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. Dr. Imundo says a common characteristic of PsA in children is a swelling of the fingers known as dactylitis, or sausage fingers.
Kids at Risk for Psoriatic Arthritis
“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 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.”
How Is PsA Diagnosed in Children?
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 that lab results and growth are normal in most kids diagnosed with psoriatic arthritis. 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.
Finding a Specialist Can Be Difficult
A board-certified pediatric rheumatologist is specifically trained to diagnose and treat arthritis in children. But there are fewer than 400 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.
Treating Psoriatic Arthritis in Children
Methotrexate is generally the first medication used to treat childhood psoriatic arthritis. If it does not work well to manage the disease, doctors often jump to a tumor necrosis factor (TNF) inhibitor, particularly if the pain is severe. “Children seem to tolerate the psoriatic arthritis medicines well,” says Imundo. “In a small percentage of patients, the TNF inhibitor may trigger psoriasis, so we constantly monitor our young patients.”
How Parents Can Help a Child With PsA
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.” She 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.” Because chronic pain adds to a child’s anxiety, parents should be sensitive to signs of depression and seek appropriate medical help as needed. 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.
