Which of the following is NOT a nail disease caused by fungus?

Onychocryptosis refers to an ingrown nail, which is primarily a condition related to the physical structure and growth of the nail rather than a fungal infection. It occurs when the edges of the nail grow into the surrounding skin, leading to pain, redness, and sometimes infection. This condition is influenced by factors like improper nail trimming or ill-fitting footwear.

In contrast, the other conditions listed are all fungal infections. Onychomycosis is a fungal infection specifically affecting the nails, causing them to become discolored and brittle. Tinea manus and tinea pedis are both fungal infections as well, affecting the hands and feet respectively. Thus, onychocryptosis stands out as the only option that does not involve a fungal component, making it the correct choice for this question.