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

BACKGROUND

Traditional diagnostic testing for dermatophyte infection currently requires skin scraping for light microscopy and/or fungal culture or skin biopsy. Immunofluorescent microscopy can also be used with calcofluor stain. All of these tests can be time-consuming to perform, require a waiting period for results, and are invasive. We investigated the use of a real-time, noninvasive, confocal microscope in visualizing dermatophyte hyphae in vivo.

OBSERVATIONS: Confocal microscopic imaging of active tinea can clearly identify dermatophyte hyphae within the upper epidermis after potassium hydroxide application. The hyphae appear as bright linear branching objects not found in uninvolved skin.

CONCLUSIONS

It is possible to immediately and painlessly image dermatophyte hyphae in active lesions of tinea by means of a confocal microscope. With further improvement, imaging devices may be available to physicians to instantly and noninvasively evaluate a variety of skin disorders in microscopic detail.