Background: Childhood asthma is a significant public health problem and severe exacerbation can result in diminished quality of life and hospitalisation. Objective: To examine the contribution of outdoor fungi to childhood and adolescent asthma hospitalisations Methods: The Melbourne Air Pollen Children and Adolescent (MAPCAH) study is a case-crossover study of 644 children and adolescents (aged 2-17 years) hospitalised for asthma between September 2009 and December 2011. MAPCAH collected individual data on human rhinovirus (HRV) infection and fungal sensitisation; and daily counts of ambient …