allergic rhinitis richard douglas. prevalence most common disease 20% adult population

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