Asthma in preschool children is common. One in three children has at least one episode of wheezing prior to
their third birthday, and the cumulative prevalence of wheeze is almost 50% at the age of 6 years. The management of
these patients, especially when symptoms are recurrent and severe, is a challenging task. Clinical benefits of inhaled
corticosteroids in preschool asthmatic children are still controversial. Since leukotrienes are potent bronchoconstrictive
agents, the leukotriene receptor antagonists (LTRAs) are used in asthmatic patients to inhibit their action in the respiratory
tract. Montelukast, the only LTRA approved for young children use in several countries, is also known to have
antieosinophilic properties. This review summarizes the most recent evidence on the role of LTRAs, particularly
montelukast, in the treatment of preschool asthma. Montelukast seems to be effective in preschool asthma and recurrent
wheezing for improving symptoms, lung function, and bronchial inflammation, and for protecting against cold air-induced
bronchial hyperreactivity. The scarce data available do not allow to reach definitive conclusions on LTRAs efficacy in
acute asthma or in the obese-asthma phenotype. The excellent safety profile of montelukast and the convenience of oral
delivery, that entail better compliance from young children, represent the main strengths of its use in preschool children.
LTRAs represent a valid alternative to inhaled corticosteroids in young children, and are suggested mainly to reduce
virus-induced exacerbations, to overcome the difficulties due to the inhaled therapy, in subjects showing adverse effects
related to long-term steroid therapy, or when compliance is poor.