Condition	Characteristics
Essential mixed cryoglobulinemia	Palpable purpura, LCV, neuropathy, arthritis, renal involvement, hypocomplementemia, cryoglobulins
Henoch-Schönlein purpura	Palpable purpura, LCV with immunoglobulin A deposits in blood vessel walls, arthritis or arthralgia, abdominal pain, renal involvement
Idiopathic hypersensitivity vasculitis	Palpable purpura, LCV, elevated erythrocyte sedimentation rate, no offending medications or underlying cause detected despite extensive work-up
Schamberg disease	Asymptomatic, nonpalpable, brownish, macular eruption
Thrombotic thrombocytopenic purpura	Thrombocytopenia, schistocytes on peripheral smear, renal insufficiency, may cause neurologic symptoms