A better potassium hydroxide preparation? In vivo diagnosis of tinea with confocal microscopy

Background: Traditional diagnostic testing for dermatophyte infection curre ntly requires skin scraping for light microscopy and/or fungal culture or s kin biopsy. Immunofluorescent microscopy can also be used with calcofluor s tain. All of these tests can be time-consuming to perform, require a waitin g period for results, and are invasive. We investigated the use of a real-t ime, noninvasive, confocal microscope in visualizing dermatophyte hyphae in vivo. Observations: Confocal microscopic imaging of active tinea can clearly iden tify dermatophyte hyphae within the upper epidermis after potassium hydroxi de application. The hyphae appear as bright linear branching objects not fo und in uninvolved skin. Conclusions: it is possible to immediately and painlessly image dermatophyt e hyphae in active lesions of tinea by means of a confocal microscope. With further improvement, imaging devices may be available to physicians to ins tantly and noninvasively evaluate a variety of skin disorders in microscopi c detail.