3. Hypocomplementemic urticarial vasculitis, cryoglobulinemic vasculitis, and other known secondary skin vasculitides such as those secondary to systemic lupus erythematosus, Sjögren syndrome, another auto-immune condition, a cancer, a hematological disorder, an ongoing active infection, or an ongoing medication. Investigators should consider such underlying diagnoses and perform and interpret appropriate laboratory work-up where indicated based on clinical presentation.