IgA Vasculitis
IgA vasculitis affects small blood vessels and typically causes petechiae and purpura that is not accompanied by thrombocytopenia or coagulopathy. It was previously called Henoch Schonlein purpura. IgA vasculitis occurs most commonly in children between the ages of 3 and 15 years of age and is often preceded by upper respiratory tract infections. The majority of cases are self limited and require no specific therapy.
The classical triad in children includes:
- Palpable purpura without thrombocytopenia or coagulopathy
- Abdominal pain
- Arthritis or arthralgia
- Renal disease causing proteinuria and hematuria
In contrast to other vasculitides, most cases of IgA vasculitis begin with the onset of cutaneous lesions prior to other manifestations. Approximately two thirds of children develop gastrointestinal and renal involvement. Gastrointestinal involvement is usually characterized by colicky abdominal pain that often resembles an acute abdomen. IgA vasculitis most often involves the large joints of the legs, but any joint can be involved.
The diagnosis of IgA vasculitis is usually based on clinical manifestations. Serum IgA levels are elevated in 50 to 75% of cases, especially those with renal involvement. Onset of IgA vasculitis after a respiratory tract infection is often associated with decreased levels of complement C3 and C4. Platelet count and coagulation tests are normal. Tests for autoantibodies such as ANA and ANCA are negative. Skin biopsy reveals leukocytoclastic vasculitis involving postcapillary venules within the papillary dermis with predominant IgA deposition. It is important to note that IgA deposition may also be seen in leukocytoclastic vasculitis that is due to cryoglobulinemia or the use of certain medications, including tumor necrosis factor (TNF) alpha inhibitors.
Jennette JC et al. 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides. Arthritis Rheum 2013:65:1.
Piram M, Marh A. Epidemiology of immunoglobulin A vasculitis (Henoch-Schonlein): current state of knowledge. Curr Opin Rheumatol 2013;25:171.
