2. What is Asthma?
• Heterogenous disease
• Chronic airway inflammation
• Expiratory airflow obstruction
• Symptoms
• Wheezing
• Shortness of breath
• Chest tightness
• cough
3. Major subtypes
• AtopicAsthma
• Type 1 hypersensitivity
• Childhood
• Environmental allergens
• Positive family history
• High total serum IgE levels
• Serum radioallergosorbent tests
• NonAtopic asthma
• No evidence of sensitization
• Less common family history
• Associated with
• Viral respiratory infections
• Air pollutants
• Cold
4. Major subtypes
• Occupational asthma
• Fumes
• Dusts
• Chemicals
• Even minute quantities are
sufficient
• Repeated exposure
• Drug – Induced asthma
• Aspirin sensitive asthma
• NSAIDs
• Associated with utricaria
Inhibition of COX
Arachidonic acid not
metobolised
Less Prostaglandin E2
6. Th2 responses, IgE and Inflammation
Th2 cells
IL -4
Ig E
production
IL – 5
Eosinophil
recruitment
IL – 13
Endobronchial
Secretions
Th 17
IL – 17
Neutrophil
recruitment