In the preparation of the unstained keratinophagous flakes, one can see the fungal hypha after dissolving the cell membrane with 20% potassium hydroxide (KOH). The borders of the cell can be still weakly recognized (magnification 400).Clinic: 42 year old patient. 5cm large erythematous, slightly exfoliative, irregular limited plaque on abdomen after contact to a guinea pig with tinea.