[Guideline 'Treating asthma in children' for pediatric pulmonologists (2nd revised edition). I. Diagnosis and prevention].

The case history and physical examination form the corner-stones 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.