ABSTRACTIntroduction: Hereditary angioedema due to C1 inhibitor (C1-INH) deficiency (C1-INH-HAE) is a rare disorder, characterized by episodes of cutaneous and/or mucosal edema with unpredictable location and clinical severity. It belongs to the bradykinin-mediated angioedemas requiring specific treatment. Excessive bradykinin release, the culprit behind the onset of symptoms, can be prevented by the supplementation of deficient proteins or by the inhibition of kallikrein, as well as by blocking the effects of bradykinin on its receptor with the administration of a bradykinin B2 receptor antagonist.Areas covered: Human plasma-derived C1-INH has been used for decades to replenish the deficient protein and lately, recombinant human C1-INH (rhC1-INH), conestat alfa (Ruconest) has become available for this purpose. Three randomized, double-blind, placebo-controlled trials, one open label, and three open-label extension studies have demonstrated the safety and efficacy of rhC1-INH administered for the management of edematous episodes occurring in adolescent patients, or adult patients with C1-INH-HAE regardless of the location of edema and with repeated dosing. Moreover, a pilot study has shown rhC1-INH promising also for the prophylaxis of edematous attacks.Expert opinion: The introduction of rhC1-INH has expanded the therapeutic options available for the management of C1-INH-HAE, and advanced the individualized therapy for patients with this disease.