allergic rhinitis richard douglas. prevalence most common disease 20% adult population
TRANSCRIPT
Allergic Rhinitis
Richard Douglas
Prevalence
• Most common disease
• 20% adult population
Diagnosis
• What’s the problem?
nasal blockage
clear rhinorrhoea
sneezing
itchy eyes
Diagnosis
• When during the year do you get these symptoms?
perennial
worse in springtime
Pathogenesis
• IgE mediated hypersensitivity to common aeroallergens
• Release of histamines, leukotrienes
More history
• Previous medicationsoccasional antihistamine, Otrivine spray
• Past medical historymild asthma as child
• Drug allergiesnil
Examination
• Headlight, Thuddicum’s speculum
• Nasendoscope
• Otoscope
Investigations
• Skin prick tests
Atopy
• Atopy is an inherited predisposition to produce IgE to environmental allergens
Non-atopics
Atopics
AllergicRhinitis
Differential diagnosis
• Allergic rhinitis
• Non-allergic rhinitis with eosinophilia
• Vasomotor rhinitis
Treatment
• Drugs
• Allergen avoidance
• Immunotherapy
• Surgery
Drugs
• AntihistaminesIntermittent symptomsWork quicklyExpensive
• Intranasal steroidsConstant symptomsSlow onset of actionInexpensive
Nasal Obstruction
Allergen avoidance
• Grass pollen difficult to avoid
• Best trial of dust mite avoidance shows no effect on allergic rhinitis
Immunotherapy
• Repeated exposure to high doses of allergen causes anergy
• Low dose to high dose
• Three year course
• Risk of anaphylaxis
• Highly effective when the allergen is known
What is the role of surgery?
•Highly effective
•Submucosal resection for good long term results