What Everyone with Psoriasis Should Know About Psoriatic Arthritis

What Exactly Is the Connection Between Psoriasis and Psoriatic Arthritis?

Psoriasis and psoriatic arthritis are both psoriatic diseases. But they’re two distinct conditions: Psoriasis affects the skin, while psoriatic arthritis is a joint disease.

While the precise cause of these two chronic, incurable conditions is unknown, they’re both the result of an immune system gone awry.

With psoriasis, this leads to “skin cells turning over very, very rapidly,” explains Suzanne Friedler, M.D., a dermatologist at Advanced Dermatology P.C. in New York City. This makes skin get red, flaky, itchy, and uncomfortable, she says. With psoriatic arthritis, the immune system attacks healthy cells, causing joint inflammation, which results in swelling, pain, and stiffness.

One of several common threads between the two conditions is inflammation: Inflammation causes skin-related issues in people with psoriasis and also causes symptoms in the joints for people with psoriatic arthritis, says Magdalena Cadet, M.D., a New York City-based rheumatologist.

“There is a suggestion that there may be a link to inflammatory proteins called cytokines that have been found overlapping in both conditions,” Cadet adds.

The biggest risk factor for developing psoriatic arthritis is having psoriasis, according to the Mayo Clinic, but a family history also increases your risk. So too do environmental factors such as stress, infections, and obesity, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

These Conditions Can Occur Anytime

Both psoriasis and psoriatic arthritis can strike at any age. But psoriasis commonly appears when people are in either their 20s or 50s, according to the National Psoriasis Foundation. Psoriatic arthritis tends to first occur in middle-aged people, anywhere from their mid-30s to their 40s, Cadet says.

“Psoriatic arthritis can present years after the onset of psoriasis,” Friedler says. It’s typical for psoriatic arthritis to occur seven to 10 years after a person first develops psoriasis, according to the National Institutes of Health.

More rarely, the reverse can occur, with people with psoriatic arthritis going on to develop psoriasis, Cadet notes.

Early Signs of Psoriatic Arthritis

Recognizing the early signs of psoriatic arthritis is essential. Without treatment, the condition can cause permanent, irreversible joint damage.

But some symptoms can easily be missed, particularly the ones that mirror psoriasis.

Diagnosing psoriatic arthritis is challenging. “There's not a single test that actually diagnoses psoriatic arthritis,” says Cadet, adding that symptoms can mirror other forms of arthritis. Rheumatologists use a combination of blood tests, X-rays, MRIs, and patient history to make the diagnosis.

Keep an eye out for these common psoriatic arthritis symptoms—and tell your doctor right away if you experience any of them:

• Joint swelling, tenderness, and stiffness: This can occur in the peripheral joints (think: arms, legs, hands, and feet) but can also occur in the spine. “A lot of times people complain of back stiffness,” Cadet says. For many, joint stiffness tends to be worse in the morning and improve throughout the day.
• Sausage digits: Puffy swelling of your fingers or toes, more formally known as dactylitis, is a symptom of psoriatic arthritis. The exact location of the pain and swelling in the fingers can help doctors tell the difference between psoriatic arthritis and rheumatoid arthritis, Cadet says.
• Nail changes: Yellowed nails or changes to your nail beds can also occur in people with psoriatic arthritis.
• Foot pain: Psoriatic arthritis can lead to inflammation where tendons and ligaments attach to bone, which is known as enthesitis, which can cause pain and stiffness and lead to overuse injuries.

“Most people have joint complaints as they age,” Cadet notes. When the stiffness lasts longer or joint swelling occurs, it’s wise to see a rheumatologist, she says.

Treatment Options for Psoriatic Disease

There are an array of treatments available for psoriasis, Friedler says, including topicals and phototherapy, which can be beneficial for clearing up the skin for people with psoriasis. For psoriatic arthritis, there are several other treatment options available, including nonsteroidal anti-inflammatory medications.

If you have both psoriasis and psoriatic arthritis, you and your doctor may opt for systemic treatments, which reduce inflammation throughout the body and can tackle both skin and joint symptoms. These include oral medications and biologics, which are given as either an infusion or an injection.

“Some of the newer medications that treat psoriasis, specifically, the biologic treatments, often are anti-inflammatory and they have joint protection properties, as well,” Friedler notes.

If you have both psoriasis and psoriatic arthritis, you’ll likely consult with a dermatologist as well as a rheumatologist to determine the best treatment approach.

The severity of your symptoms and how much they’re impacting your life will be major factors in your treatment.

Stay on the Lookout

Since you’re at higher risk of developing psoriatic arthritis, it’s crucial to keep a close eye on what’s happening with your body. In fact, psoriatic arthritis is seen as both underdiagnosed and undertreated, according to an article in the American Journal of Managed Care. One systematic review of studies found that around 15 percent of cases of psoriatic arthritis go undiagnosed.

If you have psoriasis, it’s important to be screened every six months for psoriatic arthritis, as recommended by the National Psoriasis Foundation.

“As a dermatologist, I ask patients about joint symptoms, as well,” Friedler says. Your dermatologist should be able to refer you to a rheumatologist who can more closely examine any joint-related issues.

If you’re feeling concerned, and wondering if you might be showing signs of psoriatic arthritis, you should make an appointment with a doctor as soon as possible. Use this psoriatic arthritis assessment tool to help you pinpoint potential symptoms to discuss with your provider—just one “yes” answer is worth a visit to a rheumatologist.

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