The clinical, serologic, and immunopathologic heterogeneity of cutaneous leukocytoclastic angiitis.

Histologically identical cutaneous leukocytoclastic angiitis occurs in patients with different serologic markers for vasculitis. When categorized on the basis of serologic analysis for antineutrophil cytoplasmic autoantibodies and IgA fibronectin aggregates, categories of leukocytoclastic angiitis have many overlapping features; however, there are distinctive clinical and immunopathologic trends among the categories. When both serologic tests are negative, there is a low probability that systemic vasculitis is present. The presence of either serologic marker indicates a strong probability for the presence of extracutaneous vasculitis and/or glomerulonephritis.