The 6 Main Ways Psoriatic Arthritis Affects Your Body

Psoriatic arthritis, or PsA, is an inflammatory type of arthritis, which sets it apart from the more traditional and well-known osteoarthritis. PsA is a chronic and autoimmune disease, meaning it’s caused by an overactive immune system that attacks healthy, normal cells in the body.

With PsA, “your joints get enlarged and restricted and stiff, and there’s inflammation in the joint space, as opposed to a bone-on-bone arthritis, or osteoarthritis, where you lose the joint space,” says Nicola Kim Berman, MD, a rheumatologist based in New York.

PsA can be categorized by symptoms in different areas of the body, based on which joints are affected, but they aren’t necessarily distinct. “At different points in time, you could have swelling of your knee, and then you could have back pain, and then, later on, you could develop some pain in your hands — or it could present similarly at the same time," says Dr. Berman.

There are 6 ways psoriatic arthritis affects the body:

1. Arthritis causes joint pain and swelling.PsA primarily affects the distal interphalangeal joints, which are the last joints at the ends of fingers and toes. But it can affect other joints. PsA can be symmetric, which means it affects joints on both sides of the body. But it can also be asymmetric and affect only a few joints, which is called oligoarticular PsA, which accounts for about 35 percent of PsA diagnoses. 

2. Nail changes, skin rashes, and fatigue that are common in psoriasis and are also common in PsA. Most people with PsA are likely to experience nail changes in their fingernails and toenails. 

3. Dactylitis is the swelling of small joints and tendons that affect individual fingers or toes.

4. Enthesitis causes inflammation in where tendons attach to bone, most commonly the Achilles tendon at the heel.

5. Spondylitis causes pain and stiffness in the spinal column: the spine, neck, lower back, and sacroiliac joints (which connect the spine to the hips). Spondylitis affects 20 percent of people with PsA. 

6. Arthritis mutilans is the most severe form of PsA, but it’s also less common: It accounts for just 5 percent of PsA diagnoses. It causes damage and deformities to the joints, especially the fingers and toes. “That’s a rapidly destructive form of arthritis that leads to deformities quite quickly,” says Dr. Berman.

Treating PsA takes several factors into account. For example, in more severe cases — such as arthritis mutilans — they may require more aggressive treatment options.

“There’s been a lot of advances in psoriatic arthritis, and our ability to treat these conditions has very much so changed for the better in the last couple of years,” says Dr. Berman. “There’s a very promising trajectory for our treatments for psoriatic arthritis.”

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Written by:

Lauren Smith, MA

Lauren Smith, MA, has worked in health journalism since 2017. Before joining GoodRx, she was the senior health editor and writer for HealthiNation.

Reviewed by:

Sarah Gupta, MD

Sarah Gupta, MD, is a licensed physician with a special interest in mental health, sex and gender, eating disorders, and the human microbiome. She is currently board certified by the American Board of Psychiatry and Neurology.

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