What Is Nail Pitting?

Medically reviewed by Casey Gallagher, MD

Nail pitting is the visual appearance of dents or dimples in your nail bed. Pitting occurs because something disrupts the normal nail formation. It's often related to autoimmune conditions like psoriatic arthritis (PsA).

Some conditions cause the nail pitting to appear differently. Treatment often depends on the underlying condition, but prevention of flare-ups may be possible.

Types of Nail Pitting

Nail pitting can be visibly concerning and is often a symptom of an underlying diagnosis. Many conditions, some more common than others, can cause these visual dents. 

Psoriasis

Psoriasis is an autoimmune condition that causes your skin cells to multiply rapidly. Skin cells are responsible for forming the nails on fingers and toes. Researchers do not understand what causes the immune system to become activated, but there does seem to be a link or trigger when skin is damaged. As a result, red, inflamed patches develop on the skin.

Nail pitting is common in psoriatic arthritis (PsA), an autoimmune condition that causes inflammation in joints and skin. PsA most often occurs in people who have psoriasis.

Alopecia Areata

Alopecia areata is another autoimmune condition. It occurs when your body attacks its hair follicles. People with this condition have round, irregular patches of hair loss. Alopecia areata typically affects hair follicles on the scalp and beard, but it can also affect nails.

Dyshidrotic Eczema

Dyshidrotic eczema is a condition that causes tiny blisters to form on your hands and feet. These blisters are usually highly itchy and develop after triggers like stress or shampoos and soaps. Chronic (long-term) dyshidrotic eczema can lead to nail pitting.

Reactive Arthritis

Reactive arthritis is an autoimmune disease that occurs a few days to weeks after a gastrointestinal or genitourinary tract infection (infection of your urinary or genital tract). Bacteria that reach your bloodstream trigger your immune system. This activates immune cells called cytotoxic T cells, which attack the lining of your joints or the synovium (the soft tissue that lines joints). Symptoms outside the joints are possible, and some people with this condition develop nail changes.

Sarcoidosis

Sarcoidosis is when your immune system overreacts and creates clusters of immune cells called granulomas. Granulomas typically form in the lungs, but they can grow in any organ. Nail changes in sarcoidosis aren't typical. When it does happen, it's usually because the condition has become systemic, meaning it affects your whole body.

Nail Pitting Symptoms

Nail pitting resembles small dents or deep lines that appear sunken on the nail's surface. It can affect fingernails and toenails. Nail pits and other nail symptoms can look different depending on the condition causing them.

Psoriasis Symptoms

Psoriasis causes thick patches of red skin with silvery-white scales. These patches tend to itch and usually appear on elbows, knees, scalp, hands, and feet. Nail pitting is common with psoriasis. The pits of psoriasis can appear:

• Small with well-defined boundaries

• Even in terms of size and depth

• Singular or multiple

• With red spots

Some people may also experience onycholysis, a condition that causes your nail plate to crumble and completely separate from the nail bed. Ten pits in one nail or more than 50 pits between all nails is often a clear sign of psoriasis.

Alopecia Areata Symptoms

People experiencing alopecia areata have round patches of irregular hair loss. Hair loss might occur in patches all over the scalp or around the sides and back of the head. You might experience complete head hair loss.

With alopecia areata, you might experience nail roughness and redness at the lunula (base of the nail bed).

Dyshidrotic Eczema Symptoms

The intensely itchy blisters of dyshidrotic eczema can last 3-4 weeks. While this condition can be life-long, some people may not redevelop blisters after the initial occurrence. The blisters form on the hands and feet and are not contagious.

People who experience dyshidrotic eczema for a long time may experience thick and discolored nails along with pit development.

Reactive Arthritis Symptoms

Symptoms of reactive arthritis depend on the body parts affected by the infection and might include:

• Difficulty urinating or a burning sensation during urination

• Eye discharge or conjunctivitis (pink eye)

• Abdominal pain and other gastrointestinal symptoms

• Stiff joints

Nail-related symptoms of reactive arthritis include:

• Pitting

• Onycholysis

• Nail dystrophy (distorted or discolored nails)

• Subungual keratosis (a build-up of skin cells under your nail bed)

Sarcoidosis Symptoms

Some people with sarcoidosis may not have any symptoms or may feel generally unwell. Symptoms depend on which organ or organs in your body the disease affects.

Nail changes with sarcoidosis include thickening, discoloration, onycholysis, brittleness, cracking, and pitting.

What Causes Nail Pitting?

Your nail plate is formed in a layer of cells called the nail matrix. Within the nail matrix are cells called keratinocytes. These keratinocytes undergo keratinization, a process that causes the cells to flatten out, creating the hard surface of the nail (the keratin). The nail matrix produces new keratin that collects on your nail plate, pushing it forward and causing the nail to grow. Keratinization creates the typical appearance of nails. Injury from trauma and inflammation from other conditions can disrupt this process.

In psoriasis, for example, your immune system attacks skin cells. The cells that create nails are also skin cells. If your body mistakes these skin cells for invaders and your immune system is activated, your body attacks the cells within the matrix. Your body then responds by creating more keratinocytes. These newly created cells are considered immature and do not function correctly. The nail continues to grow with damaged keratinocytes, resulting in the formation of pits.

How Is Nail Pitting Diagnosed?

Nail pitting is usually easily diagnosed by healthcare providers when they examine your nail beds. More than one condition can cause nail pitting, so healthcare providers may want to run other diagnostic tests based on your associated symptoms. They may perform tests such as:

• Nail clippings sample: A lab technician can view nail samples under a microscope. This test can help differentiate psoriasis from a nail fungal infection.

• Nail biopsy: A nail biopsy is the process of taking a small sample of the nail matrix. Although not always necessary, nail biopsies can help diagnose nail deformities caused by alopecia areata.

• Blood tests: Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) tests can help detect inflammation within the body. HLA-B27 is a blood test that can detect the genetic risk factor for reactive arthritis.

• Imaging test: If sarcoidosis is suspected, diagnostic procedures like chest X-rays and magnetic resonance imaging (MRI) scans can help look for lung scarring and inflammation.

Healthcare providers will review any other symptoms you are experiencing before deciding which tests to order. They will also need a thorough understanding of your health history, including your family history of autoimmune conditions.

Treatments for Nail Pitting

Effective treatment can help clear the nails' appearance and reduce any pain. Nail growth is a slow process. Symptom improvement can take up to six months or longer, and you may need to try a few treatment options before finding one that works.

Topical Medications

Medication applied directly to the skin, like corticosteroids, can help pitting. Dovenex (calcipotriol), made from vitamin D, can treat buildup under the nail. Tazorac (tazarotene), made from vitamin A, can treat pitting and other nail changes.

Intralesional Steroid Injection

This type of therapy involves injecting steroids directly into or near the lesions. Healthcare providers usually give these injections in a series every 4-6 weeks.

Systemic Medications

Systemic medications include biologics and disease-modifying antirheumatic drugs (DMARDs) like methotrexate. These types of medications help regulate your immune system. People with severe diseases usually benefit from them.

How To Prevent Nail Pitting

Prevention of the conditions that lead to nail pitting isn't always possible, but some measures can prevent flare-ups of this symptom. One way to prevent nail pitting is to take care of your nails and prevent injuries. When preventing nail pitting, try the following:

• Trim nails and keep them short to prevent snagging against surfaces

• If you tend to work with your hands, try wearing gloves to avoid injury

• Avoid pushing back the cuticles on the nail to prevent damage and infection

• Keep hands moisturized to prevent the surrounding skin from drying out

• Do not scrape underneath nails to prevent the nails from lifting from the bed

• Some nail polishes and light buffing are okay, but avoid artificial nails

Complications

The visual appearance of nail pitting can affect your quality of life. Pitting can also lead to changes in the nail that cause pain and affect activities of daily living, like grabbing items or even typing. Treating the underlying condition, like psoriasis or an infection of the nail bed, reduces the risk of more damage to the nail.

A Quick Review

Nail pitting is a symptom of an underlying condition like psoriasis or other conditions that affect your immune system. Healthcare providers can diagnose this symptom by observing its characteristics. They can also order other tests based on the symptoms associated with nail pitting.

If left untreated, the underlying condition can cause daily living complications. Nail pitting treatment involves topical and systemic medications as well as taking care of your nails and protecting them from injury.  

Frequently Asked Questions

Does stress lead to nail pitting?

If psoriasis is causing the pitting, stress can trigger flare-ups.

Which vitamin deficiencies can cause nail pitting?

Vitamins A, B, C, D, and E are important in nail health and can cause changes in the nail shape, possibly causing pitting.

Should I be worried about nail pitting?

Nail pitting is caused by an underlying condition. If left untreated, it can lead to pain and decreased quality of life. Reach out to a healthcare provider if you notice this symptom.

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