Can cryoglobulins produce a vasculitis?

Yes. Some authorities consider cryoglobulinemic leukocytoclastic vasculitis to be a distinct subset of leukcytoclastic vasculitis, and it is often discussed separately. Cryoglobulinemic vasculitis is most commonly associated with type II cryoglobulins (monoclonal immunoglobulins, usually IgM, with rheumatoid factor binding activity to the Fc portion of polyclonal IgG) and type III cryoglobulins (mixed polyclonal immunoglobulins that usually bind to IgG). Type I immunoglobulins (monoclonal immunoglobulin, most commonly IgM) are more likely to present as occlusive infarctive lesions without an associated infiltrate, although rare cases of vasculitis have been reported. Hepatitis B and C are emerging as major causes of mixed cryoglobulinemia. Clinically, patients with cryoglobulinemic leukocytoclastic vasculitis resemble those having classic adult leukocytoclastic vasculitis, except that the lesions are more commonly associated with cold exposure and are more commonly confined to acral areas where the body temperature is lower.