When Psoriatic Arthritis Strikes at a Young Age

Psoriatic arthritis is most common in adults between ages 30 and 50, but it can strike the very young. Early diagnosis and proper treatment are key to managing the disease’s symptoms and preventing joint damage.

The Arthritis Foundation estimates that nearly 300,000 U.S. children under age 18 have some kind of pediatric arthritis, such as psoriatic arthritis (PsA).

“I’ve seen psoriatic arthritis in infants at one year of age. While it’s not the most common age, the incidence increases as children approach the teenage years,” says Lisa Imundo, MD, a board-certified pediatric rheumatologist at the Columbia University Irving Medical Center in New York City. There is a peak at ages 2 to 5 and a second peak during teenage years, she notes.

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“While anyone can get psoriatic arthritis, kids have a higher risk of being diagnosed if they have a first-degree relative, meaning a sibling or parent, with psoriasis or psoriatic arthritis,” says Dr. Imundo.

But genes are not predictive with psoriatic arthritis, and there is no clinical standard for a genetic test. “No test will tell if PsA will or won’t happen,” she adds. “It appears that it’s a series of genes and environmental triggers, whether an illness, immune system problem, or a cascade of triggers.”

Other risk factors include having nail psoriasis and obesity in addition to having a first-degree relative with psoriasis.

Imundo also notes that many children do not have the rash of psoriasis when they first develop the arthritis.

Unlike some types of arthritis, there is no specific blood test to diagnose psoriatic arthritis in children. “Children may present with some inflammation signs in the blood,” says Imundo. “Their growth may be lagging, or they could have some anemia.”

But on the whole, she says, lab results and growth are normal in most kids diagnosed with psoriatic arthritis.

Imundo says a common characteristic of PsA in children is a swelling of the fingers known as dactylitis, or sausage fingers.

Doctors make a diagnosis on the basis of a child’s symptoms, whether that's stiffness or pain, tenderness in certain places, swelling of joints, or contracture. Psoriatic arthritis can also involve tendons, inflammation at the sites where tendons attach to bone (enthesitis), and inflammation of the tendon joints in the low back (sacroiliitis).

In adults, the majority of psoriatic arthritis cases occur in patients with preexisting psoriasis, while for children, it’s the opposite situation: Skin disease typically happens up to 10 years after the development of arthritis, according to research. This adds to the difficulty of diagnosing juvenile PsA.

A board-certified pediatric rheumatologist is specifically trained to diagnose and treat arthritis in children. But there are only around 420 U.S. doctors who specialize in the area, according to the Arthritis Foundation. So parents may have to travel a distance with their child for an appointment with a specialist.

Additionally, if the child has skin and nail involvement with psoriasis, their treatment team will likely include a dermatologist.

Nonsteroidal anti-inflammatory drugs (NSAIDs) may be used first to treat joint inflammation symptoms. Methotrexate (Trexall) — a disease-modifying anti-rheumatic drug (DMARD) — might be used in younger children with childhood arthritis, but Imundo notes that there are new treatments now approved for children. And certain manifestations, such as sacroiliitis or enthesitis, would be treated with biologic medications.

Biologic drugs include tumor necrosis factor (TNF) inhibitors. TNF inhibitors used for pediatric PsA include infliximab (Remicade), adalimumab (Humira), etanercept (Enbrel), and golimumab (Simponi). Other approved agents now being used — especially if the psoriasis is severe — include secukinumab (Cosentyx) and ustekinumab (Stelara).

In 2023, the U.S. Food and Drug Administration (FDA) expanded the approval of abatacept (Orencia), a DMARD, to treat psoriatic arthritis in children over 2 years old.

“Children seem to tolerate the psoriatic arthritis medicines well,” says Imundo. “In a small percentage of patients, the TNF inhibitor adalimumab may trigger psoriasis, so we constantly monitor our young patients.”

In addition to medication, Imundo also recommends physical therapy, which is vital for range of motion. “Equally important are low-impact activities, such as swimming, biking, and low-impact aerobics,” she adds. “I urge teens to spend more time doing yoga and less time weight lifting.” Generally, however, she doesn’t restrict her patients and encourages them to choose activities they enjoy.

Imundo points to evidence that omega-3 fatty acids in fish oil supplements can help reduce inflammation. She also monitors patients’ levels of vitamin D. “Lack of vitamin D can predispose the child to an autoimmune type of reaction,” she says. Although omega-3s and vitamin D can be helpful as part of a treatment plan, she adds, they’re not effective alone for severe arthritis.

There’s a definite mind-body connection with psoriatic arthritis, explains Imundo. “Because pain is a stressor, parents can help children by ensuring they get plenty of sleep each night.”

Since chronic pain adds to a child’s anxiety, parents should be sensitive to signs of depression and seek appropriate medical help as needed.

Kids may often miss school and interactions with their peers, so a good support system is important.

And because there’s a link between psoriatic arthritis and eye diseases, such as uveitis (inflammation of the uvea, the middle layer of the eye), regular exams by an ophthalmologist are recommended, notes the Children’s Hospital of Philadelphia.

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With proper treatment, Imundo says, patients can expect to have this chronic condition fully under control, with no skin lesions and no pain or swelling over time.

As children with psoriatic arthritis get older, they can often go off of some medications once they achieve a full response and have no active disease.

Additional reporting by Deborah Shapiro.