Life-threatening angioedema in systemic lupus erythematosus

Life-threatening angioedema involving the upper respiratory tract is an unc ommon manifestation in systemic lupus erythematosus (SLE). We report three patients in their late adolescence who had laryngeal oedema causing airway obstruction and requiring mechanical ventilation during active disease foll owing symptoms of a respiratory tract infection. All of them had major orga n involvement from lupus and none had a family history of hereditary angioe dema (HAE). The mechanisms of angioedema in SLE are heterogeneous. There ha s been little evidence so far of anti-Cl inhibitor (Cl INH) autoantibody in SLE patients with angioedema. These are the first three cases reported in the literature of life-threatening angioedema following respiratory tract i nfection in SLE.