Medically, they are called spoon nails. Koilonicia, a pitted nail that appears to spread out like a spoon. Nails do not grow straight, but curve inward. A common cause of spoon nails is iron deficiency anemia. Other possible causes include inflammatory skin diseases and genetic disorders.
In addition to appearing curved, spoon nails are thin, weak, and brittle. Spoon nails can affect fingernails, toenails, or both. Curved nails usually develop slowly over time. In rare cases, a newborn may be born with cholonikia.
Treatment for spoon nails varies depending on the underlying cause and may include iron supplements.
The name spoon nails comes from the fact that the nails are shaped like spoons. The curved marks may be perpendicular to the nail or horizontal. As the nail grows, the indentation gradually develops.
Not only will your nails appear pitted, but they may also feel brittle, weak, and thin.
Because spoon nails are often a sign of an underlying health condition or nutritional deficiency, they may also present symptoms associated with the condition or deficiency.
Spoon nails occur when your nails grow in a curved shape rather than a straight line.
The most common cause of spoon nails is iron deficiency anemia. This is when you have too little iron and cannot make enough red blood cells. About 5% of people with iron deficiency anemia experience spoon nails.
Researchers believe that low iron levels may lead to poor blood flow to the fingers and toes. This can cause the connective tissue underneath the nail bed (tissue that connects and supports the body) to weaken, resulting in spoon nails.
Iron deficiency is just one of the systemic conditions that can cause spoon nails. A systemic disease is a health condition that affects the entire body. Other systemic conditions that can cause spoon nails include:
- Nutritional deficiencies: In addition to iron, spoon nails can occur due to deficiencies in vitamin C, zinc, copper, selenium, cysteine, and other amino acids.
- Plummer-Vinson Syndrome (PVS): This is a rare condition that causes iron deficiency anemia with difficulty swallowing (dysphagia) due to the spider-like tissue in the esophagus. Approximately 37% to 50% of patients with PVS experience spoon nails.
- Hemochromatosis: This genetic disorder affects iron accumulation and causes spoon nails in 49% of cases.
- Endocrine disorders: People with hypothyroidism (hypothyroidism) develop spoon-shaped nails, slow nail growth, and make nails brittle. Diabetes can cause spoon nails due to nutritional deficiencies or damage to blood vessels.
- Autoimmune or autoimmune-related disorders: Spoon-shaped nails are rare but may occur in patients with systemic lupus erythematosus and Raynaud's disease.
- Professional Spoon Nail: Exposure to mineral oils (petroleum), organic solvents, or chemicals that cause skin irritation, contact dermatitis, or repetitive trauma (injury) can cause spoon nails.
Skin conditions are another major cause of spoon nails. Skin conditions that can cause spoon nails include:
- Lichen planus: This inflammatory skin disease causes the immune system to attack cells in the nails, skin, and mouth.
- Nail psoriasis: Psoriasis is an autoimmune disease that occurs when skin cells multiply too quickly. Sometimes psoriasis can affect the nails.
- Onychophytosis (20 nail dystrophy): This chronic condition of the nails causes rough, opaque nails.
- Onychomycosis: This is a fungal infection of the nail bed.
Anyone of any age can experience spoon nails. Some people are born with indentations. In 33% of neonatal cases, symptoms resolve spontaneously. Children who suck their thumbs or fingers may develop spoon nails. In rare cases, spoon nails may occur in families.
To determine if you have spoon nails, your healthcare provider will begin by performing a physical examination and reviewing your medical history. They will likely ask questions about your health history, family history, eating habits, and lifestyle factors.
A diagnostic test known as a droplet test may also be performed. To do this, drop water on the nail plate and see if the droplets collect on the nail.
They may also order blood tests, such as a complete blood count to check for anemia or a plate test to determine if iron supplements are needed.
There is nothing harmful about spoon nails themselves. However, the underlying cause of the nail may need to be treated.
The goal of treatment is to address the underlying cause and allow the nails to grow straight. If the underlying condition is not treated, the nail may become more spoonful. Once you treat the medical condition causing spoon nails, your nails will usually begin to grow normally.
The treatment plan depends on the underlying cause.
Many cases of spoon nails are associated with iron deficiency. If this is the cause, your doctor may recommend including iron-rich foods in your diet, such as beans, leafy greens, and fortified grains. You may need iron supplements.
Studies have shown that spoon nails in people treated for anemia typically heal within 4 to 6 months after starting iron supplements.
Spoon nails that affect the toenails can take up to a year and a half to go away because toenails take longer to grow.
Spoon nails are usually a symptom of another health condition. If you already have an underlying condition, there may be nothing you can do to prevent spoon nails from developing. Properly managing your underlying condition can help prevent spoon nails.
You can also prevent spoon nails by keeping your nails short and clean. Applying moisturizer or oil to your nails after showering may also help.
The most common cause of spoon nails is iron deficiency anemia. Over time, iron deficiency anemia can cause a number of health problems, including:
- heart disease: Severe iron deficiency puts stress on the heart and can cause fatigue, shortness of breath, and heart disease.
- infection: Iron deficiency affects the immune system's ability to fight infections.
- Developmental Delay: Pregnant women with iron deficiency have an increased risk of giving birth to a child with developmental delays.
- Pregnancy Complications: Pregnant women with iron deficiency are more likely to give birth prematurely or have a low birth weight baby.
- depression: Iron affects the balance of brain chemicals, and iron deficiency can lead to mood changes.
Spoon-shaped nails (coilonychia) are a condition that occurs when fingernails or toenails grow in a curved shape. Spoon nails appear spread out like a spoon. The middle part of the nail is lower than the outer edge. Spoon nails also feel weak, brittle, and thin. The most common cause of spoon nails is iron deficiency anemia. Other possible causes include inflammatory skin diseases, malnutrition, and autoimmune diseases.
Spoon nails themselves are not harmful, but the underlying condition may need to be treated. The goal of treatment is to manage the underlying condition so that the nail can grow and return to its normal shape. Many people with spoon nails need to take iron supplements daily.