Immunology

Question 1

How often can we give adrenaline in anaphylaxis?

Answer 1

5mins

Question 2

When do we use skin patch testing?

Answer 2

Useful for contact dermatitis. Around 30-40 allergens are placed on the back. Irritants may also be tested for. The patches are removed 48 hours later with the results being read by a dermatologist after a further 48 hours

Question 3

How do we perform the skin prick test?

Answer 3

Drops of diluted allergen are placed on the skin after which the skin is pierced using a needle. A large number of allergens can be tested in one session. Normally includes a histamine (positive) and sterile water (negative) control. A wheal will typically develop if a patient has an allergy. Can be interpreted after 15 minutes

Useful for food allergies and also pollen

Question 4

What is the radioallergosorbent test?

Answer 4

Determines the amount of IgE that reacts specifically with suspected or known allergens, for example IgE to egg protein. Results are given in grades from 0 (negative) to 6 (strongly positive)

Useful for food allergies, inhaled allergens (e.g. Pollen) and wasp/bee venom

Blood tests may be used when skin prick tests are not suitable, for example if there is extensive eczema or if the patient is taking antihistamines

Question 5

What levels raise in anaphylaxis?

Answer 5

Serum tryptase

Question 6

Where do we inject IM adrenaline?

Answer 6

IM adrenaline should be injected in the anterolateral aspect of the middle third of the thigh

Question 7

How much adrenaline do you give in anaphylaxis in a child under 6?

Answer 7

6 months - 6 years adrenaline dose for anaphylaxis 150 mcg (0.15ml 1 in 1,000)

Question 8

Define refractory anaphylaxis

Answer 8

Refractory anaphylaxis is defined as respiratory and/or cardiovascular problems persisting despite 2 doses of IM adrenaline