ENT - Allergy Flashcards
What is the incidence of asthma in the UK?
10%
Where is asthma most common?
Developed countries
Treatment of allergy-related disorders costs how much p/a in Scotland?
£130 million
Allergy/hypersensitivity is mediated by what?
IgE
What are the risk factors for allergy related disorders/
Heredity, race, age
Environmental exposure
Occupational
What environmental factors increase the risk of allergic disease?
Infectious diseases in childhood
Pollution
Diet
How many asthma patients have atopy?
4/5
Risk factors for allergic rhinitis?
Atopy Family history Childhood infectious disease Pollution Allergen levels
Allergic rhinitis often presents with what?
Asthma
Atopic dermatitis
What are the immediate symptoms of allergic rhinitis?
Sneezing
Itch
Nasal blockage
Rhinorrhoea
Why does allergic rhinitis cause watering eyes?
Swelling in nasal end of naso-lacrimal duct causing blockage
What are the late symptoms of allergic rhinitis?
Chronic obstruction
Hyposmia
Hyperreactivity
How is allergy defined?
Hypersensitivity disorder of the immune system
What is an allergic reaction?
Type 1 Immediate Hypersensitivity reaction
What is the pathological process leading to allergy?
Sensitization
(plasma cells to IgE, bind to mast cells)
Re-exposure
(Mast cells degranulate, release histamines, prostaglandins, leukotrienes, chemotactic factors)
What factors are released in mast cell degranulation?
Histamines,
Postaglandins,
Leukotrienes,
Chemotactic factors
How do the factors released in mast cell degranulation effect the body?
Vasodilation
Vascular permeability inc.
Smooth muscle contraction
Leukocyte infiltration
What leukocytes are associated with allergy?
Eosinophils
What is the late phase of allergic response?
2-4hrs
Migration of leukocytes to initial site
What is allergic rhinitis?
Allergic inflammation of the nasal airways
What are the ARIA classifications of allergy symptoms?
Intermittent or Persistent
Mild or Moderate Severe
What is intermittent allergy?
<4 days per week
OR <4 consecutive weeks
What is persistent allergy?
> 4 days/week
AND >4 consecutive weeks
What is mild allergy according to ARIA?
All of:
Normal Sleep
No impairment (activities, work)
Symptoms NOT troublesome
What is a moderate-severe allergy according to ARIA?
ONE OR MORE OF:
Sleep disturbance
Impairment of activities, work
Troublesome symptoms
How is allergy diagnosed?
Symptoms
Skin test
RAST
What is RAST?
Presence and levels of allergen specific IgE
What is the allergy skin test?
Response to known allergens, <15% false positives
What are the controls for the allergy skin test?
Positive control - saline
Negative control - histamine
What investigations can be performed for a patient presenting with allergy?
RAST Skin test Total serum IgE Nasal allergen challenge Nasal cytology
How is allergy treated?
Avoid allergy (education)
Pharmacotherapy
Immunotherapy
How does immunotherapy work in treatment for severe allergy?
Stops the patient from producing IgE
What drugs can be indicated for treatment of a patient with allergy?
Topical Intranasal steroids Systemic Steroids Antihistamines Sodium Cromoglycate Allergen Immunotherapy Anti-IgE
