The diagnosis of asthma in infants and preschool children relies on clinical judgement based on a combination of symptoms and physical findings, family history, the presence of other clinical atopic disease (eczema and allergic rhinitis) and response to bronchodilators.

Wheezing in infants up to 12 months old is most commonly transient and due to either acute viral bronchiolitis or to the presence of relatively small and/or floppy airways, which produces noisy breathing but no associated morbidity. Neither of these forms of infant wheeze respond to anti-asthma therapy.

When cough is the predominant symptom of suspected asthma in a young child, careful assessment is needed to avoid making an incorrect diagnosis of asthma, or instigating inappropriate treatment. The absence of wheeze and/or shortness of breath makes asthma unlikely. Cough alone (recurrent non-specific cough) is most likely due to recurrent viral bronchitis, which is unresponsive to both bronchodilators and preventive therapy including inhaled corticosteroids (ICS). Recurrent non-specific cough usually resolves by age 6 or 7 years and leaves no residual pulmonary pathology.

Asthma management in children should be based on a careful assessment of the clinical pattern. Childhood asthma is classified as infrequent intermittent, frequent intermittent, mild persistent, moderate persistent or severe persistent (Figure 1). This classification is based mainly on clinical information, but spirometry and peak expiratory flow variability can provide useful additional information in children older than 7 years. The initial assessment should be reviewed regularly. For guidelines on assessment and classification of asthma pattern and severity in children, see Asthma Management Handbook 2006.¹

Intermittent asthma accounts for up to 95% of childhood asthma.² Because episodes are usually triggered by a viral upper respiratory tract infection, the terms “intermittent asthma” and “virus-associated wheeze” or “viral-induced wheeze” are sometimes used synonymously in clinical literature.³

Typical patterns of deterioration in symptoms or fall in lung function parameters over time, relative to good asthma control (horizontal lines).

Montelukast is currently recommended as a treatment option for children with frequent intermittent asthma or mild persistent asthma.