Allergy and the Skin

Question 1

What are the functions of the immune system

Answer 1

Defence against external and internal antigens

Question 2

What are the consequences of the immune system

Answer 2

Intended destruction of antigen

Incidental collateral tissue damage

Question 3

Define hypersensitivity

Answer 3

Immune response that causes collateral damage to self
Exaggeration of normal immune mechanisms
Pathophysiological basis for allergy and autoimmunity etc

Question 4

When do allergic reactions occur

Answer 4

When a person’s immune system reacts to normally harmless substances in the environment

Question 5

What is the most common presentation of allergies

Answer 5

Urticaria

Question 6

What is a possible reason for an increase in allergy

Answer 6

Hygiene Hypothesis

Question 7

When does a Type 1 Allergic reaction occur

Answer 7

Immediate - minutes and up to 2 hours after exposure

Question 8

What routes of exposure can cause a type 1 allergic reaction

Answer 8

skin contact (latex, animal dander)
inhalation (pollen, dust mite)
ingestion (nuts, seafood)
injection (bee sting, medication)

Question 9

Define angioedema

Answer 9

localised swelling of subcutaneous tissue or mucous membranes

Question 10

What investigations can be done for an anaphylactic reaction

Answer 10

Specific IgE - specificity and sensitivity
Skin prick or prick-prick testing
Challenge test
Serum mast cell tryptase level (during anaphylaxis)

Question 11

What is the management for allergic reactions

Answer 11

Allergen avoidance
Prevent effects of mast cell activation (anti-histamines)
Anti-inflammatory agen (corticosteroids)
Adrenaline autoinjector (for anaphylaxis)
Immunotherapy
Medic Alert bracelet

Question 12

What dosage of adrenaline should be given for a) adults and b) children

Answer 12

300ug for adults

150ug for children

Question 13

Give 4 examples of non-allergic reaction

Answer 13

Coeliac’s (not mediated by IgE
Direct mast cell degranulation (morphine NSAIDs)
Metabolic (lactose intolerance)
Toxic (Scombroid fish toxin)

Question 14

Describe a type 4 allergic reaction

Answer 14

delayed hypersensitivity which is antigen specific and T cell mediated

Question 15

What can cause a type 4 allergic reaction

Answer 15

Allergic contact dermatitis

Question 16

What is the onset of a type 4 allergic reaction

Answer 16

After 24-48 hours

Question 17

What can cause axillary dermatitis

Answer 17

Fragrance in deodorants

Question 18

Where is ACD to garlic found on the body

Answer 18

the first 3 fingers on the left hand because thats where you would hold it when cutting

Question 19

What 3 factors could be contributing in any dermatitis

Answer 19

Endogenous
Allergic
Irritant

Question 20

What is Irritant contact dermatitis caused by

Answer 20

The skin coming into contact with agents that arade irritate and traumatise the skin directly

Question 21

What is the management for Irritant contact dermatitis

Answer 21

Allergen/ Irritant avoidance 
Emollients 
Topical steroids 
UV phototherapy
Immunouppressants