Final answer:
Onychatrophia is the nail disease not caused by a fungus; it is a condition where the nail atrophies. The other conditions listed are fungal infections caused by dermatophytes and treated with hygiene and antifungal medications.
Step-by-step explanation:
The nail disease that is NOT caused by a fungus is Onychatrophia. This condition results in the wasting away or atrophy of the nail, which could be due to injury or disease and it's not a fungal infection. In contrast, the other conditions listed — Tinea pedis (athlete's foot), Onychomycosis (nail fungus), and Tinea manus (a form of ringworm) — are all fungal infections caused by dermatophytes. These fungi secrete extracellular enzymes that break down keratin, a protein found in the skin, hair, and nails, thereby causing these conditions.
Tinea pedis, commonly known as athlete's foot, occurs on the feet, particularly between the toes, and causes symptoms like itching and burning. Onychomycosis manifests as an infection of the nail, making it yellow, brittle and prone to breaking. Tinea manus is a fungal infection similar to athlete's foot, but it occurs on the hands. Proper hygiene and antifungal medications are typically required to treat these fungal infections.