Leukonychia is a condition where white lines or dots appear on your finger or toenails. This is a very common issue and entirely harmless. Many healthy adults have these spots at some point in their lives, so developing them is likely not a sign of a serious medical condition. For some people, the white spots may appear as tiny dots speckled across the nail.
For others, the white spots may be larger and stretch across the entire nail. The spots may affect one nail or several. The most common cause of leukonychia is injury to the nail bed. These injuries can occur if you pinch or strike your nail or finger. Frequent manicures and pedicures or the use of gel or acrylic nails can also damage nail beds. Several other causes may be responsible for the unusual spots on the nails.
Causes. White spots or dots on your nails are common. Several issues can cause them. Possible causes include:
An allergy to a nail polish, gloss, hardener, or nail polish remover may cause white spots on your nails. The use of acrylic or gel nails can also badly damage your nails and may cause these white spots.
Fungi called white superficial onychomycosis can appear on the toenails. The first sign of the infection may be a few small white dots on the nails. The infection can grow and spread to the nail bed. Toenails may appear flaky and then become thick and brittle.
Injury to the nail. An injury at the base of your fingernail can cause white spots or dots on your nail as it grows. However, because of the time it takes for your fingernails to grow, you may not recall the injury. Some injuries won’t show up for four weeks or more.
Mineral deficiency. You may notice white spots or dots along your nails if you are deficient in certain minerals or vitamins. The deficiencies most commonly linked to this issue are zinc deficiency and calcium deficiency.
Additional causes. Less common causes for white spots on nails include:
renal (kidney) failure
psoriasis or eczema
While these causes are possible, they are very rare. Your doctor will likely explore a host of other conditions if you have persistent white spots on your nails before considering these more serious issues.
Symptoms. White spots can appear in a variety of ways. They may look like: tiny pen-point–sized dots, larger “lines” across the nail, larger individual dots. The cause for the white spots on your nail may dictate how the spots appear. A nail injury may cause a large white dot in the middle of the nail. An allergic reaction may cause several dots all over the nail. The appearance of the white dots or lines may be different on each nail.