Angioedema
Background
- 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
- 4. Idiopathic
Hereditary Angioedema
Background
- Due to C1 esterase inhibitor deficiency
- Leads to unregulated activity of vasoactive mediators (bradykinin) associated with complement pathway
- Autosomal dominant
Diagnosis
- 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
Treatment
- 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
Background
- Incidence is highest within the first month; however, may occur at anytime
- 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
Treatment
- Epinephrine 0.3mg IM q15-20min prn
- Diphenhydramine 50mg IV OR cetirizine 10mg PO
- Methylprednisolone 125mg IV
- Awake fiberoptic intubation
Disposition
- 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)
- 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
- Stage 1 - face/lip
See Also
Source
Tintinalli