• Cryoglobulinemic vasculitis
o It is an immunocomplex vasculitis involving small vessels.
o The most common cause is HCV infection.
o Triad: Palpable purpura + arthritis + glomerulonephritis (most common MPGN type 1).
o Elevated liver enzymes and neuropathy (mononeuritis multiplex) may be seen.
o Most of the patients have RF positivity and hypocomplementemia.
o C4 level is lower than C3 level.
o Anti-HCV treatment is given primarily in HCV-associated cryoglobinemic vasculitis.
o Rituximab is used in relapsed or severe cases where antiviral drugs cannot be used.