Chronic nail trauma, such as repeatedly starting and stopping, kicking, and other athletic endeavors, can cause damage to the nails that can look a lot like fungal nails. This sort of repetitive trauma can also occur with certain types of employment or wearing tight-fitting shoes. Some traumas may cause permanent changes that may mimic the appearance of fungal nails.
Other causative pathogens include Candida and nondermatophytic molds, in particular members of the mold genus Scytalidium (name recently changed to Neoscytalidium), Scopulariopsis, and Aspergillus. Candida species mainly cause fingernail onychomycosis in people whose hands are often submerged in water. Scytalidium mainly affects people in the tropics, though it persists if they later move to areas of temperate climate.
Athlete’s foot infections can be mild or severe. Some clear up quickly, and others last a long time. Athlete’s foot infections generally respond well to antifungal treatment. However, sometimes fungal infections are difficult to eliminate. Long-term treatment with antifungal medications may be necessary to keep athlete’s foot infections from returning.
Infected nails are usually thicker than normal and could be warped or oddly shaped. They can break easily. Nails with fungus might look yellow. Sometimes a white dot shows up on the nail and then gets bigger. When fungus builds up under your nail, it can loosen and even separate the nail from the bed. The fungus can also spread to the skin around your nail.