Reduction in the growth of non-dermatophyte moulds by itraconazole: evaluation by corneofungimetry assay

The activity of itraconazole against fungi of dermatological importance was studied using corneofungimetry performed on four test organisms: Aspergill us flavus, Fusarium oxysporum, Scopulariopsis brevicaulis and Scytalidium d imidiatum. The human stratum corneum used in the bioassay was harvested fro m healthy volunteers and from patients undergoing treatment with itraconazo le 200 mg daily for at least 2 weeks. A fungal mycelium grew on all untreat ed stratum corneum samples within 1 week. The pattern and extent of growth varied greatly among the test organisms. An inhibitory effect was observed on the itraconazole-treated samples. However, the level of inhibition was h igher than that expected by calculating itraconazole minimum inhibitory con centrations in a reference susceptibility test. It is concluded that some n on-dermatophyte moulds of medical importance can grow by forming hyphae on human stratum corneum. However, the process is partly inhibited by some unk nown mechanisms originating from the stratum corneum itself. It is further inhibited by the oral administration of itraconazole. This global effect mi ght be the result of the complementation inhibition due to the drug and/or some unknown components of the stratum corneum.