What is the role of the IgE-mediated allergy in severe asthma?

Severe asthma (SA) is a heterogenous disease with multiple clinical phenotypes. 'Early atopic asthma' is the predominant phenotype in children with SA. This phenotype is also identified in adults with SA. However, the role of immunoglobulin E (IgE)-mediated allergy in SA is still under debate.

This review summarizes current evidence linking IgE-mediated sensitization to SA. Electronic search was realized in Medline and PubMed databases by using the following terms: 'severe asthma,' 'IgE-mediated' associated with 'environmental allergens,' 'aeroallergens,' 'house dust mites,' 'pollens,' 'pets,' 'moulds,' 'cockroach,' 'food allergy,' 'drug allergy,' 'venom allergy,' 'atopic dermatitis,' 'eczema,' 'anaphylaxis.' Exposure to most aeroallergens of SA patients with atopy is associated with an increased risk of severe exacerbations. Children with food allergy have more severe asthma, poor symptoms control, and a high hospitalization rate. More limited evidence exists for the other IgE-mediated conditions and SA.

IgE-mediated pathways play central role in the pathogenesis of various allergic diseases, including asthma. However, the allergic burden seems to be more important in children with SA than in adults. Future research may provide a better understanding of the role of IgE-mediated allergy in SA and coexisting allergic diseases with improvement in their clinical outcomes.