Bronchial asthma is a chronic inflammatory disease of the airways characterized by increased responsiveness of the tracheobronchial tree. It causes narrowing of the air passages and symptoms like dyspnea, cough, chest tightness, and wheezing. There are two main types - extrinsic (allergic) asthma which is a type 1 hypersensitivity reaction to allergens, and intrinsic asthma which has no known trigger. Pathophysiologically, asthma involves airway hyperresponsiveness, inflammation, and airflow limitation that usually reverses with treatment.

1. Bronchial asthmaBronchial asthma
BYBY
PINAK SAINIPINAK SAINI

2. Bronchial asthma Bronchial asthma
 Asthma is defined as a chronic inflammatory disease of airwaysAsthma is defined as a chronic inflammatory disease of airways
that is characterized by increased responsiveness of thethat is characterized by increased responsiveness of the
tracheobronchial tree to a multiplicity of stimuli.tracheobronchial tree to a multiplicity of stimuli.
 It is manifested physiologically by a widespread narrowing of theIt is manifested physiologically by a widespread narrowing of the
air passages, which may be relieved spontaneously or as a resultair passages, which may be relieved spontaneously or as a result
of therapy,of therapy,
 And clinically by of dyspnoea, cough, chest tightness andAnd clinically by of dyspnoea, cough, chest tightness and
wheezing.wheezing.

3. TypesTypes
 A). ClinicallyA). Clinically
 Episodic asthma- symptom free in between EpisodesEpisodic asthma- symptom free in between Episodes
 Severe acute asthma- live threatening attacks of DyspnoeaSevere acute asthma- live threatening attacks of Dyspnoea
 Chronic asthma- persistence of Symptoms without any symptom freeChronic asthma- persistence of Symptoms without any symptom free
periodperiod
B). AetiologicallyB). Aetiologically
 Extrinsic AsthmaExtrinsic Asthma (Early onset Asthma/Allergic/Atopic Asthma)-(Early onset Asthma/Allergic/Atopic Asthma)-
Specific immunoglobulin (IGE) are produced in response to allergensSpecific immunoglobulin (IGE) are produced in response to allergens
 Intrinsic AsthmaIntrinsic Asthma (Late onset Asthma/ idiosyncratic/Non Atopic(Late onset Asthma/ idiosyncratic/Non Atopic
Asthma) – There is no role of allergen in the production of disease.Asthma) – There is no role of allergen in the production of disease.
 MixedMixed

4. EXTRINSIC : - Atopic or allergic : -EXTRINSIC : - Atopic or allergic : -
 most common formmost common form
 Usually begins in childhood and have personal & family history ofUsually begins in childhood and have personal & family history of
allergies to pollens, dusts, animal dander, moulds some chemicalallergies to pollens, dusts, animal dander, moulds some chemical
fumes if working in a factory.fumes if working in a factory.
 They have high level of IgE and gives positive skin test with theThey have high level of IgE and gives positive skin test with the
specific allergen representing Type I hypersensitivity mediated byspecific allergen representing Type I hypersensitivity mediated by
IgE antibodies.IgE antibodies.

5.  This is type I reaction which may be immediate & lateThis is type I reaction which may be immediate & late

6.  Immediate response : -Immediate response : - Occurs within minutesOccurs within minutes
• Binding of antigen (allergen) with Ig E coated mast cells & releasingBinding of antigen (allergen) with Ig E coated mast cells & releasing
Primary mediators – Histamine, neutrophil chemotatic factor, eosinophilPrimary mediators – Histamine, neutrophil chemotatic factor, eosinophil
chemotactic factor &chemotactic factor &
Secondary mediators – Cytokines – IL-1, TNF & IL6, Leukotrienes-Secondary mediators – Cytokines – IL-1, TNF & IL6, Leukotrienes-
B4,C4,D4, Prostaglandin D2, Platelet activating factorB4,C4,D4, Prostaglandin D2, Platelet activating factor
• There is bronchospasm, eodema, mucus secretion , & infiltration ofThere is bronchospasm, eodema, mucus secretion , & infiltration of
leucocytesleucocytes
• They release a second wave of mediators that cause late reactionThey release a second wave of mediators that cause late reaction

7. Late phase response : -Late phase response : -
 This follows the acute phase.This follows the acute phase.
 This is due to excessive mobilization of neutrophils, eosinophils andThis is due to excessive mobilization of neutrophils, eosinophils and
basophils.basophils.
 ThisThis results in a continuous & prolonged release of mediators,results in a continuous & prolonged release of mediators,
which acctuated the above mentioned effects.which acctuated the above mentioned effects.
 There is persistant bronchospasm, oedema, leucocyte infiltration &There is persistant bronchospasm, oedema, leucocyte infiltration &
necrosis of epithelial cellsnecrosis of epithelial cells

8. 2)2) Intrinsic or Idiosyncratic, non atopic : -Intrinsic or Idiosyncratic, non atopic : -
 This has been seen in persons due to some unknown intrinsicThis has been seen in persons due to some unknown intrinsic
reason because they do not have any personal or family history ofreason because they do not have any personal or family history of
allergies, they are of negative skin test, normal serum IgE in theirallergies, they are of negative skin test, normal serum IgE in their
adult lifeadult life
 3) Mixed type : -3) Mixed type : - Many patient do not clearly fit into any singleMany patient do not clearly fit into any single
type having features of both.type having features of both.

9. Pathophysiological features of AsthmaPathophysiological features of Asthma
  Airway hyper responsivenessAirway hyper responsiveness- exaggerated Bronchial- exaggerated Bronchial
constriction to a wide range of non-Specific stimuli e.g. exercise, coldconstriction to a wide range of non-Specific stimuli e.g. exercise, cold
air.air.
  Airway InflammationAirway Inflammation- Muscle thickness, Oedema, increased- Muscle thickness, Oedema, increased
mucous secretion, mucous plugging, epithelial damage.mucous secretion, mucous plugging, epithelial damage.
  Airflow limitationAirflow limitation- usually reverses spontaneously or with- usually reverses spontaneously or with
treatmenttreatment

10. Morphology
Grossly:
1. The lungs are remarkably distended with air.
2. The airways are filled with thick, tenacious, adherent mucous plugs.
3. Lungs are over inflated with occlusion of air passages by viscid
mucus plugs.

11. cast of the bronchial tree inspissated mucus coughed up
by a patient during an asthmatic attack mucus plugs block
airways

12. Microscopically:
1. Plugs contain strips of epithelium and many eosinophils, needle-like
Charcot-Leyden crystals, the Curschmann spirals.

13. Microscopically cont..
2. Bronchial submucosal mucous glands are hyperplastic. An increase in
goblet cells.
3. The epithelial BM appears thickened.
4. The mucosa is edematous and contains a mixed inflammatory
infiltrate, including eosinophils.
5. Hyperplasia of bronchial smooth
muscle.