Koilonychia (Spoon Nails)

What is koilonychia?

Koilonychia refers to soft nails that have a spoon-shaped dent in them. Often these “spoon nails” form gradually. In many people, the first sign of koilonychia is flattened nails. Then, eventually, an indentation forms. The indentation is deep enough to hold a drop of water on your nail bed.

Usually, koilonychia occurs because of an underlying medical condition. You’re more likely to have spoon nails if you have nutritional deficiencies like iron or vitamin B deficiencies.

The name “koilonychia” comes from the Greek word koilos, which means hollow. Nychia refers to nail conditions.

Is koilonychia a fungal infection?

No. Koilonychia is a symptom, not an infection. But sometimes people with fungal nail infections can get spoon nails. Usually, if you have a fungal nail infection, you also have inflammation or irritation along with spoon nails.

What is the cause of koilonychia?

Most often, spoon nails are a sign of iron deficiency anemia. You may have an iron deficiency because you:

• Can’t absorb iron.
• Don’t consume enough iron.
• Have celiac disease, cancer or bleeding in your intestinal tract.
• Lose iron with excessive menstruation.

In some cases, koilonychia is hereditary. It can also result from an injury to the nail bed, such as thumb-sucking in babies and toddlers or too-tight shoes in people of all ages.

Sometimes, koilonychia points to another medical condition. Spoon nails can be a symptom of:

• Diabetes mellitus.
• Heart disease.
• Hemochromatosis (iron overload).
• Lichen planus.
• Lupus (systemic lupus erythematosus).
• Nail patella syndrome, a genetic disorder affecting your nails and bones.
• Psoriasis.
• Underactive thyroid (hypothyroidism).
• Raynaud’s phenomenon.

Are spoon nails always a symptom of an underlying disease?

No. You may have spoon nails because of an injury or overexposure to petroleum products. For example, hairstylists may use petroleum products routinely for certain hair treatments.

Sometimes, spoon nails are genetic. And people living at very high altitudes appear to have a higher likelihood of spoon nails.

Who is most likely to have koilonychia?

You’re more likely to have koilonychia if you eat a vegetarian diet, which may raise your risk of being low in iron. Other risk factors include having:

• Iron deficiency.
• Low blood flow to your fingers or toes.
• Lupus (systemic lupus erythematosus).
• Malnutrition or an eating disorder.

How is koilonychia treated?

Healthcare providers treat the underlying cause of koilonychia. If you have an iron deficiency, changing your diet or taking supplements may correct and prevent spoon nails.

For example, you may eat more iron-rich foods, such as:

• Beans and lentils.
• Dark chocolate.
• Fortified foods, such as bread or breakfast cereal.
• Iron-rich fruit, such as dates, figs, prunes and raisins.
• Leafy greens, such as spinach or kale.
• Meat and seafood rich in iron.
• Nuts and seeds.
• Tofu.

You may also need iron supplements. Your healthcare provider can help you determine if you need to take a supplement or make diet changes.

Is koilonychia reversible?

Yes. Often, treating the underlying cause of koilonychia will make your nails grow properly. But it can take a long time. It may take six to 18 months for koilonychia to go away.

How can I prevent spoon nails?

There’s no guaranteed way to prevent spoon nails. You can lower your risk of spoon nails by eating a balanced diet. If you have a medical condition that could cause spoon nails, speak with your healthcare provider about management.

You can also lower your risk of nail problems by taking care of your nails. You should:

• Clean your nails with a soft brush.
• Keep your nails moisturized with hand cream.
• Trim your toenails straight across to prevent ingrown nails.
• Use rubber gloves when cleaning or using chemical products.
• Wear properly fitting footwear that doesn’t cramp your feet.

When should koilonychia be treated by a healthcare provider?

If you have koilonychia, you should see your healthcare provider. Sometimes, koilonychia is not a cause for concern. But often, it points to a nutrient deficiency or medical condition.

Your healthcare provider can give you tests to determine the underlying cause of spoon nails. Your healthcare provider can also provide treatment options for any underlying conditions.

Can babies have spoon nails?

Yes. Spoon nails in babies are fairly common. One study found that nearly 1 in 3 infants have spoon nails. Usually, babies’ nails flatten as they grow.

A note from Cleveland Clinic

Koilonychia is when your nails have an indented shape, like a spoon. Often, spoon nails are a sign of iron deficiency. You’re also more likely to have spoon nails if you have an autoimmune disease, such as lupus, or poor blood flow to your hands or feet. For many people, spoon nails go away if you treat the underlying cause. Your healthcare provider may also recommend dietary changes or supplements to treat spoon nails.