Revision as of 20:38, 8 August 2015 by Rossdonaldson1 (talk | contribs) (Hereditary Angioedema)
Angioedema post lisinopril use


  • Angioedema is paroxysmal, nondemarcated swelling of dermal or submucosal layers of skin or mucosa
    • Swelling is asymmetric, nonpitting, and nonpruritic
  • 4 etiologies
    1. Congenital or acquired loss of C1 esterase inhibitor
    2. IgE–mediated type I allergic reaction
    3. ACEI adverse reaction (excessive bradykinin)
    4. Idiopathic
Angioedema of tongue

Hereditary angioedema


  • Due to C1 esterase inhibitor deficiency
    • Leads to unregulated activity of vasoactive mediators (bradykinin) associated with complement pathway
    • Autosomal dominant


  • Suspect in patients with history of recurrent peripheral angioedema and abdominal pain
    • 75% experience onset of symptoms before age 15yr
  • C4 level screens for HAE (suspect if low)
  • Decreased levels of C1 and C4 esterase inhibitors confirms diagnosis


  • Strongly consider definitive airway if voice change, hoarseness, stridor, dyspnea - arrange transfer to OR if not crashing
  • Epinephrine can produce some improvement in early acute attacks associated with anaphylaxis, however, HAE is bradykinin mediated and the role of steroids and H1/H2 blockers is limited
  • If available - C1 esterase inhibitors (Berinert 20u/kg IV), kallikrein/bradykinin inhibitors (ecallantide 30mg SQ), or bradykinin receptor antagonist (icantibant 30mg SQ)
  • FFP
    • Replaces the missing inhibitor protein
    • Not recommended in life-threatening laryngeal edema (some pts may become more edematous)
      • Instead, pt should undergo fiberoptic intubation w/ preparation for surgical airway

ACE Inhibitor-induced Angioedema


  • Incidence is highest within the first month; however, may occur at anytime
  • 40% present months to years after initial dose[1]
  • Incidence is 0.1-2.2% (more common in blacks)
  • Physiology more closely related to bradykinin-mediated pathway than IgE-mediated pathway, therefore current treatments may be insufficient


  • Airway management as above, consider awake fiberoptic intubation
  • Epinephrine 0.3mg IM q15-20min prn
  • Consider glucagon 1-5mg IV if pt on B-blockers and not responding to epi
  • Diphenhydramine 50mg IV OR cetirizine 10mg PO
  • Methylprednisolone 125mg IV
  • H2 blocker IV or PO

Differential Diagnosis

Acute allergic reaction


  • Consider discharge after 4-6 hrs obs if there is no airway edema and pt improves
  • 24 hrs obs if epi given
  • Ishoo Staging (based on retrospective study)[2]
    • Stage 1 - face/lip
      • 48% outpatient, 52% floor, 0% ICU or advanced airway
    • Stage 2 - soft palate
      • 60% outpt, 40% floor, 0 ICU or advanced airway
    • Stage 3 - tongue
      • 26% outpt, 67% ICU, 7% advanced airway
    • Stage 4 - larynx
      • 100% ICU, 24% advanced airway

See Also


  1. Winters ME, et al. Emergency department management of patients with ACE-inhibitor angioedema. JEM. 2013; 45(5):775–780.
  2. Ishoo E, et al. Predicting airway risk in angioedema: staging system based on presentation. Otolaryngol Head Neck Surg. 1999; 121(3):263-268.