Anaphylaxis and Allergy

Question 1

What is atopy? What are the diseases which it presents as?

Answer 1

The ability to mount an IgE response to one or more common inhaled aeroallergen

Eczema

Asthma

Allergic rhinoconjunctivitis

Atopic dermatitis

Question 2

What is adrenaline dose in adults and children?

Answer 2

Adult: 0.5mg IM

Children: 0.01ml/kg (1:1000) IM Lateral thigh

Up to every 5 minutes, if not responding, consider infusion

Question 3

What the triggers of anaphylaxis?

Answer 3

Food: Peanuts, tree nuts, seafood, eggs, cow’s milk

Bites/stings: Bees, wasps, jumping ants Medications:

Betablockers, ab infusions, vaccines

Others: exercise, idiopathic, latex, hydatid

Question 4

What are clinical features of anaphylaxis? What is required for diagnosis?

Answer 4

Resp: Tongue swelling, angioedema, stridor, wheeze, cough, tightness/swelling in throat

Cardio: Cyanosis, Tachycardia, bradycardia, hypotension, cardiac arrest

Skin: Urticaria, angioedema, pruritis

Gastro: Vomiting, diarrhoea, nausea, abdo pain

At least one resp/cardio symptoms and at least one skin/gastro symptom

Except for non-food allergens where GIT involvement is considered anaphylaxis

Question 5

How do you manage anaphylaxis?

Answer 5

Lie patient supine (or on side if vomiting)

Administer IM adrenaline

Repeat dose if required

Call ambulance if in GP setting

Consider anti-histamines, corticosteroids

Observe for 4 hours

Consider IV access

Question 6

When do you admit a child after anaphylaxis?

Answer 6

Greater than one dose of adrenaline required

Fluid bolus given

Inadequate response to therapy

Long distance from medical services

Question 7

What are the long term treatment goals for a child whose had an anaphylaxis?

Answer 7

Action plan: Epipen (20 epipen 300ug)

Alert bracelet

Referral to allergy specialist

Ensure tight control of asthma

Question 8

What is the association between asthma and anaphylaxis?

Answer 8

Asthmatics are at increased risk of death from anaphylaxis

Question 9

How do you interpret positive skin prick tests?

Answer 9

• THe presence of specific IgE to an allergen is only one factor and should be correlated with history and/or trial of allergen avoidance/challenge

The negative predictive value is better than the positive predictive value

Question 10

What is the greatest predictor for the development of atopy?

Answer 10

Positive family history

• 40-60% likelihood of developing it if positive FHx in parents

Question 11

What do you advise patients before having a skin prick test?

Answer 11

Don’t take anti-histamines in the 5 days prior

Question 12

When is immunotherapy indicated?

Answer 12

Insert bite anaphylaxis

Intractable and debilitating pollen induced allergic rhinoconjunctivitis

Question 13

What is the “allergic march”?

Answer 13

Atopic dermatitis - usually by 6 months of life

Approximately 50% of these children then develop asthma in early childhood

Resolution of asthma in late childhood and development of allergic rhinitis which may be lifelong