Anaphylaxis

Question 1

What is Anaphylaxis?

Answer 1

A life-threatening medical emergency, caused by severe type I Hypersensitivity Reaction.

Question 2

Pathophysiology of Anaphylaxis.

Answer 2

IgE stimulates mast cells to rapidly release Histamine and other pro-inflammatory chemicals : MAST CELL DEGRANULATION.

Question 3

Clinical Presentation of Anaphylaxis (4 + 6).

Answer 3

Rapid-Onset of Allergic Symptoms :

1. Urticaria.
2. Itching.
3. Angio-Oedema (Swelling around Lips and Eyes).
4. Abdominal Pain.

EXTRA Symptoms :

1. Shortness of Breath.
2. Wheeze.
3. Stridor (Laryngeal Oedema).
4. Tachycardia.
5. Lightheadedness.
6. Collapse.

Question 4

Emergency Management of Anaphylaxis (7).

Answer 4

1. Escalate to Experienced Paediatrician.
2. A - Secure Airway.
3. B - Oxygen if Required and Salbutamol if Wheezing.
4. C - Provide IV Bolus of Fluids.
5. D - Lie flat to improve cerebral perfusion.
6. E - Look for flushing, urticaria and angio-oedema.
7. MEDICINE.

Question 5

Medical Emergency Management of Anaphylaxis (3).

Answer 5

1. IM Adrenaline - repeat after 5 minutes if required.
2. Antihistamine e.g. Chlorphenamine or Cetirizine.
3. Steroids e.g. IV Hydrocortisone.

Question 6

Short-Term Management of Anaphylaxis (2).

Answer 6

1. Period of Assessment and Observation - Biphasic Reaction.

2. Confirm anaphylaxis - measure Serum Mast Cell Tryptase within 6 hours.

Question 7

What is a Biphasic Reaction?

Answer 7

A 2nd Anaphylactic reaction after successful treatment of the 1st.

Question 8

Long-Term Management of Anaphylaxis (3).

Answer 8

1. Education - Avoidance and Recognition.
2. Basic Life Support.
3. Specialist Allergy Referral for all new diagnoses.

Question 9

Indications of an Adrenalin Auto-Injector (Epipen) (2D).

Answer 9

1. All kids with Anaphylactic Reactions.
2. Kids with Generalised Allergic Reaction +
   A. Asthma + Inhaled Steroids.
   B. Poor Access to Treatment e.g. Rural.
   C. Nut/Insect Sting Allergy.
   D. Significant Co-Morbidities.

Question 10

Doses of Adrenaline in Anaphylaxis (4).

Answer 10

1. <6 Months : 100-150mcg.
2. 6 Months - 6 Years : 150mcg.
3. 6 Years - 12 Years : 300mcg.
4. Adults + Kids > 12 Years : 500mcg.

Question 11

How is Adrenaline Injected? (3)

Answer 11

1. ASAP.
2. Every 5 minutes if necessary.
3. Site : Anterolateral Aspect of Middle Third of Thigh.

Question 12

What is Refractory Anaphylaxis?

Answer 12

Respiratory and/or Cardiovascular problems that persist despite 2 doses of IM Adrenaline.

Question 13

Management of Refractory Anaphylaxis (2).

Answer 13

1. IV Fluids - Shock.

2. Escalate - IV Adrenaline Infusion.

Question 14

Discharge of Anaphylaxis (3).

Answer 14

1. Fast-Track (After 2 Hours) if OK.
2. 6 Hours if 2 doses of Adrenaline or Previous Biphasic Reaction.
3. 12 Hours if Worse.