BRONCHIAL ASTHMA

BRONCHIAL ASTHMAThe term Asthma comes from the Greek

verb aazein, meaning to pant, to exhale with the open mouth, sharp breath.

Asthma is a disease of airways it is characterised by increased responsiveness of tracheobronchial tree toa variety of stimuli resulting in widespread narrowing of the air passages which may be relieved spontaneously or by therapy.

Status asthmaticus.

EPIDEMIOLOGY• All around the world 234 million people are

suffering from asthma.• India has an estimated 15-20 million

asthmatics.• Majority 50%asthmatics are below are 10

years of age.• Ratio between male:female =2:1

TYPES OF ASTHMABased on the stimuli initiating bronchial asthma, are of 3 types

EXTRINSIC

INTRINSIC

MIXED

EXTRINSIC ASTHMAAtopic ,allergic.Most common type of asthma Usually begins in childhood or in early adult life.Most patients of this type have personal or family

history of preceding allergic diseases.Hypersensitivity to various extrinsic allergic substances

or ALLERGENS is usually present in these cases.OCCUPATIONAL ASTHMA It is a variant of extrinsic asthmaAsthma is stimulated by fumes, gases and organic and

chemical dust.Allergic response is IgE mediated TYPE-1

hypersensitivity reaction.

ALLERGENS

ACUTE IMMEDIATE RESPONSE ALLERGEN

Stimulates the IgE sensitised mast cells

Mast cell degranulation occurs

Mediators like histamine Leukotriene prostaglandin, PAF and chemotactic factor for eosinophils and neutrophils.

Contd….. Results in Bronchoconstriction Oedema Mucus hypersecretion

and Accumulation of

eosinophils and

neutrophils.

PATHOPHYSIOLOGY

LATE PHASE REACTIONIt follows the acute immediate response and is

responsible for prolonged manifestations of asthma, Mobilisation of blood leucocytes mainly Basophils

along with Eosinophils and Neutrophils

leads to further release of inflammatory mediators

which accentuates brochoconstriction , oedema,…..

• Inflammatory injury is caused by Neutrophils and MBP of Eosinophils.

INTRINSIC ASTHMAIdiosyncratic,non-atopic.Seen in lateral adult life with negative

personal or family history of allergy , negative skin test ,normal serum levels of IgE.

Most of these patients develop acute typical symptom complex of asthma after an upper respiratory tract infection by virus.

Commonly associated with nasal polyp,emphysema and chronic bronchitis.

10% patients become hypersensitive to drugs mostly to small doses of aspirin- ASPIRIN SENSITIVE ASTHMA

MIXED TYPE OF ASTHMA

Many patients do not clearly fit into either of the above categories.

They have mixed features of both.

SIGNS & SYMPTOMS Dyspnoea Wheezing Cough Limitation of activity

PRECIPITATING FACTORS

INVESTIGATIONS

EosinophiliaDemonstration of CURSCHMANN’S

SPIRALS and CHARCOT-LAYDEN CRYSTALS in sputum.

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