Psoriatic arthritis (PsA) and psoriasis are two chronic diseases. Their names may sound similar, but they are different health conditions.

PsA is an inflammatory form of arthritis. It can affect joints on one or both sides of your body. Psoriasis is an immune system disorder that affects your skin.

The two conditions share some genetic similarities. However, the link between them isn’t fully understood.

And while PsA usually occurs along with psoriasis, you can have either condition without the other.

You can have PsA if you don’t have psoriasis, though it’s uncommon. Usually, psoriasis will develop before or at the same time as PsA.

A study from 2017 found that only 14.8 percent of participants received a diagnosis of PsA before psoriasis.

You can also have psoriasis without having PsA. About 30 percent of people with psoriasis also have PsA, according to the National Psoriasis Foundation.

If you have psoriasis and develop PsA, you’ll usually receive the PsA diagnosis within approximately 15 years.

It’s still unclear why only some people with psoriasis also develop PsA.

PsA causes stiffness, pain, and swelling around the joints. Symptoms of PsA are often different in each person but can include:

  • swelling in fingers or toes
  • throbbing, stiffness, swelling, and soreness in joints
  • pain
  • inflamed areas of skin
  • fatigue
  • changes to the nails, including pitted nails or separation from the nail bed
  • inflammation of the eyes

Psoriasis mainly affects the skin. It can also affect your nails. Some of the main symptoms of psoriasis include:

  • raised, dry, red patches on the torso, elbows, and knees
  • silvery, scaly plaques on the skin
  • small, red, individual spots on the skin
  • dry skin that can crack and bleed
  • itchy, burning, or sore skin
  • nail pitting and separation from the nail bed

You’re at an increased risk for PsA if you have psoriasis. Up to 30 percent of people with psoriasis may develop PsA.

Severe psoriasis and obesity may also be linked to a higher chance of PsA.

Family history of the condition also increases your risk. Around 40 percent of people with PsA have a family member with psoriasis or arthritis.

Age is another factor. PsA is most likely to develop in people between the ages of 30 and 50.

Currently, no single test can confirm PsA. Your doctor will likely ask about your family medical history and conduct a physical exam.

They may examine your joints and fingernails and look for skin changes associated with psoriasis. They may request X-rays and MRI scans to check for changes in the joints and to rule out other causes of joint pain.

A healthcare professional may also order laboratory tests, such as the rheumatoid factor test or the cyclic citrullinated peptide test, to help rule out the possibility of rheumatoid arthritis.

Your doctor may also take fluid from a joint, such as the knee, to rule out gout.

There’s no cure for PsA at this time. Your doctor will instead focus on keeping the disease from progressing while helping you manage your symptoms.

They will base your treatment on the severity of your condition and may prescribe several different medications to identify the ones that are most effective for you.

Common medications used to treat PsA include the following:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs). You’ll likely try ibuprofen (Advil, Motrin) or naproxen sodium (Aleve) first if your disease is mild.
  • Disease-modifying antirheumatic drugs (DMARDs). Methotrexate (Trexall), sulfasalazine (Azulfidine), cyclosporine (Gengraf), and leflunomide (Arava) can reduce inflammation by suppressing your immune system.
  • Tumor necrosis factor (TNF)-alpha inhibitors. Etanercept (Enbrel), golimumab (Simponi), adalimumab (Humira), and infliximab (Inflectra, Remicade) block a substance called TNF that causes inflammation.
  • IL-17 inhibitors. Secukinumab (Cosentyx) and ixekizumab (Taltz) may be used for severe psoriasis or if you’re unable to take, or don’t respond to, a TNF inhibitor.
  • Janus kinase (JAK) inhibitors. Tofacitinib (Xeljanz) may help if other medications are ineffective.

Why is early treatment important?

PsA can cause permanent joint damage when left untreated. In severe cases, the joints may become so damaged that they no longer function. This is why recognizing it early is important for overall health.

Having PsA also increases your risks for other conditions, including:

If you have PsA, it’s important to see your doctor for regular checkups. They can help monitor your weight and test you for conditions like high blood pressure or diabetes. Screenings can help you start treatment early if you develop any other conditions.

You can have PsA even if you don’t have psoriasis. People with psoriasis are at an increased risk for this condition, however.

There’s currently no cure for PsA. With early diagnosis, your doctor can treat your symptoms and slow the progression of the condition.