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Psoriatic arthritis (PsA), a form of chronic inflammatory arthritis, is characterized by symptoms of joint pain, swelling, and stiffness. These symptoms occur when the body’s immune system mistakenly attacks healthy tissue, causing inflammation and damage that limits range of motion and mobility. About 30 percent of people who have psoriasis, or a family history of the skin disorder, eventually develop PsA, according to the National Psoriasis Foundation.
Psoriatic arthritis affects everyone differently. Some people have only one joint involved; others may have three or more impacted joints. Symptoms can be mild and develop slowly or arise suddenly and severely. They can include swelling in fingers and toes, heel pain, an achy lower back, or pitted nails.
Because psoriatic arthritis shares many symptoms with rheumatoid arthritis (RA), it’s often misdiagnosed, particularly in the absence of psoriatic skin lesions. In a 2018 study, 96 percent of people with psoriatic arthritis received at least one previous misdiagnosis, and 30 percent were only diagnosed after five years or more.
Recognizing the signs and symptoms of psoriatic arthritis is critical for early diagnosis. Studies have shown that even a six-month delay in getting a diagnosis, or starting medication after first noticing psoriatic arthritis symptoms, can impact treatment effectiveness and lead to a worse outcome.
A rheumatologist can identify PsA symptoms and evaluate treatment options to manage them. The National Psoriasis Foundation also offers a five-question quiz to assess if you have the symptoms of psoriatic arthritis.
There are five types of psoriatic arthritis, each defined by the impacted joints. Large and small joints can be involved. It’s also possible to have more than one PsA type.
One of the most common types of psoriatic arthritis, asymmetric oligoarthritis occurs in 70 percent to 80 percent of people with PsA. The mildest form of PsA, it typically involves one to four joints on just one side of the body.
Symmetric polyarthritis affects 5 percent to 20 percent of people with psoriatic arthritis. It generally progresses from minimal joint involvement on one side of the body to five or more joints on both sides of the body. Polyarthritis is a hallmark symptom of rheumatoid arthritis and PsA symptoms can be confused with that disorder.
Spondylitis, or psoriatic arthritis of the lower back and spine, affects 5 percent to 20 percent of people with PsA. Inflammation between vertebrae causes pain, swelling, morning stiffness, and limited mobility in joints of the neck, lower back, and sacroiliac region near the pelvis. In some people, spondylitis also affects the skin, intestines, and eyes, according to the American College of Rheumatology. Unchecked, it can lead to bone damage, deformities, and fusion in the spine. You can learn more about spondylitis at MySpondylitisTeam.
Distal arthritis refers to inflammation and stiffness in the distal interphalangeal joints, those closest to the tips of fingers and toes. Nail changes — another psoriatic arthritis differentiator — are common with distal arthritis, which is experienced by 10 percent of people with PsA.
The rarest and most severe type of psoriatic arthritis, arthritis mutilans attacks joints in the hands and feet, causing deformations and impaired movement. Bone loss in the joints can cause shortening of fingers and toes. Neck and back pain may also occur.
Psoriatic arthritis not only affects the body’s joints. It can also create symptoms in the skin, eyes, and other organs. The following symptoms include early warning signs, as well as common indicators of advanced disease.
A painful, sausage-like swelling of an entire finger or toe, dactylitis is the first symptom someone with psoriatic arthritis might experience, and a hallmark of the disease. It can affect multiple digits on either side of the body and lead to permanent joint damage if untreated. Sausage digits may also be a sign of disease progression.
Pitting, ridging, and flaking under the nail, or separation from the nail bed (known as onycholysis), are early PsA symptoms. They are unique to this arthritic disease. Up to 90 percent of people with PsA experience nail changes. Nail changes may appear on one finger or toenail or on all 20 nails.
Swollen, tender joints — a common psoriatic arthritis symptom — are caused by inflammation of the entheses, the place where ligaments attach to the bone. Nearly 50 percent of people with PsA experience this symptom, most frequently in the plantar fascia (bottom of the feet) and Achilles tendon (heel), making it painful to walk. Enthesitis can also affect the spine, elbows, ribs, and neck, making tissues in these areas tight and ropey.
Psoriatic arthritis also attacks the large joints of the arms and legs, causing swelling and pain. Fingers and toes, as well as elbows, wrists, knees, and ankles may also be affected.
Itchy, red or silvery lesions appear prior to the onset of psoriatic arthritis in approximately 75 percent of people with PsA. Skin disease can appear an average of seven to 12 years before developing PsA. Some studies found that psoriasis can be more severe in people with PsA.
Uveitis, an inflammatory eye condition, is common in people with PsA (as well as for people with rheumatoid arthritis). Swelling of the uvea, the middle layer of the eye, causes pain, redness, sensitivity to light, and decreased or blurry vision. Left untreated, uveitis can damage eye tissue and lead to vision loss.
High levels of inflammation have been linked to fatigue in PsA. The physical and emotional challenges of living with a debilitating chronic illness are also contributors. A Danish survey of 1,062 people with PsA found that 50 percent had moderate-to-severe fatigue. An earlier study observed that 1 in 5 people with PsA also have fibromyalgia, which causes fatigue.
People with PsA often experience mood disorders. A 2014 study found that more than 36 percent of individuals with the disease reported some degree of depression or anxiety. Those studied also had high levels of joint disease, disability, and fatigue.
Psoriatic arthritis also increases the risk of other health conditions, or comorbidities, including:
Symptoms of psoriatic arthritis typically appear between the ages of 30 and 50. They may arise gradually or suddenly, or flare up periodically. PsA may also affect one or more joints — most commonly in the hand, foot, or knee — and worsen over time, according to the American Academy of Dermatology.
PsA typically develops about 10 to 20 years after the onset of psoriasis, but PsA can present even before skin symptoms appear. Most people are first examined by a dermatologist or internist to identify PsA symptoms, before being referred to a rheumatologist, who specializes in arthritis.
Psoriatic arthritis and rheumatoid arthritis are both autoimmune diseases involving inflammation that causes pain, swelling, and stiffness in joints. The disease can flare up or go into remission. A PsA diagnosis, however, requires an individual to have at least three of the following:
There’s no cure for PsA, and symptoms may increase during disease flares. With some types of PsA, joint symptoms are progressive and can lead to disability. Remission occurs in less than 20 percent of people with psoriatic arthritis.
Fortunately, there are treatments that can help manage symptoms of PsA and slow disease progression. Early diagnosis is important. Left unchecked, inflammatory symptoms can worsen and cause permanent damage that leads to disability.