Which of the following is NOT considered a typical nail disorder?

Athlete's foot is primarily a fungal infection that affects the skin of the feet and is not classified as a nail disorder. It typically manifests between the toes or on the soles of the feet and can lead to additional issues such as itching, redness, and scaling. While it may indirectly impact the toenails if the infection spreads, it is fundamentally a skin condition rather than a direct disorder of the nails themselves.

In contrast, nail fungus, nail psoriasis, and nail biting are all conditions that directly affect the nails. Nail fungus refers to infections that cause discoloration and degradation of the nails. Nail psoriasis is a skin condition that can lead to pitting, discoloration, and other nail changes. Nail biting is a behavioral issue that many individuals experience, which can lead to damage to the nails and surrounding skin. Understanding these distinctions is crucial when identifying specific nail disorders in practice.