- The case history and physical examination form the cornerstones for asthma diagnosis.

- Establishing the correct diagnosis may be difficult in infants and preschool children; in such cases the progression of the symptoms over time is important.

- Routine laboratory and radiological investigations are advised against.

- Allergy testing may be useful in children under the age of 4 years.

- Lung function investigations can be used from the age of 5 to 6 years onwards.

- Non-invasive investigations into the degree of bronchial inflammation can be performed by measuring the fraction nitric oxide in exhaled air.

- House dust mite reduction is a useful measure for preventing asthma if sensitisation has been demonstrated.

- Breast-feeding during the first 4 to 6 months of life can be considered as a preventive measure in infants with an increased risk of developing asthma and allergy.