Up to 7.5 million people in the United States have the autoimmune disease known as psoriasis. This condition causes your body to produce too many skin cells. Those 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 chest, arms, legs, trunk, and nails.
About half 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 part of the body that shows signs of psoriasis. Usually, people with psoriasis have the 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. How many pits there are 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 oncholysis. 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:
- a prescription steroid that you rub onto your nail or your doctor injects into the affected nail bed
- oral antifungal drugs to treat fungal infections caused by nail psoriasis
- phototherapy, which involves exposing areas affected by psoriasis to UV rays
- removal of the affected nail
Cosmetic treatments such as nail filing and polish can improve the appearance of your nails while they heal.
While you take medicine to treat your nail psoriasis, take special care to protect your nails at home.
- Keep your nails trimmed short so they won’t catch on anything and rip off.
- Wear cotton gloves whenever you’re working with your hands to protect your nails from injuries.
- Put on rubber gloves when you’re washing the dishes to protect your nails from soap.
- Avoid cleaning your nails with a nail brush or a sharp object. This will help prevent nail separation.
- Use moisturizers on your nails and cuticles, the dead skin at the base of your fingers. This can help prevent cracked or brittle nails.