There has been a paucity of trials enrolling young children to evaluate the efficacy of hereditary angioedema therapies However, international guidelines recommend treating children with acute attacks given the risk of morbidity and available safety data Human C1-esterase inhibitor concentrate has approval by the FDA for routine prophylaxis in adolescents and adults (Cinryze, 1,000 units every to days) and in the management of acute attacks C1-esterase inhibitor concentrate can be administered parenterally (20 units per kg up to 1,000 units [Berinert], or 50 units per kg up to 4,200 units of the recombinant product [Ruconest]) to patients presenting with laryngeal edema or symptoms of an acute abdominal process This treatment generally begins to alleviate symptoms within 30 to 60 minutes; however, repeat doses may be required Hospitalization is often necessary in patients with upper airway involvement or refractory abdominal pain With appropriate training, patients can be prescribed C1-esterase inhibitor concentrate (Berinert) for home administration provided epinephrine is available in case of hypersensitivity reactions Patients who self-administer C1-esterase inhibitor concentrate for laryngeal attacks are advised to seek immediate medical treatment due to the risk of airway obstruction Other therapies include the plasma kallikrein inhibitor ecallantide (Kalbitor, 30 mg as three 10-mg subcutaneous injections for patients age ≥12 years) and the bradykinin B2 -receptor antagonist icatibant (Firazyr, 30 mg subcutaneously, patients ≥18 years) SERUM SICKNESS CLINICAL PEARLS AND PITFALLS True serum sickness reactions are uncommon secondary to decreased use of medications derived from heterologous serum Serum sickness–like reactions are characterized by fever, urticarial or vasculitic-appearing rash, and arthralgias Reactions are most common in young children after antibiotic or other medication exposures during the preceding to 14 days Most children with serum sickness–like reactions can be managed as outpatients with supportive care (NSAIDs, antihistamines, and oral corticosteroids for severe/protracted cases) Current Evidence