Relevant history
In order for the diagnosis of asthma to be reached, it is important to consider several factors in the patient’s relevant present and past history.
Environmental situation
The presence of atmospheric pollution due to the emission of nitrogen dioxide (from motor vehicles), sulphur dioxide (diesel fumes), airborne particles and grass, flower and crop pollens (such as rapeseed and soya crops), are proved by studies to exacerbate, or bring on, asthma.
Family history
It is important to go into the family history, to see if there is a tendency towards asthma, hay fever or eczema in other family members. If other immediate family members have such a history, the patient is more likely to develop asthma. In fact, first-degree relatives of an asthmatic (i.e. immediate family members) have a 10 times greater risk of developing asthma themselves, than other people.
History of childhood asthma
Once a person has suffered from asthma (i.e. as a child), the tendency to develop it again is always there, though the child may grow out of it.
Home situation
The change to a modern, urban, and “clean” environment seems to be especially associated with the increased prevalence of asthma, especially as people now spend 75% to 90% of their time indoors.
Things to look for are a dusty home environment (house dust mite), the presence of smokers in the house (smoke) and the presence of animals, such as dogs, cats, hamsters, horses, etc (animal dander).
Occupation
Has the asthma arisen because of exposure to a substance or material at work, to which the sufferer has become sensitised? Such materials may be paint sprays, chemicals or flour (See Occupational Asthma).
Smoking history
This is relevant, as there is some evidence to suggest that children who have been exposed to smoking, even in the womb, are more likely to develop asthma.
Trigger factors
As previously stated, the bronchioles in the lungs are excessively sensitive to various stimuli and this is a characteristic of the disease.
These stimuli are known as trigger factors and the patient reacts uniquely to these factors. The commonest are: -
- Viral or bacterial infections involving the respiratory tract, (i.e. the common cold or flu).
- Substances to which the patient has become sensitised such as house dust mites, secretions from cockroaches, pollens, animal skin cells (dander) and particles from feathers.
- Exercise especially in cold air or atmospheric temperature changes.
- Drugs (i.e. aspirin, Brufen (non steroidal anti-inflammatory).
- Psychological factors (i.e. acute stress and emotion, but not just “nerves”).
- Occupational triggers (materials such as chemicals, paint sprays, flour, etc).
Identifying trigger factors and thus avoiding them, is an important part of the individual’s management plan.
