Terminal Ileitis as a Feature of Henoch-Schönlein Purpura Masquerading as Crohn Disease in Adults.

Henoch-Schönlein purpura (HSP), more recently termed immunoglobulin A (IgA) vasculitis, is a systemic small-vessel vasculitis characterized by perivascular IgA deposition. This disease manifests clinically as palpable purpura, arthralgia, gastrointestinal symptoms, and renal dysfunction. Although ileitis can be seen in HSP, terminal ileitis is virtually pathognomonic for Crohn disease.