The extra cells build up on your skin, forming scaly red or silvery white patches, sores, or blisters. Psoriasis can occur anywhere on your body, including your:
About 35 percent of people with psoriasis and around 80 percent of people with psoriatic arthritis, a related joint condition, develop nail changes. 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. Usually, people with psoriasis have a rash on other parts of their body as well.
Nail psoriasis can cause several different symptoms.
The nail plate is the hard surface that forms the top of your nails. It’s made of keratin cells.
Nail psoriasis causes your nail plate to lose cells. This results in small pits forming on your fingernails or toenails. 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.
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 white or yellow patch at the tip of a nail. The color will 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.
Changes in nail shape or thickness
In addition to pitting, you might notice other changes in the texture of your nails. Psoriasis can cause lines called Beau’s lines to form across your nails.
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.
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.
Your toenails or fingernails can also turn a yellow-brown color. Crumbling nails often turn white.
Nail psoriasis can be hard to treat because psoriasis affects the nail as it grows. Treatment options include:
Topical corticosteroids are a common nail psoriasis treatment. They’re available as:
- nail polishes
You’ll typically apply them once or twice a day.
Corticosteroid injections can be helpful for treating symptoms like:
- nail thickening
Calcipotriol (Calcitreme), calcipotriene (Dovonex), and calcitriol are man-made versions of vitamin D.
They help reduce inflammation and slow excess skin cell production. These medications can relieve nail thickness by reducing cell buildup under the nails.
Tazarotene (Tazorac) is a topical retinoid, a medication made from vitamin A. It can help with:
- nail discoloration
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.
Moisturizers don’t treat nail psoriasis, but they can relieve itching and redness and help the skin around your nails heal.
Systemic (body-wide) drugs like cyclosporine, methotrexate, apremilast (Otezla), and retinoids are available as a liquid or pill or an injectable medication.
They work throughout the body to clear both the skin and nails and are meant for moderate-to-severe psoriasis.
Biologic drugs like adalimumab (Humira), etanercept (Enbrel), and infliximab (Remicade) dampen the overactive immune response that causes psoriasis.
You receive these drugs by infusion or injection. They’re typically reserved for psoriasis that hasn’t responded to other treatments.
Oral anti-fungal drugs treat fungal infections caused by nail psoriasis.
Phototherapy 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
The light slows the growth of skin cells.
For nail psoriasis, the treatment is called PUVA. First, you soak your hands or take a medication called psoralen. Then, you’re exposed to UVA light. This treatment can be helpful for treating nail separation and discoloration.
Laser therapy may be helpful for nail psoriasis. The type of laser used in nail psoriasis is called the pulsed dye laser (PDL).
It works by targeting blood vessels under the skin with a beam of light, and it appears to reduce the severity of nail psoriasis.
A few natural remedies may relieve psoriasis symptoms, including:
- Dead Sea salt
- aloe vera
But, for nail psoriasis, the alternative treatment options are more limited.
One herbal remedy that’s shown benefit for nail psoriasis is indigo naturalis, a Chinese herbal medicine that comes from the same plant used to make blue dye.
In one small study, an indigo naturalis extract in oil (Lindioil) improved nail thickening and onycholysis better than calicootriene.
In addition to medication, try these tips for preventing flares:
- Keep your nails short to avoid injury or lifting the nail off of its bed. Trimming your nails regularly will also prevent buildup from collecting underneath them.
- Don’t bite or pick at your nails or push back your cuticles. Injuries to the skin can set off psoriasis flares. This is called the Koebner phenomenon.
- Wear protective gloves when you garden or play sports and when you wash dishes or work with your hands in water.
- Keep your nails clean 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 a sharp object. This will help prevent nail separation.
If you feel self-conscious about your nail psoriasis, there are some things you can do to make it less noticeable.
Cosmetic treatments such as nail filing, buffing, and polish can improve the appearance of your nails while they heal. Just avoid fake nails, which may increase the risk of your nail separating from its bed.
The National Psoriasis Foundation recommends that everyone with psoriasis see a dermatologist for a diagnosis and treatment. If you’ve already been diagnosed, make an appointment with your doctor if:
- your symptoms are getting worse or are bothering you
- the treatment you’re on isn’t helping
- you want to try a new therapy or alternative remedy