Prevention of asthma

Primary prevention of asthma is not easy to achieve. - Preventive measures which are useful in all children are prevention of passive smoking exposure in utero and/or in childhood and the use of breast-feeding during at least the first six months of life. - Single interventions towards reduction of house dust mite allergens are not effective in preventing asthma; only a combined intervention with breast feeding, stopping of passive smoking, and reduction of allergens of pets and house dust mite appeared to be effective in young children at risk for asthma. - In children with already existing asthma, a combination of (secondary) preventive measures with sanitation of the house, reduction of allergens of pets and house dust mite, and optimal ventilation is useful. - Removal of pets from homes of children in the general population before the onset of atopy and allergic disorders is not effective. - Children visiting day-care report more airway infections and respiratory complaints in the first years of life. However, the chance on asthma or atopy development in later life is not influenced. Therefore, there is no reason to avoid day-care attendance in the first years of life. - There is no evidence for the use of probiotics in order to prevent asthma. Their use is not advised. - The Dutch vaccination program does not increase the risk on atopy or asthma. - There is no evidence for the benefit of influenza vaccination in children with asthma. - Exposure to a dog or cat in already sensitised children with asthma is associated with more severe asthma. Therefore, pets are not advised with these children.