The goals of emergency treatment of angioedema are to prevent spontaneous eruption, to maintain a patent airway if eruption does occur, and to stop progression of disease.  Laryngeal edema may occur rapidly. In these cases, a definitive airway such as an endotracheal tube should be established. If the airway cannot be effectively secured with an endotracheal tube, a surgical airway is indicated, usually in the form of an emergency cricothyrotomy.  Life-threatening airway obstruction (if swelling occurs in the throat) and anaphylactic reactions are possible complications. 
Treatment of angioedema includes histamine blockers (H1 and H2), steroids, and, in those with severe symptoms, epinephrine (intramuscular or subcutaneous). [4, 5]However, hereditary angioedema (HAE) is generally refractory to treatment with these drugs. Anabolic steroids (eg, danazol), a C1 esterase inhibitor, or a kallikrein inhibitor (ecallantide) may be used for the acute phase of an attack of HAE.
For more information on angioedema, see Acquired Angioedema, Hereditary Angioedema, and Pediatric Angioedema
Laryngeal edema from angioedema can progress rapidly and cause an immediate life-threatening emergency. In these cases, a definitive airway such as an endotracheal tube should be established.
Anaphylaxis is another possible complication. Treatment with epinephrine (EpiPen), histamine blockers, and steroids should also be initiated by emergency medical services (EMS) personnel, especially in cases of angioedema due to hypersensitivities.
Emergency Department Care
The initial goal of therapy is airway management. The most skilled person available must handle airway interventions because of the often massive degree of oral obstruction that is involved. A definitive airway must be established if edema is extensive or progressing.
Most patients with mild acute angioedema may be treated in the same way as those with an allergic reaction. Severe symptoms require steroids, H1 and H2 blockers, and subcutaneous epinephrine in addition to antihistamines. 
First-line antihistamine treatment
For antihistamine treatment, diphenhydramine, cetirizine, loratadine, or fexofenadine are the first-line drugs. However, hydroxyzine (10–100 mg daily at bedtime) can be tried when other H1 antihistamines are inadequate. 
Because 15% of H2 receptors are in the skin, use of H2 blockers is warranted to treat angioedema. The most commonly used agents are ranitidine or cimetidine. The H2 antagonists are highly selective and do not affect the H1 receptors; therefore, they must be used in conjunction with other therapies.
Doxepin (Adapin, Sinequan) is an excellent alternative to antihistamines because it has both H1 and H2 activity. Doxepin, a tricyclic antidepressant, blocks both types of histamine receptors and is a much more potent inhibitor of H1 receptors than either diphenhydramine or hydroxyzine; however, sedation is an even greater problem and may limit the usefulness of this drug.
Intravenous epinephrine (1:10,000) should be used in patients who demonstrate upper airway obstruction, acute respiratory failure, or shock.  Aerosolized epinephrine may also be used to help with obstructed airway.
The beta2-adrenergic agonist terbutaline (Brethaire, Brethine) has been shown to be more effective at controlling urticaria than placebo.  However, efficacy is low for urticaria and angioedema; therefore, it is seldom used for treatment of angioedema.