What condition is represented by white spots on the nails usually caused by injury?

Leukonychia is the condition characterized by white spots on the nails, which typically occur as a result of minor trauma or injury to the nail matrix. When the nail matrix is injured, it may lead to abnormal keratinization, and the resulting air pockets can manifest as white spots or patches on the nail surface. These spots can appear following a bump or slight trauma, often without needing severe injury, and may grow out with the nail over time.

In contrast, eggshell nails refer to nails that are thin, weak, and curve over the free edge, often not directly related to trauma. Beau's lines are transverse ridges that form as a result of systemic conditions or severe stress and do not represent spots but rather entire lines across the nail. Onychorrhexis is characterized by brittle nails that exhibit longitudinal ridges and splits, again differing from the presentation of leukonychia. Thus, leukonychia represents the specific phenomenon of white spots due to nail injury.