Angioedema is the diffuse edematous swelling of the soft tissues that most commonly involves the submucosal and subcutaneous connective tissues. It can also affect the connective tissues of the respiratory and gastrointestinal tract. The most common pathogenesis is the degranulation of mast cells, leading to histamine release and increased vascular permeability. The immunoglobulin E (IgE)-mediated hypersensitivity reactions are triggered by foods, preservatives such as sodium benzoate used in peanut butter, dust, drugs like angiotensin-converting enzyme inhibitors (ACE) like captopril, enalapril, lisinopril and pollens, and contact allergies started by prolonged contact with dental rubber dams and cosmetics. Hereditary factors such as quantitative reduction of C1 esterase inhibitor (C1-INH) deficiency and dysfunctional C1 esterase inhibitor (C1-INH) are also postulated in its etiopathogenesis. In addition, lymphoproliferative disorders, bacterial or viral infections, lupus erythematosus, and minor trauma from dental procedures may precipitate an angioedema attack.