Background: Recurrent angioedema may affect the skin or, less commonly, the tongue, gastrointestinal tract, and larynx. Angioedema is a clinical sign that can be produced by a variety of diseases. Asphyxiation due to edematous obstruction of the upper airway is rare, but, for the affected patients, it is a permanent risk.
Methods: Review of the literature based on a selective search and the authors' decades of experience treating patients with angioedema in a dedicated ambulatory care unit.
Results: Hereditary angioedema due to C1 esterase inhibitor deficiency has been intensively studied, and nearly all steps in its pathogenesis are known, from the causative gene defect all the way to the clinical presentation of angioedema. Bradykinin is the main mediator in this pathway. New treatment options (icatibant; C1-inhibitor concentrate for self-administration and long-term treatment) have helped patients considerably. In recent years, a new type of hereditary angioedema has been described, resulting not from a lack of C1 inhibitor, but rather from mutations of coagulation factor XII or other, as yet unidentified genetic abnormalities. There are major differences in the pharmacological treatment of the different diseases that cause angioedema. In an emergency, when severe upper airway obstruction can be life-threatening, immediate treatment is needed to keep the upper airway open.
Conclusion: In patients with recurrent angioedema, the diagnostic classification of the underlying disorder as a particular type of hereditary or acquired angioedema is a prerequisite for appropriate treatment.