Allergy And Allergic Disease Flashcards
What is type 1 allergy
Ige mediated allergest against aeroallargens
How quick does type 1 allergy occur
Quickly
Hwo do you develop a type 1 allergy
- You are exposed to the allergen that the body recognises as foreign and dangerous
- Immune system produced an immune response to ti by producing ige
- When you are re-exposed you get an allergic response
Describe how an allergic reaction develops
- The antigen is in the body
- Ige stimulate the allergy cells
- FceR1 receptors on the mast cells or basophil cross link towith antigen/IGE
- Mast cells becomes activates and release substances to cause an allegic reaction
Which substances are released from mast cells
Histamines Prostaglandins Leukotrienes PAF Tryptase
What does the substances from mast cells cause
Vasodilation Icnreased vascular permeability Heart rate and contraction increased Glandular secretion Bronchosecretion
What is hayfever also known
Allergic rhinitis
What are the symptoms of hayfever
Nasal ithcing Runny nose Sneezing Allergic conjunctivitis Tears Eyes itching
Which allergen causes hayfever
Pollen
What are the tests that we can carry out in allergic rhinitis
Specifc ige test - to confirm allergy of history
Total ige: helps interpreted serum specifc ige
Skin prick test: more sensitive than serum specific ige
What is the management of allergic rhinitis
Step 1: allergen avoidance, nasal or oral antihistamine
Step 2: nasal steroid and nasal/oral antihistamine
Step 3: ipratropium bromide, increase antihistamine, LTRA
Step 4: confrim failed on maximal medical therapy, immunotherapy
What is allergic asthma
A phenotype of asthma where symptoms are worse on exposure to an allergen
What is allergic rhinitis a risk factor for
Allergic asthma
What is atopic dermatitis
Allergic skin disease and immunodeficiency and chronic inflammation
What is the cause of atopic dermatitis
There is often an underyling genetic defect in the barrier defence
What is the genetic defect called
Filaggrin (structural protein in the keratinocyte layer)
What is the treatment of atopic dermatitis
Avoid allergen
Prevent sratching
Prevent barrier defence breakdown
Treat the infection with antibiotic creams
Treat the chronic inflammation with steroids
What does disruption of the outer layer cause
Causes the allergen to penetrate the skin and come into contact with antigen presenting cells to generate a TH2 immune response
What is the difference between food allergery and food intolerance
Food intolerance is non ige mediated
What are the symptoms of food allergy
Itching
Swelling
Hives
Angioedema
What are the symptoms of food intolerance
Abdominal discomfot Bloating Vomiting Nausea Diarrhoea
What is the difference between the onset of allergy and food intolerance
Allergy occurs quick within 30 mins
Food intolerance lasts longer
What is the management of food allergy
Avoidance
Anti histamine
Adrenaline
What is the management of food intolerance
Avoidance
Re introduce slowly
No medication
