Life-threatening angioedema in systemic lupus erythematosus.

Life-threatening angioedema involving the upper respiratory tract is an uncommon 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 following symptoms of a respiratory tract infection. All of them had major organ involvement from lupus and none had a family history of hereditary angioedema (HAE). The mechanisms of angioedema in SLE are heterogeneous. There has 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 infection in SLE.