Asthma need not hamper
ASTHMA stands for ‘panting’ in Greek. A person with asthma has to pant for breath. There are a number of conditions which can produce severe breathlessness and simulate asthma, but unqualified asthma means bronchial asthma. The latter is a condition that causes narrowing and inflammation of the air tubes (bronchi). This causes difficulty in inhaling and even more in exhaling the air. Bronchial asthma is basically an allergic disorder which can be triggered off by a variety of allergens and is episodic in character. Heart failure (sometimes called cardiac asthama), acute respiratory infections, inhalation of foreign bodies, acute spasm of the larynx, chronic lung diseases can simulate bronchial asthma, leading to respiratory failure and, occasionally, emotionally disturbed conditions.
In India the
incidence, as reported in various studies conducted by the Department
of Pulmonary Medicine, PGI, has been reported to be 3 to 4 per cent in
the urban and half to one per cent in the rural population.
As an allergic disorder, asthma can be initiated by various factors known as triggers. For long it was believed that the main pathology in the respiratory tubes is the constriction or narrowing of these tubes by the contraction of smooth muscles in the walls of bronchi. This narrowing produces whistling noises when the air passes in and out of these narrowed tubes.
Wheezing, thus, is a hallmark of this disease. Other symptoms include cough and the constriction of chest. Apart from this constriction, there is also inflamation of the walls of bronchi.
A large number of cells infiltrate the walls in response to the allergic process and produce various chemicals which produce oedema and mucus plugging.
The modern treatment is directed at both the factors. A large number of persons suffering from asthma may have a family history of asthma or other allergic disorders. These people usually exhibit the symptoms early in life. The other group of asthmatics do not have this predisposition but can react to various allergens and stimuli. There is quite a bit of overlapping between both the groups and the treatment is similar.
Allergens/triggers of asthma
Given the predisposition of an individual, asthma can be triggered off by a variety of allergens. These include pollens of various plants, between the size of three to five microns. The bigger ones are trapped in the nose and thus cannot reach the lungs. The plants would vary from place to place, according to the ecology of the area. A study conducted by the Department of Paediatrics, PGI, suggests that in this area pollens of kikkar doov grass, arandi, neem and paper mulberry, are the common triggers. During the harvesting season, wheat husk serves as a trigger. Moulds which grow outdoors and even indoors in the humid environment can be the source of an allergy in the rainy season for many people. In the indoor conditions, house dust containing dust mites, animal danders and secretions (dogs, cats, rodents and others) can all be major triggers of Asthma. Cockroaches are suspected to be an important source of allergens also.
Infections are very important precipitating causes of an asthmatic attack not only in the predisposed people but sometimes in other individuals as well. After every outbreak of an upper respiratory infection, a large number of people keep coughing and wheezing for weeks after the infection is over. Most of these infections are viral in nature, but occasionally bacterial infections can bring on an attack. A very interesting observation has been made that some of the countries with hygienic conditions and less infections are more prone to allergic disorders in general.
The immunological response to various infections in children grooms the immune mechanism in such a way that they become more active against a person’s own tissues. During a discussion on this subject on BBC somebody said, "Should we then expose our children to diarrhoea and respiratory infections?" The answer is obviously "no". But the observation deserves a notice.
A large number of drugs can produce
an allergic response. Most notorious being the commonly-used aspirin
and other pain-killers. Theoretically, any drug is capable of
producing such a response. Air pollution can play havoc. The presence
of a large number of suspended dust particles, high concentration of
nitrogen oxide, ozone and to some extent sulphur dioxide can trigger
an asthmatic attack. Places like Delhi, Bombay, Kolkata and Ludhiana
have these triggers in plenty. Various industries, including food
processing, plastics, metallurgic, saw mills, diamond polishing etc of
which have a lot of dust can predispose individuals to asthma.
Finally, psychogenic factors like stress and anxiety can precipitate