New diagnostic methods in dermatological mycology

In dermatological mycology, direct microscopy and culture are the main diagnostic procedures. Microscopic examination of a wet KOH preparation is usually satisfactory for the detection of the infecting organism based on the morphological characteristics of the fungal elements. However, examination of the KOH mount requires skill and experience. In order to help the unskilled personnel to recognize fungal elements by microscopic examination, a number of differential strains have been described. Great strides have been made to improve the sensitivity and specificity of direct microscopy for the detection of fungi also on chemical properties of the fungal cell wall. Thus fluorescence microscopy using fluorescent brighteners, e.g. Blancophor BA holds great promise for its wide application in dermatologic mycology. Culture media enjoy considerable application in the isolation and identification of dermatophytes and Candida species from clinical specimens. Some novel media have been formulated recently to assist in the early detection and identification of some fastidious dermatophytes e.g. Trichophyton verrucosum. In dermatological mycology the predictive diagnostic value of the diagnostic tests has to be delineated for each disease state. As an example, direct microscopy is a useful diagnostic procedure for the detection of dermatophytes and Pityrosporum-yeasts in clinical materials, but less valuable for the detection of Candida. Furthermore, considerable attention needs to be focused on the utilization of new and old diagnostic tests from a series of viewpoints including necessity, usefulness, clinical relevance and cost-benefit analysis.