Although more than 45 years have passed since hypocomplementemic urticarial vasculitis (HUVS) was first described by McDuffie and colleagues at the Mayo clinic, data on epidemiology, disease outcomes, prognosis and clinical features are scarce. Recently, we published the first epidemiological study of HUVS including data on incidence, prevalence, disease outcomes, prognosis and clinical features using data from two separate Swedish regions during a period of 16 years. The estimation of incidence and prevalence rates indicates that HUVS is rare but not always benign. Renal and lung manifestations were severe in some cases, highlighting the need for careful screening and monitoring of this potentially serious condition. It is reasonable to suspect HUVS in patients with unexplained systemic inflammation combined with >6 months of urticaria. Special attention should be paid to patients with recent-onset dyspnea and proteinuria.