Tricophyton rubrum in a case of tinea unguium phenotypic mycological diagnostic algorithm and its limits

: Trichophyton rubrum is the most common dermatophyte isolated from human dermatophytosis. We present the mycological diagnosis algorithm and results in an onychomycosis case--tinea unguium. Biological samples have been inoculated on both usual and special culture media and incubated at both 30 degrees C and 37 degrees C for a period of fourteen days. Based on the macroscopic and microscopic characters and on the physiological and biochemical tests results, we identified a Trichophyton rubrum granular type dermatophyte. We are discussing phenotypic mycological diagnosis limits and molecular diagnostic benefits for rapid setting up of fungal therapy in order to avoid chronic mycosis and their complications.