Definition of Asthma
Why do we define asthma?
We define asthma to identify the disease correctly and to differentiate it from other diseases. To fulfill this goal, definition of asthma has been changing over last 40 years. The clinician, physiologist, immunologist, pathologist or epidemiologist - all have different perspective of asthma.
In the year 1997, the following working definition has been formulated by Expert Panel-2 of National Asthma Education and Prevention Program, USA.
Asthma is a chronic inflammatory disorder of the airways:
in which many cells & cellular elements play a role: in particular, mast cells, eosinophils, T lymphocytes, macrophages, neutrophil & epithelial cells.
- In susceptible individuals, this inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness and coughing, particularly at night or in the early morning.
- These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment.
- The inflammation also causes an associated increase in the existing bronchial hyper-responsiveness to a variety of stimuli.
- Moreover recent evidence indicates that sub-basement membrane fibrosis may occur in some patients with asthma and that these changes contribute to persistent abnormalities in lung function.
This definition consists of five components :
- Nature of disease
- Cardinal features
- Reversible obstruction in pulmonary function testing
- Hyper responsiveness to multiple stimuli
- Cause of persistent asthma
This definition is to some extent a complete definition. The critical role of inflammation in asthma is so important that it is described in the first component of the definition.
We can summaries this definition in a simple form:
Asthma is a chronic inflammatory disorder causing hyper responsiveness of airways to certain stimuli resulting in recurrent variable airflow limitation, at least partly reversible, presenting as wheezing, breathlessness, chest tightness and coughing.
See Also:
Etiology of Asthma
Classification of Asthma
Diagnosis of Asthma
Investigation of Asthma
Medicines of Asthma
Further Reading:
Topics:
What are the medicines used to treat asthma?
There are basically three kinds of medicines:
Relievers (Bronchodilators) are medicines that relax smooth muscles that have tightened around the airways. They relieve asthma symptoms. Short acting b2-agonists, short acting aminophylline, and ipratropium are bronchodilators or relievers.
Why we investigate asthma patients?
- For classification and assessment of severity
- For diagnosis of concomitant illness
- For exclusion of other causes of cough, wheeze dyspnoea or chest tightness
What are the investigations for asthma?
We should do four basic investigations of all patients.
1. Blood for TC, DC, ESR,
Hb% and :
What Causes Asthma Episodes?
The exact etiology or causes of asthma is still unknown. The airways of the asthmatics are found to be inflamed, red and hypersensitive. It is known that some triggers induce an asthma attack if exposed to the inflamed airways. Therefore, the management plan for asthma is directed towards prevention of inflammation of the airway and avoidance of triggers for the better control of symptoms.
What is a trigger?
What is step care management?
Step Care Management is like a staircase. We start treatment at the appropriate step. Then we shall step up along the stairs if asthma is not controlled or becomes more severe and shall step down when patient's asthma is fully controlled for 3 months or more.
We have divided the asthma management plan into five steps. At first, we should understand basic principles of five steps. Then we can construct any step by combining available drugs.
Basic Principles of Step Care Management
There are some common concerns about Asthma prevailing in the society. In majority of cases, these are misconceptions or baseless fears. For optimum control of asthma, these points should be dealt with proper care. Otherwise the management plan may go in vain. It the physicians responsibility to eradicate such worries, if present, from the patient’s mind. Some common concerns and suggested clinicians responses are listed below. Model answers to some frequently asked questions (FAQs) are also given. These will help the physician to deal with such situations more confidently.
What are the Diagnostic Criteria of Asthma?
There are four diagnostic criteria of asthma:
1. Cardinal features of asthma
- Paroxysmal respiratory distress
- Recurrent cough
- Wheeze
- Chest tightness
2. Recurrent attack due to multiple stimuli
3. Features of Eosinophilic inflammation: Sputum Eosinophilia
4. PFT: obstructive defects, at least partially reversible by drug
Why management at home ?
Since asthma is a chronic disease, it can be and should be managed at home up to a certain level. If home management plan is applied intelligently and skillfully, most asthmatics can lead symptom free normal life, avoid hospitalization thereby cutting down the financial expenditure significantly. All patients of asthma, except those with acute exacerbation, should be treated at home.
What are the components of home management plan ?
Comments
Post new comment