ENT - Allergy Flashcards
Name reasons for why allergies are becoming increasingly common?
- Children not developing immunity as kept too clean
- Climate change
- Eating more processed food
- Sedentary lifestyles and obesity
What happens to IgE in allergic reactions?
Specific IgE made for allergens and their levels are raised during allergic reactions
Name risk factors for developing allergies
- Host factors
- Environmental factors
- Occupational factors
What are host factors that increase risk of developing allergies?
- Hereditary
- Race
- Age
What are environmental factors that increase risk of developing allergies?
Alterations in exposure to infectious diseases during early childhood, environmental pollution, allergen levels and dietary changes
What are occupational causes that increase the risk of developing allergies?
Flour, latex, wood dust
Name allergies of different parts of the body?
- Skin: urticaria / angioedema
- Upper respiratory: rhinitis
- Lower respiratory: asthma
- Systemic: anaphylaxis
What changes in the body occur in systemic allergies-allergen reactions?
Whole body swells due to massive allergic reaction – allergen antibody reaction to release histamines, prostaglandins, leukatrine etc causing loads of oedema which closes airways causing death
Name risk factors for allergic rhinitis?
- Atopy
- Family history
- Environmental factors - exposure to infectious diseases during early childhood
- Environmental pollution
- Allergen levels
- Dietary changes
Name intermediate symptoms of allergic rhinitis
- Sneezing
- Itch
- Nasal blockage
- Rhinorrhoea
Name the late symptoms of allergic rhinitis
- Chronic obstruction
- Hyposmia
- Hyperreactivity
Define allergy
Hypersensitive disorder of the immune system
Are allergies congenital?
No - allergic reactions occur to normally harmless environmental substances known as allergens, these reactions are acquired as child develops sensitivity
Define allergen
Antigen that causes allergic reactions - usually proteins
What type of reaction occurs in allergic reactions?
Type 1 - Immediate hypersensitivity reaction
Describes what happens in type 1 immediate hypersensitivity reaction
- Sensitisation: plasma cells produce IgE which binds to mast cells
- Re-exposure: Mast cells degranulate which release histamine, leukotrienes, prostaglandins and chemotactic factors
What is an allergic reaction?
It’s an exaggerated or inappropriate immune reaction and causes damage to the host
What do mast cell release after degranulation?
- Histamine
- Leukotrienes
- Prostaglandins
- Chemotactic agents
What is the effect of mast cell degranulation?
- Vasodilation
- Vascular permeability
- Smooth muscle contraction
- Leukocyte infiltration
What occurs during the acute response of an allergic reaction?
- Exposure of allergen
- Ag+ specific IgE
- Degranulation with release of histamine, cytokines, interleukins, leukotrienes and prostaglandins from their granules causing systemic effects, such as vasodilation, mucous secretion, nerve stimulation and smooth muscle contraction
What occurs during the late phase response of an allergic reaction?
- 2-4hrs
- This is due to the migration of other leukocytes such neutrophils, lymphocytes, eosinophils and macrophages to the initial site
What are systemic effects occurs during inflammatory response?
- Sneezing
- Coughing
- Wheezing
- Runny nose
- Weepy eyes
- Itchiness
What is allergic rhinitis?
Allergic inflammation of the nasal airways
What triggers allergic rhinitis?
Occurs when allergen is inhaled by an individual with a sensitised immune system
Describe allergic rhinitis classification for intermittent AR?
Symptoms
• < 4days per weeks
• or < 4 consecutive weeks
Describe allergic rhinitis classification for persistent AR?
Symptoms
• > 4 days/weeks
• and > 4 days consecutive weeks
Describe allergic rhinitis classification for mild AR?
- Normal sleep
- No impairment of activities / work / school
- Symptoms present but not troublesome
Describe allergic rhinitis classification for mild AR?
- Sleep disturbance
- Impairment of activities / work / school
- Troublesome symptoms
What two tests are used to diagnose allergic rhinitis?
- Skin tests
* RAST
What is RAST test?
Detects presence and levels of allergen-specific IgE
Name three other tests for allergy investigations
- Total serum IgE
- Nasal allergen challenge
- Nasal cytology
When is a total serum IgE test carried out?
If patient is highly atopic as would require a different treatment than anti-histamines and avoiding allergens
What are three treatment options for allergies?
- Allergen avoidance
- Pharmacotherapy
- Immunotherapy
Name six different types of pharmacotherapy
- Topical Intranasal steroids
- Systemic Steroids
- Antihistamines
- Sodium Cromoglycate
- Allergen Immunotherapy
- Anti-IgE
What is immunotherapy?
Give tiny bits of allergen to patient so that the body producing IgE against allergen so body stops recognising allergen in foreign body – in controlled environment over 3 days developing immune tolerance to allergen by repeated exposure
