10 Psoriatic Arthritis Symptoms and Signs

Many people think of psoriasis as a skin condition marked by red, flaky, scaly patches of skin. Still, others don't know that there is often another side to psoriasis: arthritis.

Psoriasis and psoriatic arthritis are inflammatory autoimmune conditions. One affects your skin, while the other involves your joints, tendons, and ligaments.

Psoriasis vs. Psoriatic Arthritis

Nearly 20% of people with psoriasis in the United States develop psoriatic arthritis. And the fact that skin inflammation may trigger joint inflammation makes sense. With autoimmune diseases, your body mistakenly targets and attacks its healthy cells.

While both conditions can happen at any age, psoriasis tends to happen between ages 15–25. In contrast, the joint condition tends to happen later in life, between ages 30–50.

It's not entirely clear what causes either condition. But genetics seem to play a major role. Anywhere from 33% to 50% of people with psoriatic arthritis have a first-degree relative with the condition.

Psoriatic Arthritis Symptoms

Usually, people develop psoriasis before psoriatic arthritis symptoms appear. On average, psoriatic arthritis shows up seven to 10 years after seeing psoriasis symptoms. But some people have psoriatic arthritis without developing psoriasis symptoms.

"The underlying issue is psoriatic skin disease. And patients can have this for years before developing arthritis," Jonathan Greer, MD, a rheumatologist at Arthritis and Rheumatology Associates of Palm Beach, told Health. "Eight-five percent of patients will have skin disease before they develop joint disease."

If you're in the remaining 15%, you may wonder what some of the most common symptoms of psoriatic arthritis are. Here's what you need to know about the key signs of psoriatic arthritis to look out for.

Rashes and Redness

Because psoriatic arthritis starts as a chronic inflammatory skin disease, you may notice an onset of rashes. The traditional psoriatic skin rash is red, raised, and scaly, called plaques.

Plaque psoriasis may be painful or itchy and can appear on your elbows, knees, scalp, hands, feet, and lower back, among other places. 

Plaque psoriasis is one of the most common types of rash. But there are others, including smooth rashes that pop up in skin folds and rashes with blisters or pustules.

Swelling

With psoriatic arthritis, the tissues surrounding your joints commonly become inflamed, causing those joints to swell. Swelling frequently happens in the fingers and toes. Your joints may also appear red and feel warm to the touch.

Joint Pain

People with psoriatic arthritis are prone to joint pain because of increased swelling, John Gallucci, DPT, CEO of JAG-ONE Physical Therapy, told Health. 

"You'll notice it primarily in your fingers and toes or feel stiffness or tightness in your ankles, shoulders, and back," explained Dr. Gallucci.

Unlike other kinds of arthritis, psoriatic arthritis may or may not be symmetrical, meaning you experience "matching" joint pain on both sides of your body. Or joint pain may only occur in one joint of a traditional "pair," like your knees. Unfortunately, the pain can spread and worsen, especially if untreated.

Stiffness

People with psoriatic arthritis often experience joint stiffness, which affects their overall range of motion, noted Dr. Gallucci. Stiffness is common in the lower extremity joints, the hands, and the back.

However, the less you move because of that stiffness, the more limited your range of motion will become. So, it's important to maintain a basic exercise routine when you have arthritis.

Fatigue

Living with psoriatic arthritis can be exhausting, according to Dr. Gallucci.

"Patients are not only trying to move through their days with pain but are also not sleeping well at night because of that pain," said Dr. Gallucci. Serious fatigue goes hand-in-hand with psoriatic arthritis and can become debilitating.

Joint Disability

To understand what's happening to your joints, you need to know about cytokines. Cytokines are proteins that play a role in the regulation of your immune response.

But for people with autoimmune conditions like arthritis, cytokines can flood otherwise healthy tissue, causing inflammation and pain. Additionally, serious bone damage may occur.

"Cytokines attack the joints, which can make the joints feel spongy, can erode the bones, and even cause joint fusion," said Dr. Greer.

The bone may also deviate to a point where it causes mechanical issues and incongruity between joints, also known as bone erosion. Bone erosion can affect your ability to bear weight on your joints without an assistive device, added Dr. Gallucci.

Fingernail Defects

Don't overlook that fingernails and toenails are commonly affected by systemic skin conditions, and psoriatic arthritis is no exception. 

Nails might become thickened, crumbly, or more prone to fungal infections, said Dr. Greer. Also, nails may show signs of pitting and even separate from the nailbed.

If a healthcare provider isn't sure if your nail problems are related to psoriatic arthritis, a nail biopsy could be performed, said Dr. Greer.

Eye Inflammation

There's also a chance of uveitis, an inflammation of the middle layer of eye tissue. Your eyes may become red and irritated, and you may have pain or notice changes in your vision, like blurriness.

That eye inflammation is common with all spondyloarthritis diseases, including psoriatic arthritis, noted Dr. Greer. Cytokines can affect the healthy tissues of your eyes.

You may also have other inflammatory conditions, such as inflammatory bowel disease (IBD) or Crohn's disease.

Inflammatory Back Pain

Everyone over the age of 30 has some back pain, right? So, how can you tell if yours is a warning sign of psoriatic arthritis?

"Back pain from psoriatic arthritis gets worse with rest and better with activity, which is the opposite of 95% of [the other causes of] back pain," explained Dr. Greer. With psoriatic arthritis, you're dealing with more than a pulled muscle or overuse injury, also known as mechanical back pain.

Instead, inflammatory back pain develops when abnormalities are on and around your vertebrae. Those abnormalities can cause the joints of your spine to fuse, which is painful and can limit your range of motion.

Enthesitis

Psoriatic arthritis is known for causing joint pain and inflammation. But it can also affect the enthesis, where a tendon connects to a bone. When an enthesis becomes inflamed, it's known as enthesitis. About one in three people with psoriatic arthritis experience enthesitis.

"People may have tendonitis for a long time without realizing it's psoriatic arthritis," explained Dr. Greer. "And in some cases, it may even be the first symptom." 

Common spots for enthesitis are the ankles, heels, and bottoms of the feet. However, enthesitis can also happen in your knees, elbows, shoulders, hips, and joints typically affected by arthritis.

A Quick Review

Psoriatic arthritis is often seen alongside psoriasis. But symptoms can appear without a psoriasis diagnosis. Some of the most common symptoms of psoriatic arthritis are joint pain, disability, stiffness, fatigue, and enthesitis. 

Other symptoms like psoriasis include rashes, redness, swelling, and fingernail defects. Be sure to see a healthcare provider who can diagnose your condition.