Inflammatory Arthritis in Children: More than Growing Pains

Growing pains are a fact of life for many children, and are harmless and transient. But when the pain doesn't go away, is worse in the morning, or is associated with other symptoms, it's time to take a closer look.

When should I call the pediatrician if I think my child has arthritis?

Kids report various degrees of musculoskeletal pain frequently, and this is often not a cause of concern. Growing pains may manifest as discomfort in the legs, typically at night, which subsides in minutes or hours and is usually gone by the morning. Sports injuries, such as sprains or strains, often have a clear inciting event, are worse with activity, and improve over time.

If your child has pain which does not fit either of those patterns or is experiencing any of the following symptoms, it is time to call your pediatrician for a visit to learn if your child should see a pediatric rheumatologist (medical doctor specializing in joint and autoimmune diseases in children):

• Pain in a joint accompanied by swelling, warmth, and decreased range of motion.
• Joint pain when your child wakes up that improves during the day. Your child may walk stiffly in the morning, almost like an elderly person.
• Pain that stops your child from enjoying their favorite activities.
• Joint pain accompanied by fever and/or a rash.

What causes juvenile inflammatory arthritis?

We don't completely know the answer, although a complex interplay between genetics, the immune system, and the environment is at the root. Juvenile idiopathic arthritis is considered an autoimmune disease, where the immune system attacks the body’s own tissues. JIA is a diagnosis of exclusion, meaning that other diseases and causes of your child's symptoms are ruled out before making a diagnosis of JIA. The pediatric rheumatologist will order tests such as blood tests, imaging exams (X-ray, ultrasound, MRI), and sometimes analysis of fluid removed from a swollen joint to diagnose juvenile arthritis.

Types of juvenile idiopathic arthritis

There are several types of JIA, classified according to the number of joints they affect, their symptoms, and the results of blood tests used to diagnose them. While all types can affect children of any age, some are more likely in certain age groups and sexes. Types of JIA include oligoarticular, polyarticular, psoriatic, enthesitis-related, and systemic-onset JIA (formerly known as “Still’s disease).

Oligoarticular JIA

This is arthritis that affects four or fewer joints in the first six months of the disease – usually joints of the lower extremities, such as the knee.

• Who's affected: Young children, usually girls.
• Symptoms: Children typically have one large swollen joint, often a knee. They may or may not complain of pain. The joint is stiff and may cause problems with walking, particularly in the morning. Toddlers may have delayed milestones, or regress. There are rarely any other problems, such as a general feeling of being sick.
• Diagnosis: The child may test positive on a blood test for antinuclear antibodies (ANA), a marker that the immune system is attacking one's own tissues. But positive ANA tests are also seen with other autoimmune diseases, as well as in healthy people with no underlying disease.
• Treatments: First, nonsteroidal anti-inflammatory drugs (NSAIDs) are given, such as ibuprofen. Some children benefit from a steroid injection into an affected joint to relieve inflammation. If these treatments are not sufficient, the child may need to take a disease- modifying antirheumatic drug, or DMARD (such as methotrexate, sulfasalazine, leflunomide, or hydroxychloroquine), or a targeted "biologic" drug (such as adalimumab, etanercept, tocilizumab, or abatacept) that zeroes in on the proteins driving inflammation. Physical therapy is important to maintain or improve range of motion in the affected joint.
• Possible complications: Inflammation of the eye, called uveitis, is a common complication, especially in young girls who test positive for ANA. It may be silent, chronic, and progressive, and if untreated, may lead to permanent vision loss. Uveitis may require treatment with steroid eyedrops and/or DMARDs and biologic drugs. Regular monitoring of eye health by a pediatric ophthalmologist is vitally important for children with JIA to detect and treat uveitis before it causes blindness. Children with this type of JIA are also at risk of having a limb length discrepancy, with the affected leg growing longer than the other due to the increased blood flow caused by inflammation. Doctors may order periodic screening with X-rays to check for this issue and escalate the intensity of treatment to slow or prevent this problem. Inflamed joints may also form contractures (stiffened tissue in an affected joint), leading to decreased range of motion.

Polyarticular JIA

This type affects five or more joints in the first six months of the disease, including smaller joints such as those in the hands and fingers.

• Who's affected: Young children through adolescents, mostly girls
• Symptoms: Of all the types of JIA, polyarticular JIA most closely resembles rheumatoid arthritis in adults. Children may have swelling, pain, and stiffness in multiple joints, as well as fatigue and a general sense of feeling unwell. Diagnosis: The child may test positive on a blood test for ANA, rheumatoid factor (RF), and/or anti-cyclic citrullinated peptide (anti-CCP) antibodies, but patients some do not. Blood tests may also show that the child is anemic (low red blood cell count), with elevated inflammatory markers such as ESR or CRP.
• Treatments: NSAIDs are initially given. Many children with polyarticular JIA will need DMARDs or biologic drugs to control symptoms and achieve remission. As with the other types of JIA, physical therapy to maintain proper joint function is critical.
• Possible complications: Patients should have regular eye exams to check for and prevent uveitis. Contractures and leg length discrepancies may occur. Children with polyarticular JIA may have involvement of their temporomandibular joints (TMJ), which may cause jaw problems such trouble chewing and an abnormally small chin. They may also have arthritis in their cervical spines, causing neck pain and other spinal issues.

Psoriatic JIA

Psoriatic JIA affects a few or multiple joints and may be accompanied by psoriasis. A family history of the disease may increase a child's risk of developing it.

• Who's affected: Children and adolescents, with a female predominance
• Symptoms: In addition to arthritis of multiple large and small joints, children may have swelling and redness of the fingers and toes (dactylitis), changes to the fingernails, and a red, scaly rash on the skin.
• Diagnosis: The child may test positive for ANA and/or a genetic marker called HLA-B27.
• Treatments: While NSAIDs are the initial therapy, many patients with psoriatic arthritis need a DMARD or biologic drug. Children with psoriasis should also be followed by a dermatologist and may need topical or other medications specifically for the rash.
• Possible complications: Patients should have regular eye exams to monitor for uveitis. In addition to the complications seen in polyarticular JIA, they are also at risk of sacroiliitis – inflammation of the sacroiliac joints in the pelvis, causing pain in the lower back, hips, buttocks, and legs. Treatment may need to be changed if they develop these symptoms to control discomfort and improve mobility.

Enthesitis-related JIA (ERA)

ERA involves inflammation of the entheses (where a tendon inserts into a bone), joints, and spine. This type of JIA is sometimes called “seronegative spondyloarthropathy.”

• Who's affected: Usually affects boys in late childhood and adolescence.
• Symptoms: Patients may have pain in one or more joints. Typically, the joints of the lower extremity, as well as the Achilles tendons, are involved. As in psoriatic arthritis, children may develop sacroiliitis.
• Diagnosis: Blood tests may be positive for the HLA-B27 genetic marker.
• Treatments: While some children can be treated with NSAIDs, many need biologic drugs or DMARDS to control symptoms and achieve remission.
• Possible complications: Patients are at risk for uveitis and should have periodic eye exams. The uveitis associated with ERA tends to be more painful and noticeable than that seen with other types of arthritis. ERA may also be associated with inflammatory bowel disease; if children have GI symptoms, they should see a pediatric gastroenterologist. Children with long-standing ERA may develop fusion of the joints in their pelvis and spine, leading to decreased mobility.

Systemic-onset JIA

Systemic-onset JIA is different from the other types, in that it causes more generalized inflammation throughout the body. It was formerly known as "Still’s disease."

• Who's affected: Children and adolescents
• Symptoms: Children with systemic JIA have fevers, often occurring daily around the same time. Typically, multiple joints are affected by swelling and pain, though sometimes fevers and other symptoms occur before the arthritis. Other symptoms include rashes that come and go, swelling of the lymph nodes, and problems with the lungs, heart, and blood.
• Diagnosis: Blood tests show elevated inflammatory markers, anemia, abnormal white blood cell counts, and liver enzyme elevations.
• Treatments: Systemic-onset JIA is treated with special biologic drugs that target certain chemical messengers involved inflammation (such as anakinra, canakinumab, and tocilizumab). Children with systemic-onset JIA also frequently need to take oral steroids for some period of time.
• Possible complications: In addition to joint damage from arthritis, patients are at risk for "macrophage activation syndrome" (MAS), a condition where the immune system becomes extremely overactivated and leading to an increased risk of bleeding, shock, and even death. MAS is a possible complication of systemic inflammatory diseases and requires hospitalization and immediate treatment. It is vitally important to control the symptoms of systemic JIA to prevent this potentially life-threatening situation. Lung disease, which can be fatal, is another rare complication of systemic-onset JIA.

Does juvenile idiopathic arthritis go away?

Some children may outgrow JIA, but others will continue to have ongoing arthritis into adulthood. Patients with the oligoarticular type are the most likely to outgrow it. With proper treatment, even children with chronic JIA can lead active lives without daily symptoms. In the short term, the goals of JIA treatment are to relieve discomfort, control inflammation, preserve function, and prevent deformities. Long-term goals include achieving and maintaining remission, minimizing the side effects of the disease and its treatment, monitoring growth and development, providing physical therapy as needed, and educating patients and their families.

Your child can live an active and productive life with JIA. Here are some tips to learn how:

• Maintain normal interactions with friends and family members as much as possible. Peer support is crucial. There are special summer camps for children with JIA, where they can be with other kids who are going through the same thing and enjoy fun activities designed just for them.
• Speak with your child's school about modifications such as help with writing, needing more time to complete exams, or getting a pass to use the school elevator. You can collaborate with teachers, social workers, and physical therapists to ensure your child gets what they need.
• Your child may be able to participate in sports except during times of active inflammation.
• Biologic drugs are often given by injection or IV (by vein), which some children are afraid of. Speak with your nurse or a child life specialist to help your child adjust to this method of treatment and get used to regular injections.
• JIA is a long-term challenging illness for patients and families. Don't be afraid to reach out for emotional support for yourself, your child, or anyone in your family. Support groups are available.
• Help your other children understand why your child with JIA needs more attention when they don't feel well, and what they can do to be helpful during this time.
• If your child is entering the teen years or going off to college and is taking medication, they may need to avoid drinking alcohol. Some medications are also dangerous to take during pregnancy, so sexually active teenagers will need to use appropriate birth control.

Your child’s pediatric rheumatologist is your partner in their care. Have open discussions with him or her about your concerns and how to best treat and support your child.

Posted: 2/9/2022

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