Which of the following nail conditions involves the shedding of the nail bed and plate due to injury or allergy?

Onycholysis is the condition described in the question that involves the separation or shedding of the nail plate from the nail bed. This can occur due to various factors, including injuries to the nail area, allergic reactions to products used on the nails, or other underlying health conditions.

When onycholysis occurs, you will typically notice that the nail plate lifts away from the soft tissue underneath, which can lead to discomfort and increase the risk of infection. The condition can manifest as a gradual separation that may begin at the tip of the nail and progress toward the cuticle, making it essential to identify and address any underlying causes, such as trauma or allergy, to manage the symptoms effectively.

The other conditions listed do not align with the symptoms of shedding due to injury or allergy: onychomycosis is a fungal infection, onychocryptosis refers to ingrown nails, and onychorrhexis describes brittle nails with ridges or splits, none of which involve the shedding process as highlighted in the question.