What is the treatment for angioedema?

Treatment of Angioedema

The treatment of angioedema depends on its underlying cause, with bradykinin-mediated angioedema (hereditary, acquired C1INH deficiency, or ACE inhibitor-induced) requiring specific targeted therapies, while histamine-mediated angioedema responds to standard treatments with antihistamines, corticosteroids, and epinephrine. 1, 2

Classification of Angioedema Types

Histamine-Mediated Angioedema

• Most common form (allergic or idiopathic)
• Often associated with urticaria (in ~50% of cases)
• Common triggers: foods, medications, insect stings 3

Bradykinin-Mediated Angioedema

• Hereditary angioedema (HAE)
• Acquired C1 inhibitor deficiency
• ACE inhibitor-associated angioedema 1

Treatment Approach Based on Angioedema Type

Histamine-Mediated Angioedema Treatment

1. First-line treatment:

   • Epinephrine 0.3-0.5 mL of 1:1000 solution IM for severe cases 2
   • IV methylprednisolone 125 mg
   • IV diphenhydramine 50 mg
   • IV ranitidine 50 mg or famotidine 20 mg 2

2. Supportive care:

   • Airway evaluation and management
   • Aggressive hydration
   • Pain control as needed 2

Bradykinin-Mediated Angioedema Treatment

Hereditary Angioedema (HAE) Acute Attack Treatment

1. First-line options:

   • Plasma-derived C1 inhibitor concentrate (most effective when given early) 2
   • Icatibant (bradykinin B2 receptor antagonist) - 30 mg subcutaneously in the abdominal area 4
   • Ecallantide (plasma kallikrein inhibitor) 2

2. Important note: Standard treatments for allergic angioedema (epinephrine, corticosteroids, antihistamines) are NOT effective for HAE attacks 1, 5, 6

3. Dosing for icatibant:

   • 30 mg subcutaneously in the abdominal area
   • Additional 30 mg doses may be administered at intervals of at least 6 hours if needed
   • Maximum of 3 injections in 24 hours 4

ACE Inhibitor-Associated Angioedema

1. Primary management: Discontinuation of the ACE inhibitor (or ARB) 1
2. Note: There may be a significant time lag between discontinuation and resolution of symptoms 1
3. Treatment options: Icatibant and fresh frozen plasma have been described as effective, though no controlled studies have been reported 1

Acquired C1INH Deficiency

1. Treatment options similar to HAE:
   • C1INH replacement therapy (may be less effective if high levels of C1INH autoantibodies present)
   • Ecallantide and icatibant have been reported effective 1
2. Long-term prophylaxis:
   • Antifibrinolytic drugs often more effective than in HAE
   • Androgens can be used 1

Airway Management

• Critical priority: Evaluate for signs of impending airway closure (change in voice, difficulty swallowing/breathing)
• Consider early elective intubation if signs of airway compromise develop
• Awake fiberoptic intubation is optimal if intubation needed
• All patients with oropharyngeal or laryngeal angioedema should be observed in a facility capable of emergency airway management 2
• Emergency cricothyroidotomy may be necessary in life-threatening airway obstruction 7

Long-Term Prophylaxis for Recurrent Angioedema

HAE Prophylaxis Options

1. Plasma-derived C1INH replacement
2. Lanadelumab
3. Attenuated androgens
4. Tranexamic acid (15-25 mg/kg 2-3 times daily) as second-line option 2

Special Considerations

• Pregnancy: Androgens are contraindicated; plasma-derived C1INH is preferred 2
• Estrogen: Avoid estrogen-containing contraceptives in women with HAE 1
• ACE inhibitors: Should be avoided in patients with any form of bradykinin-mediated angioedema 7

Common Pitfalls in Angioedema Management

1. Misdiagnosis: Treating bradykinin-mediated angioedema with antihistamines and corticosteroids, which are ineffective 5, 6
2. Delayed treatment: Especially dangerous for laryngeal attacks which can be life-threatening 5
3. Medication errors: Continuing ACE inhibitors or prescribing estrogen-containing medications in susceptible patients 2, 7
4. Inadequate monitoring: Failing to observe patients with oropharyngeal or laryngeal involvement 2

Remember that proper identification of the angioedema type is crucial for effective treatment, as the standard treatments for allergic angioedema are ineffective for bradykinin-mediated forms, which require specific targeted therapies.