Angioedema

Angioedema Angioedema is Swelling of the deep dermis, subcutaneous or submucosal tissue, or mucous membranes as a result of vascular leakage. Usually nonpitting and nonpruritic. Associated with pain, Involved skin often shows no change in color.Most commonly observed affecting the lips and eyes (periorbital).Other commonly involved areas may include the face, hands, feet, and genitalia. Types of Angioedema: 1 . Allergic Angioedema: o Type 1 hypersensitivity reaction. o IgE/histamine-mediated angioedema. o Often associated with urticaria. o Typically occurs after 30 min to 2 hours after exposure to allergen Food , Drugs , Insect bite. 2 . Pseudo-allergic Angioedema: o Non-IgE Mediated. o Caused by a non-allergic or non-immunologic reaction. o Presentation is very similar to those of allergic angioedema. o Typical examples are angioedema induced by NSAIDs (Aspirin). 3 . Hereditary Angioedema: o Autosomal dominant disorder.o Bradykinin-mediated Angioedema.o Non-Allergic Angioedema (Non-IgE/histamine Mediated).o Not associated with urticaria.o Most patients report a family history of disease.o Caused by abnormality in C1 -INH and C4: Lead to increase in Bradykinin level.o Types of Hereditary Angioedema:TYPE 1 : C1-INH Deficiency (Most common).TYPE 2 : C1-INH DysfunctionTYPE 3 : Normal C1-INH but Dysfunction C1 Esterase. 4 . Acquired Angioedema: o Bradykinin-mediated Angioedema. o Non-Allergic Angioedema (Non-IgE/histamine Mediated). o Not associated with urticaria. o Caused by accelerated consumption of C1-INH or the production of autoantibodies to C1-INH. Lead to increase in Bradykinin level. o Onset is usually in the fourth decade of life. o Associated with autoimmune diseases and lymphoproliferative disorders. 5 . ACE inhibitor induced Angioedema: o Bradykinin-mediated Angioedema. o Non-Allergic Angioedema (Non-IgE/histamine Mediated). o Not associated with urticaria. o Caused by ACE inhibitors (Captopril): Anti-Hypertension medications. Inhibit conversion of Angiotensin-I to Angiotensin-II. Inhibit break down of Bradykinin. Lead to increase in Bradykinin level. 6 . Physically induced Angioedema: o Non-Allergic Angioedema (Non-IgE/histamine Mediated). o Caused by physical agents, such as cold, heat pressure, vibration, and ultraviolet radiation. 7 . Idiopathic Angioedema: o Exact mechanism is unclear. o Most common cause of AE (40%). Important clinical information should include the following: o Onset of angioedema:Acute ( 6 weeks). o Associated urticaria:Allergic angioedema. o History of recent use of new food or medicine:Allergic angioedema. o History of recent use of NSAID:Pseudo-allergic angioedema. o History of recent use of ACE-inhibitors:ACE inhibitors-induced angioedema. o Family history of angioedema:Hereditary angioedema. o History of Recurrent angioedema:Hereditary angioedema.ACE inhibitors-induced angioedema. Clinical picture: o Oropharyngeal Angioedema: Involving lips, tongue or uvula. o Laryngeal Angioedema: Stridor and airway obstruction. o Peripheral Angioedema: Involving feet and hands. o Abdominal Angioedema: Involving intestinal mucosa. Lead to abdominal pain. o Urogenital Angioedema: Involving scrotum Approach for Angioedema: Most cases can be managed well with outpatient treatment alone Inpatient care for angioedema is usually not necessary when timely treatment is administered. Indications of ICU admission for observation +/- early intubation: 1 . Laryngeal involvement (Stridor). 2 . Tongue edema. 3 . Multiple site involvement. Angioedema with Urticaria: Occurs due to Allergic IgE-Mediated angioedema. Acute treatment: o Anti-Histamine (1st line): H1 Blocker: Diphenhydramine 50mg IV. H2 Blocker: Ranitidine IV. o Steroid: Indicated for moderate-to-severe cases. Hydrocortisone 200mg IV. Methylprednisolone 40-60 mg IV. Prednisolone 40-60 mg OD x 5 days. o Epinephrine (1 :1000): 0.5 mg IM Q5 minutes PRN. Indicated in patients with impeding airway obstruction (involvement of larynx or tongue). Chronic treatment: o Anti-Histamine (1st line): Daily dose of non-sedating anti-histamine. If uncontrolled symptoms: Consider doubling the dose of antihistamine and/or adding a second antihistamine. Consider further increase in dose of antihistamine up to 4 times the recommended dose. Doxepin (Tricyclic antidepressant) has potent H1-blocking activity and has been used off label to treat recalcitrant angioedema. If infrequent symptoms: Consider PRN dose of antihistamine. o Steroid: Indicated for more severe symptoms not controlled with antihistamine alone. Prednisolone 40-60 mg OD x 5 days. o Instructions: ACE inhibitor should be stopped and avoided in future, even if the patient is not taking it. Angiotensin 2 Blocker (Losartan), can be used safely. Epinephrine autoinjector should be considered if there is a history of significant angioedema affecting the upper airway. Angioedema without Urticaria: Occurs due to Non-Allergic IgE-Mediated angioedema. o Hereditary angioedema. o ACE inhibitors-induced angioedema. Labs should be requested to exclude C1-INH abnormalities: o C4 Level o C1-INH level o C1-INH function Acute treatment: o C1 -INH concentrate: Infusion of C1-INH 20 U/kg. Shorten the duration of acute attack. Relief of symptoms within 1 hour of administration. o Fresh Frozen Plasma (FFP): 2 units of FFP, which contains C1-INH, has been shown to be helpful in certain patients. However, FFP also contains substrates that may worsen angioedema attacks. If this treatment is used, be ready to intubate or perform a tracheostomy, if necessary. o Ecallantide: Potent, selective, reversible inhibitor of plasma kallikrein. Suppresses bradykinin generation. FDA approved for treatment of acute HAE attacks. o Icatibant: Bradykinin B2 receptor antagonist. FDA approved for treatment of acute HAE attacks.

Angioedema

Types of Angioedema:

1 . Allergic Angioedema:

2 . Pseudo-allergic Angioedema:

3 . Hereditary Angioedema:

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