Psoriasis is a chronic, inflammatory skin disease that causes scaly, raised patches on different body parts, including the knees, elbows, scalp, hands, and feet. Nail psoriasis is a subset of this autoimmune condition. It affects as many as 80% of people with psoriasis.
People with nail psoriasis won’t develop scaly patches on their nails, but distinct symptoms—like pitting and discoloration—can be a sign your nails are affected by psoriasis. Some people develop nail psoriasis several years after their initial psoriasis diagnosis, but others notice psoriasis symptoms on their nails first, without ever seeing any patches on their skin. Whenever it occurs, nail psoriasis can affect your quality of life.
The most common symptom of psoriasis is inflamed patches of skin that may look red, raised, thick, dry, or scaly. However, psoriasis affects the nails a bit differently. Symptoms of nail psoriasis include:
- Nail pitting: These are small indentations in the nail plate (the hard part of your nail). You may have one or several pits on affected nails.
- Hyperkeratosis: An overgrowth of cells can build up under the nail and cause a white, chalky substance to accumulate. This can cause a gap to form under the nail and can be painful.
- Discoloration: Nails may turn yellow or brown. Sometimes, they may develop an “oil drop” or “salmon patch,” a circular discoloration that looks like a brownish stain on the nail.
- Onycholysis: This is the separation of the nail plate from the nail bed (the soft skin and tissue beneath your nail plate).
- Onychomycosis: The nail can develop a fungal infection that causes it to become thicker than normal.
- Weakening or crumbling: Nails can become weak enough to break down and crumble.
What Causes Nail Psoriasis?
Most people with nail psoriasis have psoriatic inflammation, such as plaque psoriasis (skin cells multiply more rapidly and create discolored skin patches) or psoriatic arthritis (PsA), which causes joint and skin inflammation. Because psoriatic diseases cause the immune system to overproduce skin cells, any psoriatic inflammation can affect the nail bed or the skin around the nail, causing changes to its structure and appearance.
Some other autoimmune diseases, like rheumatoid arthritis (RA) and lupus, can be associated with nail changes that may resemble those seen in psoriatic arthritis. However, these conditions don't cause nail psoriasis.
Risk Factors
There are no risk factors specific only to nail psoriasis, but some things increase your risk of developing psoriasis or PsA—both of which often lead to nail psoriasis.
- Family history: Psoriatic diseases have a genetic component. They may run in families, meaning you're more likely to develop one if a parent, grandparent, brother, or sister has one.
- Certain medications: Some drugs—like beta-blockers, lithium, and certain antibiotics—are associated with an increased risk of developing psoriasis
- Stress: Stress is a risk factor for many autoimmune diseases, including psoriatic disease. Chronic stress can trigger an extreme inflammatory response and lead to symptom flares in people with existing psoriatic conditions.
- Infections: Psoriasis is caused by a heightened immune system response, so serious infections (especially strep throat) can trigger the initial symptoms.
- Skin injury: Physical injury to the skin, including severe sunburns, can trigger an overgrowth of skin cells during the healing process.
Nail psoriasis can affect the nail plate and the nail bed (skin and tissues beneath and around the nail plate). Diagnosing nail psoriasis usually includes a physical exam by a healthcare provider and additional testing to rule out other causes, like fungal infection.
Many skin conditions can cause similar changes to the nail plate and nail bed. Unless you have already been diagnosed with another type of psoriatic disease or show symptoms of a condition like psoriasis rash or joint inflammation, providers often can’t rely on a physical exam alone. Your provider may recommend procedures like the following:
- Dermatoscopy: Your provider uses a high-powered light and magnifying lens to examine your nails for signs of psoriasis versus other common nail infections or defects.
- Capillaroscopy: Similar to dermatoscopy, capillaroscopy is an up-close examination of the capillaries (small blood vessels) within the nail fold—the skin at the base of your nail. With simple tools, providers can magnify these capillaries and look for defects in appearance, which can help them diagnose psoriatic disease.
- Biopsy: Your provider might collect a biopsy (small skin sample) from the nail bed and send it to a laboratory for evaluation.
Nail Psoriasis Treatment
You can’t cure nail psoriasis or its inflammatory causes, but treatments can improve your symptoms. Most treatments for mild to moderate symptoms are topical and only applied to symptomatic areas. More severe symptoms are often treated systemically with medications that affect the immune system as a whole.
Topical
Steroid creams and vitamin-based treatments can be applied to mildly affected nails for several months at a time to treat symptoms like discoloration, pitting, build-up, and separation of the nail plate from the nail bed.
In moderate cases of nail psoriasis, your provider may recommend steroid injections under the nail or laser treatments to help improve your symptoms.
Systemic
Because nail psoriasis is part of inflammatory psoriatic disease, it can be treated—in more severe cases—with disease-modifying drugs like methotrexate. In some cases, biologics (drugs made in laboratories using living cells) can also be effective.
These drugs are taken orally or by injection. They're usually reserved for people experiencing skin or joint symptoms as well as nail symptoms.
Psoriasis is an autoimmune condition. If you have it, there may not be any way to prevent it from affecting your nails at some point. Factors like stress, illness, and injury can also trigger psoriasis, but it’s often not possible to prevent those things from happening.
However, you can take steps to reduce your symptoms and prevent symptom flares if you have psoriasis or nail psoriasis.Here are some ideas:
- Keep nails clean and dry to prevent build-up of dirt and germs under the nail
- Protect your nails from injury by wearing gloves when doing manual labor
- Keep nails moisturized with oil- or ointment-based creams and lotions
- Don’t pick at or bite your nails, nail beds, or cuticles, and don’t scrape under the nails to clean them with sharp tools
- Avoid intensive nail treatments, like acrylic or gel nails
Related Conditions
Nail psoriasis doesn’t typically lead to other health conditions, but psoriasis can. There are many possible comorbidities (conditions that occur with psoriasis), but the most common ones are:
- Psoriatic arthritis (PsA): PsA occurs in about 30% of people with psoriasis, causing joint pain, stiffness, and swelling. Nail involvement is a visible indicator to predict future joint inflammatory damages and disease activity.
- Heart disease: Chronic inflammation due to moderate to severe psoriasis can increase your risk of cardiovascular problems, including heart attack and stroke.
- Type 2 diabetes: Psoriasis increases a person’s risk of developing type 2 diabetes. This may be because psoriasis inflammation affects insulin resistance, the body’s ability to balance blood sugar levels.
- Obesity: Obesity can be a comorbidity or a trigger for psoriasis. It can result from other health conditions (like diabetes and heart disease) common in people with psoriasis or contribute to the heightened immune response that causes psoriasis.
Nail psoriasis won’t affect your life expectancy or cause other health conditions. However, if your nail psoriasis occurs in the context of another inflammatory disease, like psoriasis or psoriatic arthritis (PsA), it can affect your overall quality of life.
People with mild psoriasis and PsA don’t typically have a lower life expectancy. People with moderate to severe forms of both conditions may live a few years less on average. Early diagnosis, treatment, and management of your condition can help improve your life expectancy.
Having severe nail psoriasis can be painful, embarrassing, and frustrating. If you’re concerned about the physical appearance of your nails or experiencing discomfort, talk to your healthcare provider about treatments to help reduce symptoms, prevent flares, and slow down the progression of the condition.
Frequently Asked Questions
What's the difference between nail psoriasis and nail fungus?
Many nail fungus symptoms are similar to symptoms of nail psoriasis—including discoloration, thickening, and build-up under the nail. However, nail fungus is caused by an infection, not an autoimmune disease.
Fungal infections of the nail are more common in people with nail psoriasis, so it can be difficult to tell the difference.
What vitamin deficiency causes nail psoriasis?
Some studies suggest that low vitamin D levels are more common in people with psoriatic disease, but other studies haven't found a connection. It’s possible that a severe vitamin D deficiency could lead to nail psoriasis, but it’s not a commonly known cause.
If you have nail psoriasis, do you also have skin psoriasis?
Nail psoriasis is generally not a standalone condition—it’s caused by psoriasis or psoriatic arthritis. People might develop nail psoriasis before they develop skin or joint symptoms, so it's possible to have nail psoriasis without any visible skin psoriasis. However, nail psoriasis is a sign of an underlying inflammatory autoimmune disease.
