In New Zealand, one in seven children, aged 2-14 years, were treated for asthma in 2011-2013. Ethnic-specific differences in asthma have been described in New Zealand, whereby Maori and Pacific children are more likely to be hospitalised due to asthma and have higher asthma-related mortality rates.

Obesity is now recognized as a major risk factor for asthma and several longitudinal epidemiological studies show that obesity often precedes incident asthma. Increasing consumption of sugar represents one possible contributor to obesity and obesity is also associated with increased asthma severity, poorer disease control and lower quality of life.

The study will also explore a possible link between scabies and asthma, as there are a number of shared features of the immune response to scabies and asthma. Another unpublished study has shown that children with a past diagnosis of scabies are at an increased risk of asthma compared to children with no such history.

The study will consider the role of other possible risk factors for asthma, such as maternal smoking, indoor dampness and breast feeding, which will be treated as potential confounders.

Since the primary cause of asthma is unknown, our study could contribute to giving statistical evidence of association between these competing hypotheses discussed above. Since asthma contributes to ethnic inequality in health status, such a study has the potential to reduce inequity, since dietary factors and scabies are potentially modifiable.