Psoriatic Arthritis vs. Osteoarthritis

You have psoriasis, and now you’re experiencing joint pain. Does this mean you have psoriatic arthritis? Or could it be unrelated?

“Osteoarthritis is the most common type of arthritis, and, sometimes, it can occur alongside psoriasis. Then again, psoriatic arthritis is also a possibility if you are experiencing skin symptoms,” says rheumatologist Rochelle Rosian, MD.

How can you make sense of it all? We talked to Dr. Rosian to find out what these types of arthritis have in common, how they differ and how to treat them.

Types of arthritis

“The word ‘arthritis’ is kind of a catch-all term,” Dr. Rosian explains. It’s used to describe more than 100 different conditions that cause pain, swelling and joint damage. Osteoarthritis and psoriatic arthritis are two of those many conditions.

What is osteoarthritis?

Osteoarthritis, or degenerative joint disease, is the most common type of arthritis. It occurs when the cartilage that cushions your bones wears down, leaving bone to rub against bone.

Since it’s caused by wear and tear on the joints over time, it usually develops in older adults. Unlike psoriatic arthritis, osteoarthritis doesn’t involve inflammation or an overactive immune system.

Osteoarthritis symptoms

Common features of osteoarthritis include:

• Symptoms that develop gradually over months or years.
• Pain and swelling in your joints.
• Pain that increases after stressing your joint (such as by walking or lifting heavy objects).
• A crunching sound or grinding sensation in affected joints.
• Changes in the shape of your joints, including bone spurs (bony growths near joints).

The location of the pain depends on the type of osteoarthritis:

• Primary osteoarthritis is most common in the fingers, thumbs, spine, hips, knees and big toes.
• Secondary osteoarthritis develops in joints that have been injured or damaged, such as from sports-related injuries or accidents. Secondary osteoarthritis can also develop in joints that have been damaged due to inflammatory diseases, including psoriatic arthritis. In other words, having psoriatic arthritis might increase your odds of developing osteoarthritis.

What is psoriatic arthritis?

Psoriatic arthritis is a type of inflammatory arthritis. It occurs when your body’s immune system works overtime, creating inflammation throughout your body. In psoriatic arthritis, that inflammation targets the joints and the places where tendons and ligaments attach to bones.

Most people with psoriatic arthritis also have psoriasis, a disease that causes red, scaly patches of skin. Psoriatic arthritis can strike at any age, though symptoms usually develop between ages 30 and 50.

Psoriatic arthritis symptoms

Psoriatic arthritis causes symptoms in your joints and beyond, including:

Joint symptoms:

• Symptoms that come and go suddenly in episodes known as flares.
• Pain and swelling in your joints (which may appear red and warm to the touch).
• Joint stiffness in the morning or after sitting for a long time.
• Tenderness or pain in your heel.

Skin symptoms:

• Swelling of an entire toe or finger, giving it a sausage-like appearance.
• Red or silver scaly spots on your skin (psoriasis).
• Pitting, ridges or detachment of fingernails and toenails.

Other symptoms:

• Fatigue.
• Inflammation of the eye.
• Anemia.

Do psoriatic arthritis and osteoarthritis look similar on X-rays?

In osteoarthritis, X-rays may show signs like worn cartilage. In psoriatic arthritis, X-rays can show joint damage in later stages of the disease.

But they aren’t especially helpful in making a diagnosis in the early stages. “X-rays can help make an arthritis diagnosis. But they aren’t always a slam dunk,” Dr. Rosian says.

X-rays can also reveal bone spurs, which can develop in people with osteoarthritis and psoriatic arthritis. Those images may reveal differences between the two diseases:

• Osteoarthritis bone spurs are more common in areas where cartilage and bone meet.
• Psoriatic arthritis bone spurs are more likely to form in the regions where tendons and ligaments attach to bone.

To diagnose joint disease, your healthcare provider will probably consider several factors in addition to X-rays, including:

• Blood tests.
• Physical exam.
• Medical and family history.

Arthritis treatment

Getting an accurate diagnosis is important since psoriatic arthritis and osteoarthritis require different treatments.

Medications are often an essential part of treating arthritis. But the medications can differ depending on the type.

Osteoarthritis treatments

Treatments for osteoarthritis include:

• Topical pain medicines.
• Intra-articular injection therapies (steroids and hyaluronic acid “gel” injections).
• Nonsteroidal anti-inflammatory medications (NSAIDs).

Psoriatic arthritis treatments

Treatments for psoriatic arthritis include:

• Nonsteroidal anti-inflammatory medications (NSAIDs).
• Disease-modifying antirheumatic drugs (DMARDs).
• Biologics.

Managing arthritis symptoms

In addition to medication, you can take other steps to manage arthritis symptoms. These approaches can help whether you have psoriatic arthritis or osteoarthritis:

• Low-impact exercise.
• Maintaining a healthy weight.
• Splints or braces to stabilize painful joints.
• Hot packs and cold packs to ease pain and swelling.

“By making certain lifestyle changes and working with your doctor to develop a treatment plan, you can keep arthritis symptoms in check,” says Dr. Rosian.