Bronchial Asthma

Bronchial Asthma arises from spasm of the intrapulmonary bronchi.
It is characterized by wheezing and dyspnoea(shortness of breath).
Spasmodic attack of asthma varies in severity,but is usually temporary for short time,then clears up.
The subject is exposed to recurrent attacks at varied intervals.
Exist 2 types of causes:
1.Extrinsic causes:attack of asthma fallows inhalation of external antigenic substances(allergens).Atopic individuals are at-risk of developing asthma,due to hypersensitivity,usually to more than one,and rarely only one,antigen.
Allergenic substances provoking asthma attack:
-Dust:house dust,organic dust in industry.
-Pollen grains,animal hair and fur,bird feathers
-Some drugs as aspirin for exemple.
2.Intrinsic Causes:no history of hypersensitivity,no skin sensitivity reaction is given.So no apparent allergen can ba accused.
Intrinsic causes differs from extrinsic by:
-later age of onset
-more persistent attacks
-less response to bronchodilator drugs

Aggravation factors of asthma:
1.Allergenic substances that provoke extrinsic asthma attacks.
2.Nonspecific factors that may:
-precipitate asthma attack
-increase severity of existing attack(upper respiratory infection,inhalation of respiratory irritants as smoke,tobacco smoke,dust;physical exertion,muscular activity and exercise,emotional disorders as anxiety and anger.
3.Sometimes no obvious precipitating factor is found.

Prevention:
Primary prevention cannot be achieved,due to:
-causative agent is unknown in many cases,specially of intrinsic asthma.
-provoking/precipitating factors of asthmatic attack are not always practically available.
Preventive measures:
-sanitary,clean,plluation-free environment
-healthful lifestyle and open-air recreation
-avoiding exposure to provoking factors.No:smoking or passive smoking,exposure to polluted air,muscular exertion,emotional disturbance,drug abuse.