Fungal allergy in asthma

Fungal exposure is universal and fungi can be linked to asthma in a variety of ways. Fungal allergy drives asthma severity and long-term or uncontrolled fungal infection are associated with a poor control of asthma, complications such as bronchiectasies and chronic pulmonary aspergillosis. The first evidence of the link between the severity of asthma and fungal sensitization dates 1978, when Schwartz et al. demonstrated a relationship between asthma severity and Aspergillus spp sensitization. Alternaria or Cladosporium spp were associated with asthma severity in the European Community Respiratory Health Survey. The term “Severe Asthma with Fungal Sensitization” (SAFS) was introduced by Denning et al. in 2006, to indicate those patients who have persistent severe asthma (despite standard treatment) and evidence of fungal sensitization, as defined by positive prick testing, or fungus or fungal antigen-specific blood IgE testing, and do not meet the criteria for Allergic Bronchopulmonary Aspergillosis (ABPA). Proposed classification by a European Academy of Allergy and Clinical Immunology (EAACI) Task Force sets the total IgE cutoff at <1000 IU/ml for SAFS and >1000 IU/ml for ABPA. ABPA was accepted as an endotype, while SAFS was not and remains a pragmatic definition. ABPA may develop in asthmatics with a genetic predisposition and therefore SAFS may have the same background. Long-term antibiotic therapy may allow a reduction of exacerbations and recurrent infections, representing a cornerstone in the management of asthma and fungal sensitization.