Angioedema

Question 1

Angioedema- causes:

Answer 1

Swelling of subcut and submucosa. Non pitting, non dependent

HISTAMINE mediated (70%) allergic process. Itchy, +- urticaria, adrenaline responsive.
- eg. most drug-related: NSAID, aspirin, opiates, Blactams, gliptins.
(+stings, food, latex etc.)

BRADYKININ mediated
More severe, more prolonged, no role for meds
- C1 ESTERASE INHIBITOR deficiency or dysfunction
—> Hereditary
or
—> Acquired (eg. Lymphoma, autoimmune)
- ACE-I / ARBS
- Trauma
- Cold
- Idiopathic

Question 2

Characteristics of ACE-I angioedema:
Mechanism
Risk Factors
Clinical
Management

Answer 2

Bradykinin- mediated
ie. persistent and resistant

Can occur any time on ACE-I
even months - years

RISK FACTORS
African
Female
Smoker
Older age

Typically tongue and mouth, upper airways

MANAGEMENT:
- Manage airway risk !!
- Discontinue ACE-I for life
- Will self-resolve
- May reoccur episodically in following months

NO ROLE for adrenaline/ antihistamine/ steroid in the non-histamine mediated angios. But give if not sure!

…C1 esterase inhibitor concentrate, Icatabant

Question 3

What features in history suggest HEREDITARY angioedema?

Answer 3

Eg. Hereditary C1 esterase inhibitor deficiency/dysfunction

Younger age of presentation (<30)
Family
History
Recurrent attacks (of angioedema, or abdo pain)
Attacks in setting of stressors: trauma, surgery, stress
Lack of response to allergy-based Tx

Question 4

Clinical approach to angioedema:
History
Exam
Management

Answer 4

DEMOGRAPHIC
-Kids (histamine)
-Young adult (<30- HAE)

HISTORY
-Triggers- eg. Food, insects (histamine) or stress/ trauma/ cold (bradykinin)
-Nature- eg. Itch/urticaria/ wheeze (histamine) or GI symptoms (bradykinin), airway involvement
- Meds: ACE, arb, aspirin, NSAID, opiate, gliptin, BLactam.
- Family history

EXAMINATION
Focus on ?airway oedema/ UAO signs
GI exam (can include imaging- oedema/ ascites)

MANAGEMENT
-Secure airway (may need fibre optic/ cric)

-If in any doubt, treat as per severe allergy/ anaphylaxis:
—> Adrenaline +- neb
—> Steroid
—> H1 and H2 Antihistamines

-If known bradykinin-mediated:
—> Stop trigger
—> FFP
—> C1 esterase inhibitor concentrate
—> Icatibant

On discharge:
-Refer to allergist
-Epipen/plan if histaminergic/ doubt
-C4 levels

Question 5

Can a patient with ACE-I angioedema be switched to an ARB?

Answer 5

Yes, possible.

10% or less risk of getting angioedema

Use alternative if possible. But if ARB has best benefit profile, likely to outweigh.