecting the small intestine). Occasionally bloody diarrhea.

4) Renal manifestations: Most frequently microscopic hematuria.

5) Other manifestations: Rarely, pulmonary (hemoptysis) and nervous system involvement (headache, seizures).

In children the disease tends to have a mild course, with a complete recovery observed within a few weeks or months. Cutaneous lesions resolve within 2 weeks. In adolescents and adults the course is more severe due to more frequent renal involvement; in ~30% of patients the disease progresses to renal failure.

DiagnosisTop

Diagnosis is based on clinical symptoms and histologic examination of skin biopsy specimens (perivascular and vascular IgA deposits in small vessels). The disease may be limited to skin or kidneys (in the latter case IgA nephropathy is diagnosed). Kidney biopsy should only be considered in patients with severe proteinuria, hematuria, active sediment, or with renal failure.

TreatmentTop

As most cases of IgAV are self-resolving, supportive therapy is the mainstay of treatment.Evidence 1Weak recommendation (benefits likely outweigh downsides, but the balance is close or uncertain; an alternative course of action may be better for some patients). Moderate Quality of Evidence (low confidence that we know true effects of the intervention). Quality of Evidence lowered due to the presence of retrospective observational studies, indirectness, imprecision, and risk of bias. Blanco R, Martínez-Taboada VM, Rodríguez-Valverde V, García-Fuentes M, González-Gay MA. Henoch-Schönlein purpura in adulthood and childhood: two different expressions of the same syndrome. Arthritis Rheum. 1997 May;40(5):859-64. PubMed PMID: 9153547. Symptomatic treatment is sufficient in patients without features of GI or renal involvement.

Early use of oral glucocorticoids (1-2 mg/kg prednisone per day for 2 weeks) may be used to improve joint and abdominal pain symptoms. Oral glucocorticoids do not prevent renal disease but can improve renal outcomes.Evidence 2High Quality of Evidence (high confidence that we know true effects of the intervention). Ronkainen J, Koskimies O, Ala-Houhala M, et al. Early prednisone therapy in Henoch-Schönlein purpura: a randomized, double-blind, placebo-controlled trial. J Pediatr. 2006 Aug;149(2):241-7. PubMed PMID: 16887443. Avoid nonsteroidal anti-inflammatory drugs (NSAIDs) in patients with renal involvement. In the case of cutaneous manifestations dapsone 100 mg/d may be administered. Also see IgA Nephropathy.

In more severe cases particularly in rapidly progressive glomerulonephritis, glucocorticoids and immunosuppressive agents (azathioprine, cyclophosphamide, mycophenolate mofetil, or other), plasmapheresis, or IV immunoglobulin may be used.

PrognosisTop

Prognosis is generally favorable, as most patients recover spontaneously. The primary cause of morbidity and mortality is due to renal consequences (~15% may develop long-term renal insufficiency).