Vasculitis in children and adolescents: clinical presentation, etiopathogenesis, and treatment.

The childhood vasculitides are a group of diseases affecting small to large blood vessels. The two most common conditions are Henoch-Schönlein purpura (HSP) and Kawasaki disease (KD). HSP is diagnosed on the basis of typical clinical findings and is mostly a self-limiting disease. KD is the most common vasculitis in infants and the development of coronary artery aneurysms is the major complication. Early treatment with intravenous immunoglobulin and aspirin (acetylsalicylic acid) is required to minimize this risk. All other vasculitides are very rare in children and include anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis, polyarteritis nodosa and Takayasu disease. The etiology of all these vasculitic diseases is generally unknown and, therefore, no specific treatment is available. The more rare vasculitides are generally much more severe, often needing treatment with high doses of corticosteroids and immunosuppressant agents such as cyclophosphamide, azathioprine, and mycophenolate mofetil.