Internal Medicine Nephrology Rheumatology

Henoch-Schonlein Purpura (IgA Vasculitis)

Henoch-Schonlein Purpura (IgA Vasculitis)
Purpura on the right lower leg of a child.

Introduction – Henoch-Schonlein Purpura

Henoch-Schönlein’s purpura (IgA vasculitis) is a small vessel vasculitis characterized by palpable purpura (secondary to cutaneous vasculitis) and glomerulonephritis. Possible etiologic factors that trigger the vasculitis include physical strain and nosocomial viral infections. Evidence for a connection between Henoch-Schönlein’s purpura and vaccinations did not find support in detailed literature analyses.

The disease is characterized by the presence of circulating IgA-containing immune complexes and IgA deposits in the involved organs (skin, gastrointestinal mucosa, kidneys). The disease often affects children and young adults.


Symptoms – Henoch-Schonlein Purpura

  • Skin and mucous membranes – Scattered palpable purpura in lower extremities and sometimes the facial area. Occasionally formation of vasculitis ulcers. Abdominal pain and vomiting due to erosions, bleeding in the stomach/intestinal mucosa.
     
  • Musculoskeletal – Arthralgia, non-erosive arthritis. Myalgias.
     
  • Kidneys – Kidney involvement occurs in 50% of cases. This is often expressed in the form of immune complex mediated mesangial proliferative glomerulonephritis. Deposits of IgA are present. Patients who exhibit crescent formation have a worse prognosis of renal function.

Diagnosis – Henoch-Schonlein Purpura

The diagnosis is made by finding palpable purpura with IgA deposits in the skin or in kidney biopsy. Hyperproduction of IgA occurs. Low levels of glycosylated IgA1 can often be detected in blood and kidney tissues.


Treatment and Prognosis

The prognosis is in most cases excellent, even without specific therapy. Most children recover spontaneously. In 20% of cases (mainly adults), chronic progressive glomerulonephritis develops. Risk factors for renal involvement are male sex, age >10 years, recurrent gastrointestinal disorders, joint pain, persistent purple rash, WBC <15×10 ^ 9 /L, Plt> 500×10 ^ 9 /L, low levels of C3 complement. Persistent proteinuria, hypertension and decreased GFR are unfavorable factors that determine treatment choice and duration. It should be treated with high-dose corticosteroids and possibly cytostatic drugs such as azathioprine (Imurel, Azathioprine). Resistant cases of IgA vasculitis can be successfully treated with rituximab (Mabthera).


Further Reading