ABSTRACT
Dermatophytes belong to the oldest groups of microorganisms that were recognized as agents of human diseases. Sixteen species of dermatophytes associated with human diseases were introduced between 1870 and 1920, and Sabouraud, with a magisterial vision, defined a new classification system, subdividing these species into four genera: Achorion, Trichophyton, Microsporum, and Epidermophyton. The 1960s marked a new phase in the knowledge of dermatophytes, with the rediscovery of the sexual reproduction of some species. The clinical aspects of dermatophytic lesions are highly varied and result from the combination of the destruction of keratin with an inflammatory response, which is more or less intense depending on the parasite-host relationship. The laboratory diagnosis of dermatophytoses, as for other fungal infections, involves three distinct phases: pre-analytical phase; analytical phase; and post-analytical phase. The urease production test is widely used to identify dermatophytes, and is particularly useful to differentiate Trichophyton interdigitale from the other species of Trichophyton.
