Many asthma sufferers are known to the sensitised to fungi - a condition known as Severe Asthma with Fungal Sensitisation (SAFS). A similar series of studies on the more severe form of asthma known as Allergic Bronchopulmonary Aspergillosis (ABPA) has shown a beneficial effect of treatment with antifungals.
ABPA patients are known to have Aspergillus growing in their lungs so it is logical that antifungal medication will ease the infection - though it is very unusual that the antifungal would be able to eradicate the infection completely. ABPA is treated long term with steroids to control the inflammation caused by the fungus. Long term use of steroids can be very unpleasant as there are many potential side-effects. Treatment with antifungals lessens the symptoms and therefore allows a reduction in the use of steroids, bringing about a reduction in unpleasant side effects.
Of course antifungals such as itraconazole can also have side effects so close monitoring is required in the initial stages of treatment.
SAFS patients are not known to have fungi growing in their lungs and have much lower detected fungal contact as measured by IgE, so it is not as clear whether or not treatment with an antifungal drug would help ease the asthma symptoms.
Denning et al. sets out to assess whether patients with SAFS respond to treatment with an antifungal drug. Patients with sensitivity to at least one of a panel of seven fungi were recruited, but those with very high IgE were rejected so to exclude ABPA. Treatment with itraconazole for up to 32 weeks gave a significant improvement in quality of life and reduced IgE score.
Antifungal use to treat this group of patients does therefore have some evidence to support it as a viable treatment option, and hints at direct fungal involvment in some severe asthma.
Manchester University link