Focus on Research Excellence

Associate Professor Jeroen Douwes
School of Public Health, Massey University

 

Up in the air - evaluating current asthma therapy

Over 20% of children in New Zealand suffer from asthma, which has long been seen as an allergic disease. Now, Associate Professor Jeroen Douwes from Massey University’s School of Public Health has conducted research that suggests that 50% of asthmatic children in this country may have a different type of the condition, which may require different treatment.

Asthma is the largest cause of child hospital admissions here, and in the past few decades its prevalence has doubled. It is a widespread problem in both adults and children worldwide and is a substantial cost to both our health system and families.
Internationally, it has long been believed that asthma is an allergic disease. Although non-allergic asthma was recognised, it was considered an anomaly that only occurred in a small proportion of patients, mostly adults. Because of this, the standard treatment for child asthma patients is with steroids.

Associate Professor Douwes had doubts about the commonly held view of the causes of asthma in children, and applied to the Health Research Council of New Zealand (HRC) for funding to investigate the fundamental assumptions of the current therapeutic regime. He wanted to find out if other types of childhood asthma could be identified, and if so, how common these are.

The research revealed a surprise – that half of the asthma cases studied may not be allergic. "This may explain why many children we are treating continue to have symptoms despite steroid treatment,” said Professor Peter Gibson, head of the University of Newcastle's Airways Research Centre, a key collaborator on the project. “We need to follow this up with treatment studies in those asthma sufferers who still have symptoms despite current treatment." However, it is important to remember that until these treatment studies have been carried out, people with asthma should stick to their management plan and follow current asthma guidelines.

The research raises several key questions for the medical community. What are the causes of non-allergic asthma? What can be done for the 50% of patients for whom the standard treatment may be ineffective? There are some intriguing clues which need further investigation. For example, children of farmers have a significantly lower prevalence of asthma. Why might this be?

Research so far indicates that animal contact for very young children or maternal contact with animals in pregnancy may help reduce the prevalence of asthma. A birth cohort study in rural New Zealand is underway to discover more specifically which factors give protection and which immunological mechanisms play a role. Once more is known about this, researchers can look at developing vaccines to target those immune mechanisms.