Psoriatic Arthritis

Medically Reviewed by Zilpah Sheikh, MD on April 27, 2024
Written by Leah Rosenbaum, Amy Gopal
11 min read

Psoriatic arthritis (PsA) is a form of inflammatory arthritis. It affects about 1.5 million people in the U.S., or 30% of people who have psoriasis. Psoriasis is a skin disease that causes a red, scaly rash, most often on your elbows, knees, ankles, feet, and hands.

PsA is an autoimmune condition. It happens when your body’s immune system attacks healthy tissue by mistake. PsA most often affects your skin and your joints, which can become swollen, stiff, and painful. Over time, if you don’t treat it, the inflammation can damage joints and tissues.

The symptoms of psoriatic arthritis include:

  • Swollen fingers and toes
  • Foot pain
  • Lower back pain
  • Fatigue
  • Swelling and pain around tendons
  • Stiffness and tiredness in the morning
  • Less range of motion
  • Nail changes
  • Eye redness and pain
  • Scaly skin, especially on your knees, elbows, and scalp

Where can psoriatic arthritis affect your body?

This condition can involve different body parts.

Spondylitis affects your spine and may cause inflammation and stiffness in your neck, lower back, spinal vertebrae, or sacroiliac region (pelvic area), which can make it hard to move. Spondylitis also can attack connective tissue, such as ligaments, or cause arthritis in the joints of your arms, hips, legs, or feet.

Enthesitis is inflammation of the entheses, the areas where ligaments or tendons insert into your bones. You’re likely to get it on the bottoms of your feet, your Achilles tendons, and the places where ligaments attach to your ribs, spine, and pelvis. It affects only people with PsA, not those with other types of arthritis such as rheumatoid arthritis or osteoarthritis. Over time, enthesitis can make tissues in the affected area ropey (your doctor will call this fibrosis) or solid (the doctor might refer to this as ossification or calcification).

Dactylitis, or “sausage digits,” is inflammation that affects an entire finger or toe. It happens when small joints and entheses of the surrounding tendons get inflamed. Dactylitis is another hallmark of psoriatic arthritis. It usually involves a few fingers or toes, but not in a symmetrical pattern. Unlike other types of arthritis, PsA can affect different toes and fingers on different sides of your body.

What are the early warning signs of psoriatic arthritis?

Most people may have already had psoriasis for 10-20 years before developing psoriatic arthritis. But for some people, joint pain can start at the same time as skin problems, or even before psoriasis appears. At the beginning stages of the disease, it can be normal to have periods when symptoms feel worse, and then periods when symptoms seem to improve.

Early warning signs of psoriatic arthritis may include:

  • Joint pain and swelling
  • Feeling stiff
  • Fatigue
  • Changes to your nails
  • Small or large patches of psoriasis on your body

Psoriatic arthritis nails

Up to 80% of people with psoriatic arthritis see changes to their fingernails and toenails. This is known as a separate condition, called nail psoriasis. Nails can experience many types of changes due to psoriatic arthritis. Some of these include:

Nail pitting. These are small dents in the nail plate. It's the most common symptom of nail psoriasis.

Nail crumbling. Nails might also become thin or brittle.

Beau’s lines. These are horizontal lines and grooves that run across the nail plate.

Discoloration. Parts of the skin underneath your nails could change to colors such as yellow, brown, pink, or red. These are called oil drop spots or salmon patches.

Splinter hemorrhages. Small lines of blood can appear under the nail.

Onycholysis. This is when the nail separates from the nail bed.

Subungual hyperkeratosis. This is a thickening of the nail bed.

Infection. Your nails might become infected with a fungus.

Psoriatic arthritis rash

If you have psoriatic arthritis, you may also have the rash that comes with having psoriasis. This rash usually looks like scaly patches, and it can be itchy. The rash is most commonly found on the knees, elbows, torso, and scalp, but it can be found on other parts of the body as well. There are several different types of psoriasis, each with different rashes:

Plaque psoriasis. This is the most common type of psoriasis, and it causes scaly, raised skin patches.

Guttate psoriasis. You may see small, red dots on your torso or limbs after an infection, like strep throat. It's more common in children and young adults.

Pustular psoriasis. It causes pus-filled bumps, surrounded by red skin.

Inverse psoriasis. You may have smooth, red patches in between folds of skin, like beneath your breasts.

Erythrodermic psoriasis. In this rare and serious type of psoriasis, a red, scaly rash covers most of your body.

Like other types of arthritis, psoriatic arthritis can be more or less severe. Some doctors group psoriatic arthritis based on what joints it affects or what side of your body experiences symptoms. Based on this, there are five types of psoriatic arthritis:

Distal interphalangeal predominant psoriatic arthritis. This type affects the joints near your fingers and toes. It’s the type most likely to have nail psoriasis.

Symmetric polyarthritis. This is when more than five joints are affected, and the same joints on both sides of your body are impacted. For example, both of your ankles, shoulders, and elbows.

Asymmetric oligoarticular psoriatic arthritis. This is when two to four joints on both sides of your body are affected. For example, one ankle and one shoulder.

Spondylitis. This is when the joints between your spine's vertebrae (back bones) are affected. It can also affect your lower back.

Arthritis mutilans. It's the rarest type of psoriatic arthritis that causes severe inflammation in your hands and feet. It also causes bone loss and deforms your joints.

Doctors aren’t sure what causes psoriatic arthritis, but these things may play a role:

Genes. Having a parent with psoriasis increases your chance of getting psoriasis and makes you more likely to have psoriatic arthritis. Scientists have identified some genes that they believe play a role in psoriatic arthritis.

Infection. An infection that sets off your immune system could be to blame. Psoriasis, for example, is often triggered by strep throat.

Physical trauma. Studies show that some people who already have psoriasis and experience trauma to their bone or joint may be more likely to develop psoriatic arthritis.

 

Psoriasis. Up to 30% of people with psoriasis get psoriatic arthritis. People who have more severe psoriasis may be more likely to get psoriatic arthritis, but this isn't always the case and needs further research. It affects men and women equally.

Age. You can get PsA at any age, but it usually affects people between 30 and 50.

Family history. As many as 40% of people with psoriatic arthritis have a family history of skin or joint disease.

Obesity. Studies show that obesity is a risk factor for both psoriasis and psoriatic arthritis.

To diagnose PsA, your doctor will ask about your symptoms and whether any of your relatives have psoriasis, psoriatic arthritis, or another autoimmune disease. They’ll also check how well your joints move and whether you have pain, tenderness, swelling, or warmth. You may have tests including:

  • Imaging tests such as X-rays, MRIs, CT scans, and ultrasounds
  • Blood tests to rule out other kinds of arthritis and look for signs of inflammation
  • Tests of the fluid from your joints or tiny samples of skin

Psoriatic arthritis vs. rheumatoid arthritis

Psoriatic arthritis shares some symptoms with rheumatoid arthritis (RA), such as joint pain and swelling. But RA usually affects joints on both sides of your body, while this is not always the case with psoriatic arthritis. Psoriatic arthritis also typically affects fewer joints than RA.

People with RA may have bumps under their skin close to their joints, called rheumatoid nodules. This doesn’t tend to happen with psoriatic arthritis. But other skin and nail changes are more likely with psoriatic arthritis than with RA.

Finally, people with psoriatic arthritis won't have the common antibodies that many people with RA have.

Psoriatic arthritis radiology

Your doctor may want to do radiology tests, such as an MRI, CT scan, ultrasound, or X-ray, to help diagnose psoriatic arthritis. Sometimes, it can be hard to see evidence of psoriatic arthritis on these images if you are still in the early stages of the disease. In later stages of the disease, radiographic findings of PsA may include:

  • Narrowing of the spaces between joints
  • Erosions of the joints
  • The formation of bone spurs
  • Damage to the bone, in severe cases

Medical treatments for psoriatic arthritis include:

Nonsteroidal anti-inflammatory drugs (NSAIDs). These are over-the-counter medications such as ibuprofen and naproxen.

Disease-modifying antirheumatic drugs (DMARDs). These can slow or stop pain, swelling, and joint and tissue damage. If NSAIDs don’t work, your doctor will try DMARDs. They may take longer to work.

Immunosuppressants. If you can’t take a DMARD, you might get a type of drug called an immunosuppressant. These drugs curb your immune system, which is what’s causing the problem in an autoimmune condition such as PsA. But they can also make it more likely that you’ll get an infection.

Biologics. If immune suppression doesn't work, your doctor may prescribe a biologic. These are a newer type of DMARD. Instead of weakening your entire immune system, these medications block a protein that causes inflammation.

Enzyme inhibitor. This works by blocking a certain enzyme, a kind of protein, called PDE-4. That helps slow other reactions that lead to inflammation.

Steroids. These can help control inflammation, but doctors don’t use them often for PsA. That's because they can make your skin rash worse. Doctors prescribe steroids only when you really need them. If you use them for a long time, you could have serious side effects such as brittle bones, weight gain, hypertension, and diabetes.

Surgery. A severely damaged joint can be replaced with a new one made from metal and plastic.

You can ease some psoriatic arthritis symptoms on your own. Try to:

Keep a healthy weight. Carrying extra pounds puts more stress on your joints. It may also affect how well your medications work.

Stop smoking. This is one of the best things you can do for your overall health.

Limit alcohol. It can also affect how your treatments work.

Exercise. It’s a great way to protect your joints and keep your weight in check. Stronger muscles can also support your joints. Low-impact exercises, such as swimming or walking, are easier on them. Ask your doctor about an exercise plan.

Use physical or occupational therapy. Your doctor might recommend that you see a specialist who can help you learn to manage your symptoms. This can involve exercises, body adjustments, hot and cold therapy, and tips for changing the way you do certain things. A physical or occupational therapist can also help you pick assistive devices such as braces or splints to support your joints.

Use acupuncture or massage therapy. These treatments are natural ways to ease pain and stiffness.

Use hot and cold therapy. Heating pads or sitting in a hot bath can help painful joints. An ice pack can help ease inflammation and pain. You may want to switch between heat and cold therapy depending on how you feel.

Take vitamins. Some vitamins and minerals, such as calcium and Vitamin D, may help slow bone deformation.

Use tools that help your joints. Tools are available to help open cans, pick up heavy objects, lift objects off the ground, and more. Using these tools when needed can help protect your joints from unnecessary stress.

Rest when needed. Living with a chronic illness such as psoriatic arthritis can be painful and exhausting. Make sure you take enough time to rest throughout the day. 

Psoriatic arthritis diet

There's no one specific diet recommended for people with psoriatic arthritis. The best diet to eat is one that will help you eat nutritious food and keep you at a healthy weight. To reduce the chances of a flare-up, you may also want to eat anti-inflammatory foods, such as:

  • Foods high in omega-3 fatty acids, such as salmon, chia seeds, and walnuts
  • Foods high in antioxidants, such as berries, spinach, and tea
  • Foods on the Mediterranean diet, including whole grains, fruits, and vegetables

You may want to avoid foods that can commonly trigger inflammation. These include:

  • Alcohol
  • Dairy
  • White bread, rice, and pasta
  • Fast food
  • Red meat
  • Foods high in added sugar, such as juice and candy
  • Gluten

Is psoriatic arthritis a disability?

Depending on severity, psoriatic arthritis can be a disabling disease. Psoriatic arthritis is one of the conditions named under the Listing of Impairments according to the Social Security Administration. You could qualify for Social Security benefits if you apply for them and are deemed disabled.

Just like all people with disabilities, people who are disabled from psoriatic arthritis are also protected under the Americans with Disabilities Act, or ADA. The ADA prevents discrimination against people with disabilities in areas including transportation, public accommodations, schools, government services, and employment.

If your psoriatic arthritis makes it difficult to work, you can request reasonable accommodations from your employer or your school under the ADA. Some of these accommodations could include:

  • Supplying grip aids if you need to grip pens or pencils
  • Providing an ergonomic chair that is more comfortable for your joints
  • Providing extra time to complete paperwork or schoolwork
  • Organizing items in a way that minimizes the need to do heavy lifting
  • Having rest breaks where you can stretch your joints
  • Working from home on days when you are in pain

PsA can make you more likely to have:

  • A form of arthritis called gout
  • Fatigue
  • Obesity
  • Diabetes
  • Anemia
  • Metabolic syndrome, which may include high blood pressure, high cholesterol, and high blood sugar
  • Fibromyalgia
  • Depression and anxiety

Certain things could trigger psoriatic arthritis, including:

Psoriatic arthritis is a form of inflammatory arthritis that primarily affects people who have psoriasis. It can cause painful joint swelling and stiffness, along with nail damage and a psoriasis rash. There's no cure, but treatment with medication and lifestyle changes such as diet modification and exercise can ease your symptoms. Sometimes symptoms may go away completely -- known as remission -- and these periods can last years at a time.

What are the first signs of psoriatic arthritis?

The first signs usually include joint pain and swelling, joint stiffness, fatigue, and changes to your fingernails. You may also notice patches of a psoriasis rash on your body if you weren’t already aware of having psoriasis.

Does psoriatic arthritis go away?

There is no cure for psoriatic arthritis, and it's a lifelong condition. However, it can go into remission, meaning that all your symptoms can go away for a period. This period can last days, weeks, months, or years.

What is the best cure for psoriatic arthritis?

There is no cure for psoriatic arthritis, but there are many different treatments that can help you manage the condition. You may have to try several different treatments before you find the best one for you. Some of the most effective treatments include disease-modifying antirheumatic drugs (DMARDs) and biologics.