IGHE and asthma: Secondary outcomes include Composite Asthma Severity Index, Paediatric Asthma Quality of Life Questionnaire, lung function measures (forced expiratory volume in one second (FEV1), bronchodilator reversibility), fractional exhaled nitric oxide, Asthma Control Test (ACT), health outcomes EuroQol 5 Dimension (EQ-5D) and optimal serum IgE and blood eosinophil levels that may predict a response to therapy.