Final answer:
Skin with a fungal infection, like tinea, shows violet under a woods lamp due to the fluorescence of the fungal elements.
Step-by-step explanation:
The type of skin that shows violet under a woods lamp is skin that has a fungal infection, such as tinea. When a woods lamp with a wavelength of 365 nm is directed on the skin with a fungal infection, the ultraviolet light causes the fungal elements to fluoresce, appearing violet under the lamp.