Angioedema
Angioedema
Definition: self-limited, asymmetric, localized, non-pitting swelling
Background
- 15% of population
- 50% with urticaria
- Common sites: perioribtal, lips, tongue, extremity, bowel wall
- Main cause of death: Laryngeal edema (25-40% mortality if present)
Syndromes and Specific Treatments
Idiopathic Angioedema
- 38% of patients with angioedema
Allergic or IgE Mediated Angioedema
- Type I hypersensitivity reaction
- Commonly from food or medications
- Tx: allergen avoidance, antihistamine, H2 blockers, glucocorticoid, epinephrine for laryngeal edema
Hereditary Angioedema
- C1q esterase inhibitor deficiency
- Triggers: trauma (especially dental trauma), anxiety, menstruation, infection, exercise, alcohol consumption, stress
- Prophylaxis tx: danazol better than tranexamic acid and aminocaproic acid
- Acute tx: FFP, C1 INH, icatibant, and ecallantide can all be used
- Usual IgE-mediated treatment regimen ineffective except epinephrine for laryngeal edema
ACE Inhibitor Angioedema
- 0.3-0.7% of those taking ACE-I's
- From elevated levels of bradykinin
- Highest incidence during 1st month of starting medication, but can occur years after
- 5x more common in African-Americans compared to Caucasians
- Controversial whether patient can take ARBs (doesn’t cause elevated bradykinin) as well – some with angioedema.
- Tx: Discontinue medication and supportive care
- Usual IgE-mediated treatment regimen ineffective except epinephrine for laryngeal edema
Treatment philosophy:
- Low threshold to protect airway by intubation
- If initial exam does not trigger an intubation frequent re-evaluations should be made as a patients clinical picture can change rapidly
- Once a decision for intubation has been made make sure you are prepared to perform an emergent cricothyroidotomy if necessary and consult Anesthesia or ENT. Also consider performing Fiberoptic nasopharyngoscopy to evaluate the patients airway and if needed as a primary airway technique. Finally consider NOT paralyzing these patients, and possibly using Ketamine as your induction agent
- Fiberoptic nasopharyngoscopy: consider performing on all patients with voice change to look for largnyeal edema
- Pearl: Be sure to prescribe patients Epi-pen if discharged home
Admission guidelines for angioedema
(Ishoo et al., Head Neck Surg, 1999)
- 93 episodes in 80 patients (1985-95) with no deaths
- 9.7% cases required intubation/tracheostomy
- Causes: 39% from ACE-I
- Disposition: 25% outpt, 23% floor, 53% ICU
- ICU admissions correlated with voice change, hoarseness, dyspnea, rash
- Airway intervention correlated with voice change, hoarseness, dyspnea, stridor
Proposed staging system:
- Stage I: Facial rash, facial edema, lip edema - outpatient
- Stage II: Soft palate edema – outpatient or floor
- Stage III: Lingual edema --> ICU (7% required airway intervention)
- Stage IV: Laryngeal edema –> ICU (24% required airway intervention)
References
- Ishoo E et al. Predicting airway risk in angioedema: Staging system based on presentation. Otolaryngol Head Neck Surg 1999; 121:263-8. [[PubMed] PubMed]
- Temino VM, Peebles RS. Spectrum and Treatment of Angioedema. Am J Med 2008; 121: 282-6(https://www.ncbi.nlm.nih.gov/pubmed/?term=18374684)
- Guyer AC, Banerji A. ACE inhibitor-induced angioedema. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA. (Accessed on June 4, 2015.) [Source]
- Shenvi C, Serrano K. New Treatments for Angioedema. Emergency Physicians Monthly. Sep 2016. [Source]