Nail depressions are often found in people with psoriasis, but they can be a sign of several other conditions. People with nail pitting may want to see a doctor to discover the underlying cause.
In this article, we look at the signs of nail pitting, the potential causes, and what forms of treatment are available.
Signs and symptoms
Nail pitting most commonly develops on the fingernails, although it may occur on the toenails.
People with nail pitting will notice small pits developing on the surface of the nail on either their fingers or toes. Fingernails are more commonly affected than toenails, although it is unclear why.
There can be one single pit or many pits. A nail with multiple pits can look like the surface of a thimble.
The nail is part of the skin and grows from the nail root, which is found just under the cuticle. This origin is why nail pitting is often related to a skin condition.
Causes and related conditions
Nail pitting is often a sign of another condition that can include:
- psoriasis, which causes skin inflammation
- eczema, a long-term skin condition that makes the skin red, itchy, and cracked
- reactive arthritis or inflammation caused by an infection elsewhere
- alopecia areata, which causes temporary bald patches on the scalp
Psoriasis is a common skin condition that causes inflammation of the skin and often leads to patches of red, scaly skin.
People who develop psoriasis tend to have flare-ups throughout their lives. The frequency of these flare-ups varies from person to person.
The severity of psoriasis can also vary greatly, from small patches that are barely noticeable to larger patches across the body.
Psoriasis is not caused by infection, it cannot be passed on to other people, and it does not develop into cancer.
The National Psoriasis Foundation state that while it can develop at any time, psoriasis most commonly starts in people aged between 15 and 35. Around 1.5 percent of African-Americans have psoriasis, compared with 3.6 percent of Caucasian Americans.
Around half the people who have psoriasis will also notice changes in their nails.
Psoriatic nail disease
There are several nail changes that can occur with psoriasis, including:
- Pitting, when either one pit or many pits appear on the surface of the nail.
- Onycholysis, when the nail separates from the skin. This begins as a white or yellow patch at the top of the nail that works its way down to the base. The skin underneath can become infected, as a result.
- Subungual hyperkeratosis, when a chalk-like material builds up under the nail, often making the nail raised and tender.
- Color changes, when nails become yellow or brown.
- Fungal nail infection, which can make the nail thicker.
Around 4 in every 5 people with psoriatic arthritis will also notice nail changes.
Diagnosis and when to see a doctor
A biopsy may be required to diagnose the cause of nail pitting.
Anyone concerned with pits on their nails should see a doctor. Typically, the first thing the doctor will do is a physical examination.
A look at someone's medical history may also help, especially if they have had psoriasis or other conditions linked with nail pitting.
The appearance alone of someone's nails will often be enough for a doctor to diagnose the problem, particularly if it is psoriatic nail disease.
Occasionally, a doctor will send a sample of the nail for a biopsy to help confirm the diagnosis. A biopsy is a medical procedure that examines tissue under a microscope to see if there are any cell abnormalities.
Cases of nail psoriasis can be difficult to diagnose unless the person presents skin psoriatic lesions, as well. Only around 5 to 10 percent of people with nail psoriasis will not have psoriasis or psoriatic arthritis also.
Nail pitting can be mild. If the pitting is not causing any discomfort, it will not require any treatment. More severe cases can cause discomfort and distress, however.
Nail pitting is quite difficult to treat, although some modern methods have been shown to be effective.
Treatments that can be applied to the nail include steroids, salicylic acid, calcipotriol, and tazarotene, although these are often not very effective. It is important to remember that nails grow slowly and this type of remedy only treats the new nail growing, not the existing one.
A skin specialist may also suggest one of the following:
- Antifungal treatment: This might be needed if there is also a fungal infection.
- Steroid injected into the nail: This treatment can be painful.
- Removing the nail: Nails can be removed either by using an ointment that takes 7 days to work, or surgically with a local anesthetic.
In severe cases, such as when a person is not able to use their hand or walk properly if pitting is on their toes, more powerful drugs can be used to suppress inflammation. These will only ever be prescribed by a doctor.
Wearing gloves when performing manual labor will protect the hands and nails.
Before undergoing treatment, people with nail pitting should first consider the self-management steps they can take to care for their nails, such as:
- keeping toenails and fingernails short
- keeping nails dry
- protecting nails from damage by wearing gloves when doing manual work, for example
- avoiding manicures at the base of the nail as they may cause infection
- avoiding wearing false nails
- avoiding using nail varnish containing acetone, as it can damage the nail
- wearing comfortable shoes that give space for the toes to move
People should also avoid cleaning their nails with a sharp object or brush. It is better to soak the nails in warm water to remove debris.
Nail pitting can be difficult to treat. However, if the condition is mild and not causing discomfort, then people can lead a normal life.
If someone is worried about how the pits on their nails look, they may be able to cover them with a nail varnish that does not contain acetone.
In more severe cases, pitting can continue to cause discomfort and the appearance of the nails may cause a person distress. It can also affect the functionality of the hands and feet.
In the case of nail psoriasis, pitting is a marker for more severe skin symptoms and joint involvement. If these develop, diagnosis and treatment will need to be sought.
When skin lesions are not present, nail psoriasis can also aid the diagnosis of cases of psoriatic arthritis.
While treatment for nail psoriasis is long-term and often ineffective, it is improving greatly over time. Following the simple management tips can also help with nail pitting, and improve a person's quality of life.