Psoriatic Arthritis in Children
What is psoriatic arthritis?
Psoriatic arthritis is a form of arthritis associated with psoriasis. Psoriasis is a chronic skin and nail disease. It causes red, scaly rashes and thick, pitted fingernails. Psoriatic arthritis is similar to rheumatoid arthritis (RA) in symptoms and joint inflammation. But it tends to affect fewer joints than RA. And it does not produce the typical RA antibodies. The arthritis of psoriatic arthritis comes in 5 forms:
- Arthritis that affects the small joints in the fingers and/or toes
- Asymmetrical arthritis of the joints in the hands and feet
- Symmetrical polyarthritis, a type of arthritis similar to rheumatoid arthritis
- Arthritis mutilans, a rare type of arthritis that destroys and deforms joints
- Psoriatic spondylitis, arthritis of the lower back (sacroiliac sac) and the spine
Psoriatic arthritis is one of 4 disorders which are classified as spondyloarthropathies. The other disorders are:
- Juvenile ankylosing spondylitis
- Inflammatory bowel disease
- Reiter's syndrome
These disorders have similar features such as:
- Inflammation of the spine and sacroiliac joints
- Family history of the disease
- Similar nonarthritis symptoms
- No rheumatoid factor in the blood (an antibody found in the blood of most people who have rheumatoid arthritis (RA) and other rheumatic diseases)
What causes psoriatic arthritis?
The cause of psoriatic arthritis is unknown. But factors such as immunity, genes, and the environment may play a role.
What are the symptoms of psoriatic arthritis?
Symptoms can occur a bit differently in each child. The skin condition psoriasis may start before or after the arthritis. Psoriasis causes scaly, pinkish-red, itchy rash on the knees, elbows, scalp, face, and folds of the buttocks. It can also cause pitting of fingernails or toenails. Symptoms of psoriatic arthritis may include:
- Inflamed, swollen, and painful joints, usually in the fingers and toes
- Morning stiffness in the joints
- Reddened skin over the affected joints
- Sausage-like swelling of fingers and toes, plus swollen wrists (more common in girls age 1 to 6)
- Deformed joints from chronic inflammation
- Symptoms in the spine or sacroiliac joint (more common in older children)
- Eye pain
The symptoms of psoriatic arthritis can be like other health conditions. Make sure to see your healthcare provider for a diagnosis.
How is psoriatic arthritis diagnosed?
Psoriatic arthritis is easier to confirm if your child already has psoriasis. If the skin symptoms have not yet occurred, diagnosis is more difficult. The process starts with a medical history and a physical exam. Your healthcare provider will ask about your child's symptoms. Your child may have blood tests to check:
Erythrocyte sedimentation rate (ESR or sed rate). This test looks at how quickly red blood cells fall to the bottom of a test tube. When swelling and inflammation are present, the blood's proteins clump together and become heavier than normal. They fall and settle faster at the bottom of the test tube. The faster the blood cells fall, the more severe the inflammation.
Uric acid. High blood uric acid levels are linked with psoriatic arthritis.
Complete blood count (CBC). This test checks for low counts of red blood cells (anemia), white blood cells, and platelets.
Antibody blood tests. These tests are done to look for certain kinds of antibodies in your blood. The main test for lupus is the antinuclear antibodies (ANA) test. Most people with lupus will have a positive ANA test result. Other tests check for other kinds of antibodies.
These tests can be positive for many kinds of rheumatic diseases. But younger children are more likely to have a positive ANA test.
Other tests may include:
X-rays. This test that uses a small amount of radiation to create images of organs, bones, and other tissues.
Eye exam. This is done by a pediatric ophthalmologist. The exam looks for uveitis, a swelling of the middle layer of the eye.
How is psoriatic arthritis treated?
Treatment will depend on your child's symptoms, age, and general health. It will also depend on how severe the condition is. The treatment team will include your child's primary healthcare provider. It will also include a pediatric rheumatologist, and an ophthalmologist.
Treatment is done for both the skin condition and the joint inflammation. Some medications used to treat psoriatic arthritis include:
- Nonsteroidal anti-inflammatory medications to relieve symptoms
- Vitamins and minerals, such as calcium and vitamin D, to slow bone deformation
- Immunosuppressive medications, such as methotrexate, to suppress inflammation if NSAIDs are not effective
- Biologic medications, such as infliximab
- Corticosteroids for inflammation
Other treatment may include:
- Ultraviolet light treatment (UVB or PUVA)
- Heat and cold
- Physical therapy to improve and maintain muscle and joint function
- Occupational therapy to improve ability to perform activities of daily living
- Management of psoriasis skin rash
- Surgery to repair or replace a damaged joint (usually not needed until years after diagnosis)
What are the complications of psoriatic arthritis?
Children with psoriatic arthritis may go into remission. This means that their symptoms may go away fully. This is more likely with early diagnosis and treatment. When treatment is delayed, remission is less likely. In these cases, the condition may lead to long-term disability.
Helping your child live with psoriatic arthritis
Help your child manage his or her symptoms by sticking to the treatment plan. This includes getting enough sleep. Encourage exercise and physical therapy and find ways to make it fun. Work with your child's school to make sure your child has help as needed. Work with other caregivers to help your child take part as much possible in school, social, and physical activities. Your child may also qualify for special help under Section 504 of the Rehabilitation Act of 1973. You can also help your child find a support group to be around with other children with pediatric arthritis.
Key points about psoriatic arthritis
- Psoriatic arthritis is a form of arthritis with a skin rash.
- Psoriasis is a chronic skin and nail disease. It causes red, scaly rashes and thick, pitted fingernails. The rash may come before or after the arthritis symptoms.
- Psoriatic arthritis causes inflamed, swollen, and painful joints. It also causes eye pain and fatigue.
- Treatment may include medicines, heat and cold, splints, exercise, physical therapy, and surgery.
- Early treatment can help your child achieve remission. Delayed treatment may lead to long-term disability.
Tips to help you get the most from a visit to your child’s healthcare provider:
- Before your visit, write down questions you want answered.
- At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you for your child.
- If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.
- Fetterman, Anne, RN, BSN
- Freeborn, Donna, PhD, CNM, FNP