Approaches to reduce the risk of severe asthma in children with preschool wheeze

INTRODUCTION: Asthma is a common, serious condition. We can treat the symptoms of mild-moderate disease, but severe asthma is life-threatening despite treatment. We cannot cure asthma and have no specific preventive strategies. AREAS COVERED: We performed a PubMed search using the terms 'Severe asthma' and 'Prevention' and 'Preschool wheeze' limited to children, humans and English language over the previous five years. We searched the bibliographies of relevant references and also our personal archives. We cover transgenerational, antenatal and early life factors which increase the risk of pre-school wheeze; the factors promoting or protecting the pre-school wheezer from developing school age asthma; and the factors leading to one of the three types of severe asthma defined by WHO (untreated, difficult to treat, and treatment resistant). EXPERT OPINION: Currently we have no pharmacological preventive strategies. Risk can be reduced by public health measures such as reduction in smoking and environmental pollution, and there are tantalizing hints from comparison of farming to other environments that exploring how environmental modulation may lead to more specific, personalized strategies. The effects of the new RSV prevention strategies are awaited. We need a better understanding of the pathways driving disease progression, and biomarkers of risk. Asthma is one of the most common non-communicable diseases worldwide and is incurable. We can often treat the symptoms of mild-to-moderate asthma effectively, but severe asthma may be refractory and severely impair quality of life. Prevention would therefore be optimal. Prevention of severe asthma could be via preventing asthma developing at all or preventing progression to severe disease. The roots of asthma are transgenerational, antenatal and in the early years, and we describe possible ways of intervening to prevent asthma across the developmental spectrum. Significant risk reduction can be achieved by public health measures such as reductions in smoking, air pollution and child poverty, but we have no specific personalized therapies to reduce risk. The most promising avenue arises from the observation that babies born on cattle or poultry farms have a low risk of allergies and asthma, perhaps related to increased bacterial and fungal diversity in the environment, and early innate immune stimulation, but more work is needed. If mild-moderate asthma is not to become severe, active, which may be subclinical inflammation needs to be treated aggressively. Also, important is education to get the basic management steps, and, especially in low resource settings, ensuring that essential asthma medications are made available. eng

• Bush, A.
• Schaub, B.