Psoriasis is an inflammatory autoimmune disease that usually causes your body to produce too many skin cells, which can form thick, itchy, scaly patches on the skin. It can also affect your joints and the appearance and texture of your nails — fingernails more often than toenails.

Psoriasis can occur anywhere on the skin, but is typically found on the:

  • elbows
  • knees
  • lower back
  • scalp

Around 7.4 million people in the United States have psoriasis. Up to 82 percent of people with psoriasis may experience nail changes. And around 80 percent of people with psoriatic arthritis, a related joint condition, develop nail changes as well. Doctors aren’t sure why this happens to some people and not others.

In rare cases, the nails are the only parts of the body that show signs of psoriasis. But usually, people with psoriasis have a rash on other parts of their body as well.

Nail psoriasis can look different in each person. Symptoms may range from mild to severe.

Pitting

The nail plate is the hard surface that sits over the nail bed. It’s made of keratin, which is a hardened protein found in skin and hair cells.

Nail psoriasis causes your nail plate to lose cells. This results in small pits forming on your fingernails or toenails, which may look like your nails were hit with the tip of a pen. The number of pits varies from person to person.

Some people may have only a single pit on each nail, while others have dozens of pits. The pits can be shallow or deep.

Changes in nail shape or thickness

In addition to pitting, weakness of the structures that support nails can cause your nails to crumble. Nails can also become thicker due to a fungal infection called onychomycosis, which is common in people with psoriasis.

Additionally, your nail may get thicker because it develops a chalky substance underneath. When this happens, it’s called subungual hyperkeratosis and may be painful or uncomfortable.

Nail bed separation

Sometimes your nail can separate from the nail bed, which is the skin underneath the nail plate. This separation is called onycholysis. It leaves an empty space under your nail.

If you have nail psoriasis, you may first notice a yellow discoloration at the tip of a nail. The color and lifting of the nail may eventually go all the way down to the cuticle.

Bacteria can get into the space under the nail and cause infection, which can turn the whole nail a dark color.

Discolored nails

The color of your nail may also change. You might see a yellow-red patch in the nail bed. It looks like a drop of oil under your nail plate, which is where it gets its name: oil-drop spot.

A more severe case of psoriasis may also cause the lunula — the small, half-moon shape that appears at the bottom of your nail — to look red. This is caused by dilated blood vessels.

You may also notice very narrow, reddish-purple lines on your nails. These are called splinter hemorrhages.

Additionally, your toenails or fingernails can turn a yellow-brown color. Crumbling nails often turn white.

Blood spots

You also might develop blood spots under your nail, which are called splinter hemorrhages. These deposits are narrow and several millimeters long.

Rough nails

One or all your nails may look like sandpaper, notes Morgan McCarty, DO, a dermatologist at Austin Regional Clinic in Round Rock, Texas. This rare condition is called trachyonychia.

Dermatologists typically treat nail psoriasis with the same treatments that are used for psoriasis. The treatment that’s best for you depends on several factors.

For example, McCarty considers each person’s age and the number of nails that are affected. She also works with a rheumatologist to check for psoriatic arthritis.

Nail psoriasis can be tough to treat and treatments take time to work. As McCarty points out, it can take 4 to 12 months to see improvement in your nails for any treatment.

Many helpful treatments are available, including:

Topical medications

Dermatologists may suggest an over-the-counter or prescription topical medication. You apply topical medications directly to your nail once or twice per day.

Topical medications for nail psoriasis come in various forms, such as:

  • ointments
  • creams
  • emulsions
  • nail polishes

Topical corticosteroids, including clobetasol propionate and betamethasone dipropionate, can provide mild improvement of some psoriasis symptoms.

Topical treatments with vitamin D help reduce inflammation and slow excess skin cell production. They can relieve nail thickness by reducing cell buildup under the nails.

Vitamin D topical treatments include:

  • calcipotriol (Calcitreme)
  • calcipotriene (Dovonex)
  • calcitriol

Tazarotene (Tazorac) is a topical retinoid, a medication made from vitamin A. It can help with:

  • nail discoloration
  • pitting
  • separation

Anthralin is an anti-inflammatory ointment that slows excess skin cell production. When applied to the nail bed once daily, it improves symptoms like thickening and onycholysis — although it may temporarily discolor nails.

Corticosteroid injections

In some cases, a dermatologist may inject a corticosteroid into or near your nail. Corticosteroid injections can treat symptoms such as:

  • nail thickening
  • ridges
  • separation

Oral drugs

If a topical medicine doesn’t work or symptoms are more severe, “an oral prescription medicine is usually the next line of defense,” says McCarty.

Dermatologists also advise oral therapies when:

  • Psoriasis affects more than three nails.
  • The condition greatly impacts a person’s quality of life.
  • More than 10 percent of an individual’s body surface is covered in psoriasis or affected by psoriatic arthritis.

Because many oral medications can have some side effects, it’s important to talk with your doctor about what you should expect if you start taking one.

Systemic (body-wide) drugs work throughout your body to clear both the skin and nails in moderate-to-severe psoriasis. These drugs are available as a liquid, pill, or injection.

Systemic drugs include:

When psoriasis hasn’t responded to other treatments, biologic drugs may be a good option. Biologics are a class of newer medications that target the specific part of the immune system that is overactive due to psoriasis.

Biologics include:

  • adalimumab (Humira)
  • etanercept (Enbrel)
  • infliximab (Remicade)
  • ustekinumab (Stelara)
  • secukinumab (Cosentryx)
  • risankizumab (Skyrizi)

You receive biologic drugs by infusion or injection. Many times, the injection can be performed at home.

Because biologics suppress the immune system, taking one may make you more susceptible to infection. Talk with your doctor about what you can expect if you decide to take a biologic.

Oral antifungal drugs treat fungal infections caused by nail psoriasis.

Phototherapy

Phototherapy improves nail separation and discoloration by slowing the growth of skin cells. For nail psoriasis, the treatment is called PUVA.

PUVA exposes areas of skin affected by psoriasis to:

  • ultraviolet (UV) rays from the sun
  • a phototherapy unit at a clinic or at home
  • a laser

First, you soak your hands in a medication called psoralen or take it by mouth. Psoralen makes your skin sensitive to UVA light. After the medicine, you’re exposed to UVA light.

Laser treatment

Laser therapy for nail psoriasis uses the pulsed dye laser. It works by targeting blood vessels under the skin with a beam of light.

Laser therapy is most helpful for nail splitting and subungual hyperkeratosis, says McCarty.

Home treatments

A few natural remedies that are said to relieve psoriasis symptoms include:

  • turmeric
  • Dead Sea salt
  • aloe vera

However, there isn’t enough scientific evidence to prove any of these alternative treatments actually work.

When it comes to nail psoriasis specifically, alternative treatment options are very limited.

One herbal remedy that may help nail psoriasis is indigo naturalis, a Chinese herbal medicine that comes from the same plant used to make blue dye.

In one small study from 2015, an indigo naturalis extract in oil (Lindioil) improved nail thickening and onycholysis better than topical calcipotriol.

Because of the lack of research around this herbal medicine and most other home remedies for nail psoriasis, it’s best to discuss treatment options with your doctor before deciding on a course of action.

To prevent nail psoriasis flares, consider trying these tips:

  • Keep your nails short to avoid injury or lifting of the nail from its bed. Trimming your nails regularly will also help prevent buildup from collecting underneath them.
  • Avoid biting or picking at your nails and pushing back your cuticles. Injuries to the skin can set off psoriasis flares. This is called the Koebner phenomenon.
  • Wear gloves when gardening, washing dishes, or doing any kind of work in water. For the best protection, wear cotton gloves under vinyl or nitrile gloves.
  • Keep your nails clean and dry to prevent infection.
  • Use a moisturizing cream on your nails and cuticles. This can help prevent cracked or brittle nails.
  • Avoid cleaning your nails with a nail brush or sharp object. This will help prevent nail separation.
  • If you smoke, try to quit. Smoking can increase the risk of psoriasis
  • If you drink, try to do so in moderation, as alcohol is also associated with a higher risk of psoriasis.

If you feel self-conscious about your nails, you can alter their appearance by gently filing and buffing them and by applying polish.

Avoid fake nails, which increase the risk of your nail separating from its bed.

The National Psoriasis Foundation recommends that everyone with psoriasis connect with a dermatologist for diagnosis and treatment. If you’ve already received a diagnosis, make an appointment with your doctor if:

  • Your symptoms are getting worse or are bothering you.
  • The treatment you’re using isn’t helping.
  • You want to try a new therapy or alternative remedy.

Psoriasis is a common skin condition that can cause nail changes in some people. If you’ve received a psoriasis diagnosis with psoriasis and notice your nails are looking brittle or pitted, talk with your doctor about treatment options.

A variety of treatments are available for nail psoriasis, and the right one for you will depend on a few factors, including the severity of your condition.