Which nail condition is characterized by white spots on the nails?

The condition characterized by white spots on the nails is known as leukonychia. This condition can be caused by various factors, including minor trauma to the nail matrix, allergic reactions to nail products, or nutritional deficiencies. The white spots, also called leukonychia striata, typically appear as small, white lines or dots on the surface of the nails and are usually harmless.

In contrast, onychomycosis refers to a fungal infection of the nails, which often results in discoloration, thickening, and brittleness, but does not specifically cause white spots. Paronychia is an infection of the skin around the nails, leading to redness, swelling, and possible pus formation, rather than white spots on the nails themselves. Lastly, psoriasis can affect the nails, causing pitting, discoloration, and other changes, but it does not specifically lead to the appearance of white spots.