Asthma UK states that if more allergy tests (including dust mite, pollen, animal dander, food and mould) were carried out then patients (and their carers) would be able to avoid their triggers and thus manage their own illness better. Two thirds do not know what their triggers are!
Moulds in particular are increasingly coming under suspicion as having a lot more involvement in uncontrolled asthma than previously suspected. Severe Asthma with Fungal Sensitisation (SAFS) is a fairly new concept that affects roughly half of all severe, uncontrolled asthmatics. Treatment with an oral antifungal is known to benefit such patients.
Treatment options in severe fungal asthma and allergic bronchopulmonary aspergillosis