Allergic RhinitisHypersensitivity type-I

Fadel Muhammad Garishah

Review on Clinical Immunology Faculty of Medicine Universitas Diponegoro

Clinical Case

A 10 years old boy came to the Physician with his mother, complaining about his endless-influenza-like illness in the summer. The boy has to stay in his Granny’s house during the summer, and that diseases always come. He gets better when he comes home.

His Granny’s house is located near by flower-garden as his Grandfather is a gardener and flowers distributor.

Clinical symptoms

• Sneezing and flu-like illness when contact with the allergen

• Mucosal edema• Redness• Hypersecretion

of mucus

Introduction

• Rhinitis is an inflammation of the nasal mucous layer

• Allergic rhinitis/hay fever is initiated by hypersensitivity reactions to one of a large group of allergens, most commonly plant pollen, fungi, animal allergens and dust mites.

• Affects 20% US Population• IgE mediated (early- and late-phase) immediate

hypersensitivity (type I)

Classification

• Seasonal allergic rhinitis (SAR): happening at the same time each year, (Spring/Summer where pollen spreaded all the air)

• Perrenial allergic rhinitis (PAR): happening everytime in a year, (mainly caused by dust, animal allergen, fungi, cockroach)

• Occupational allergic rhinitis: related to occupation

Immunopathology I

1. Sensitization • Allergen bind to B-Cell as

APC, transformed into Plasma cell secreting IgE

• IgE bind to FcεRI of Mast cell/Basophils.

• This will be a memory-fuction to allergen

• Th2 Mediated the spreading of allergen introduction.

Immunopathology II

2. Allergic Response• Repeat exposure to

allergen• Activation of mast

cells/basophils in large number in nasal mucosa.

• Degranulation and releasing many allergic-response mediators

Effects of Allergic Response in Rhinitis• Vasoactive amines.

The most important mast cell–derived amine is histamine. Histamine causes intense smooth muscle contraction, increased vascular permeability, and increased mucus secretion by nasal

• Histamine, PAF, Leukotrienes C4, D4, E4 Neutral proteases that activate complement and kinins, Prostaglandin D2 : Vasodilation, increased vascular permeability

• Edema of the nasal mucous• Redness around the nose, the mediator of

inflammatory cause itchy• Increasing of mucous secret worse the breathing• Stimulation of the sneezing mechanism repeatedly by

p-substances? Neuropeptides?