Dermatophytes are keratinolytic fungi responsible for a large variety of diseases that can affect glabrous skin, nails and
hair. In many cases, the diagnosis is not clinically obvious, and mycological analysis is required. This includes both direct
microscopic examination and cultures. First of all, clinical specimens have to be sampled according to localization and characteristics
of the lesions. Direct microscopic examination is usually performed using clearing reagents (KOH or Amman’s chloral-lactophenol),
but its sensitivity may be greatly enhanced by the use of stains or fluorochromes such as Congo red or Calcofluor white. Histological
analysis is an efficient method, but it is constraining for the patients and, as direct examination, it does not allow precise
identification of the pathogen. Cultures are therefore needed, and specific culture media may be used to overcome the growth
of rapidly growing contaminating moulds which may hamper the recovery of dermatophytes. Identification at the species level
which may be useful to initiate an appropriate treatment or for setting prophylactic measures, relies on macroscopic and microscopic
morphology. Subcultures on culture media which stimulate conidiation and, for some species, the production of pigments, are
often necessary. Additionally, in case of atypical isolates, some biochemical or physiological tests may be performed such
as the search for urease activity or the in vitro hair perforation test. However, their contribution to species identification
is rather limited, and progress is still needed for the development of biochemical or immunological tests allowing an accurate
identification at the species level, pending for the availability of molecular biology-based kits.
Keywords Dermatophytes - Mycological analysis - Direct examination - Culture - Specific culture media