Dermatophytoma: Recalcitrance to treatment because of existence of fungal biofilm.

Biofilms are populations of microorganisms that adhere to surfaces and produce an extracellular polysaccharide, increasing resistance to standard antimicrobials. This microbiologic principle may be beneficial in understanding refractory dermatophyte infections, such as dermatophytomas of the nail. In this condition, circumscribed dense white fungal masses live within and under the nail plate. Biofilm research could lead to finding new targets for antifungal therapy, including agents that reduce attachment of microorganisms, alter microorganisms' ability to synthesize extracellular matrix, and better penetrate the extracellular matrix to kill the organism contained with the biofilm.