CRITERIA FOR MAKING THE DIAGNOSING OF ASTHMA
BOX 2. Features used in making diagnosing of asthma
1. A history of variable respiratory symptoms
Typical symptoms are wheeze, shortness of breath, chest tightness, cough
- People with asthma generally have more than one of these symptoms
- The symptoms occur variably over time and vary in intensity
- The symptoms often occur or are worse at night or on waking
- Symptoms are often triggered by exercise, laughter, allergens or cold air
- Symptoms often occur with out worsen with viral infections
2. Evidence of variable expiratory airflow limitation
- At least once during the diagnostic process when FEV1 is low, document that the FEV1/FVE ratio is reduced. The FEV1/FVE ratio is normally more then 0.75-0.80 in adults, and more than 0.90 in children.
- Document that variation in lung function is greater than in healthy people. For example
FEV1 increases by more than 12% and 200 mL (in children,>12% of the predicted value) after inhaling a bronchodilator. This is called ‘c reversibility’.
Average daily diurnal PEF variability is > 10% (in children,>13%)
FEV1 increases by more than 12% and 200mL from baseline (in children,>12% of the predicted value) after 4 week of anti-inflammatory treatment (outside respiratory infection)
- The greater the variation, or the more time excess variation is seen, the more confident you can be of the diagnosis.
- Testing may need to be repeated during severe exacerbations or viral infections. If bronchodilator reversibility is not present when it is first tested, the next step depends on the clinical urgency and availability of other tests.
- For other tests to assist in diagnosis. Including bronchial challenge tests, see chapter 1 the GINA 2015 report.
**calculated from twice daily readings (best of 3 each time), as (the day’s highest PEF minus the day’s lowest PEF) divided by the mean of the day’s highest and lowest PEF, and averaged 1-2 week. If using PEF or in the office, use the same PEF meter each time
Physical examination in people with asthma is often normal, but the most frequent finding wheezing on auscultation on forced expiration.