A 22-year-old man presents to the emergency department with difficulty breathing. He has experienced similar symptoms before. Today, he was hit in the face with a football, followed by significant swelling of his lips and tongue. The patient speaks with a muffled voice. His temperature is 98.1°F (36.7°C), blood pressure is 120/83 mmHg, pulse is 80/min, respirations are 16/min, and oxygen saturation is 98% on room air. Physical exam reveals swollen lips and a protruding, enlarged tongue. His breath sounds are clear. He demonstrates no rash and his abdomen is soft and nontender. Which of the following is the most effective therapy for this patient?
Diphenhydramine
Dexamethasone
Fresh frozen plasma
Epinephrine
Fresh frozen plasma
This patient is presenting with recurrent episodes of significant swelling of his lips and tongue with minor trauma, which are concerning for hereditary angioedema. Fresh frozen plasma is the most effective therapy for hereditary angioedema of the options listed.

Angioedema is a potentially life-threatening condition that presents with severe edema of the gastrointestinal and respiratory tracts. It can be caused by antigens, medications, and trauma or may occur spontaneously. It often presents with notable edema of the lips and tongue and may threaten the airway. There are 3 subtypes. Hereditary and acquired angioedema occur secondary to a deficiency of C1-esterase inhibitor. As a result, the most effective therapy is to administer fresh frozen plasma which has C1-esterase inhibitor. On the other hand, drug-induced angioedema (often from angiotensin-converting enzyme inhibitors and angiotensin receptor blockers) does not respond well to C1-esterase inhibitor replacement and supportive therapy; discontinuing the offending agent is the mainstay of therapy. Other effective but costly treatments that can be used in hereditary angioedema include: icatibant, ecallantide, and C1 inhibitor.

Paige and Anderson note the management of hereditary angioedema. They review the different treatments and discuss C1-esterase inhibitor replacement. They recommend this treatment for acute episodes.

Incorrect Answers:
Answer A: Dexamethasone and other steroids can be given in acute allergic reactions and may reduce the recurrence of symptoms but are unlikely to be effective in angioedema, nor are they the most effective therapy. Steroids can take up to 4 hours to begin having any effect.

Answer B: Diphenhydramine is an antihistamine that could be given for anaphylaxis or urticaria and works immediately; however, it is not the mainstay of therapy for angioedema nor is it the most effective therapy. It is the mainstay of therapy for urticaria. It can also be given in anaphylaxis.

Answer C: Epinephrine is the treatment of choice for anaphylaxis which presents with urticaria, upper airway swelling, hypotension, nausea/vomiting, and wheezing. It is often given in angioedema but has limited efficacy when compared to fresh frozen plasma.

Answer E: Tranexamic acid is effective in treating angioedema and current evidence supports its use; however, the mainstay of therapy is still fresh frozen plasma. Tranexamic acid is also used in hemorrhagic shock to stop fibrinolysis and reduce bleeding.

Bullet Summary:
A possible treatment in hereditary or acquired angioedema is the administration of fresh frozen plasma to replace C1-esterase inhibitor.