Both finger and toenails are usually pale pink in color, with a lighter crescent shape at the bottom of the nail known as the lunula. White spots can sometimes appear on the nail, which is referred to as punctate leukonychia. This condition can be caused by various factors, and in this blog post, we will discuss the different types of leukonychia, their causes, prevention, and treatment methods. 

• Punctate leukonychia, which presents as small white spots.
• Longitudinal leukonychia, which presents as a white band down the nail.
• Striate or transverse leukonychia, where one or more horizontal lines appear across the nail, parallel to the lunula. These are also sometimes called Mees lines.

• True leukonychia occurs when the white spot or line is caused by damage to the nail. In this case, the white areas remain unaffected when pressure is applied and will grow out as the nail does.
• Apparent leukonychia happens when the nail bed affects the color of the nail plate. The white spot or line will lessen or disappear under pressure and will not grow out with the nail.

Anyone can have white spots on their nails, regardless of their sex, age, or ethnicity.

Leukonychia can be caused by various factors, depending on the type:

Trauma

Injury to the nail plate or the matrix (the area where the nail grows from) can cause damage to the nail. This type of injury is common in children and is often the cause of white spots on the nail. Examples of such injuries include nail biting, manicures, day-to-day nail injuries, and wearing footwear that is too small, causing abnormal pressure on the nails. The white spots caused by these injuries will grow out with the nail.

Some forms of poisoning or medication can also cause leukonychia, although this is relatively rare and often results in transverse leukonychia.

• Heavy metal poisoning from metals, such as lead and arsenic
• Chemotherapy treatment for cancer, which is given by mouth, injection, or infusion through the skin to try and kill cancer cells or stop them from dividing
• Sulphonamides, a medication used for bacterial infections, such as skin infections, septicemia, and infections of the urinary tract

Systemic diseases can also cause white spots on the nails, signaling a problem elsewhere in the body. However, this is rarely the cause of white spots.

• Iron deficiency anemia, a lack of iron in the body
• Liver cirrhosis, which is scarring of the liver
• Kidney disease
• Heart failure
• Diabetes
• Problems with the digestion of proteins
• An excessive loss of proteins in the intestines
• Zinc deficiency
• Hyperthyroidism, an overactive thyroid resulting in abnormal levels of the thyroid hormone in the body
• Psoriasis
• Eczema

Fungal disease or infection of the nail, as well as skin diseases around the nail, can also cause white spots to appear.

• Bart-Pumphrey syndrome, which involves nail problems, knuckle issues, and deafness
• Buschkell-Gorlin syndrome, which involves nail problems, skin cysts, and kidney stones
• Bauer syndrome, which involves nail problems and skin cysts
• Darier disease, which involves wart-like blemishes on various parts of the body

Treatment for white spots on the nails will depend on the cause. If a doctor is uncertain of the cause, they may use several tests to help make a diagnosis, such as mycology (where fungi and nail clippings are sent away for study), nail biopsy (where a doctor removes a small piece of tissue for testing), or a blood test to identify if there is the presence of a systemic disease.

There is no specific treatment for white spots on nails alone. Those caused by trauma will naturally grow out over time. If the white spots are caused by something other than trauma, the doctor will need to identify the cause and treat it separately. If someone has any concerns over white spots on their nails, they should consult a doctor.

• Avoiding contact with irritant substances
• Avoiding excessive use of nail polish
• Cutting nails short
• Preventing nails from becoming dry by using moisturizer after washing

In most cases, white spots on the nail are not a problem and will go away in time.

The appearance of white spots on nails, or leukonychia, can be caused by various factors, including trauma, systemic illnesses, or hereditary conditions. Although most instances of white spots are harmless and will grow out over time, consulting a doctor is crucial if you're concerned about their cause. A proper diagnosis and treatment, if necessary, can prevent the recurrence of white spots.

As a nail technician or salon owner, staying updated on nail health is vital to providing excellent customer service and addressing clients' concerns regarding white spots on their nails. Encourage your clients to seek medical attention if needed and remind them to take preventive measures for maintaining healthy nails.

If you're interested in learning more about nail care and health, explore related content on our blog, subscribe to our newsletter, or share your thoughts in the comments section below. Let's work together to provide the best nail care experience for your clients!

By Tom Seymour

Reviewed by Judith Marcin, MD