Juvenile Psoriatic Arthritis - Causes, Symptoms, Diagnosis, and Treatment

Introduction

Arthritis is inflammation of joints causing pain and tenderness making day-to-day movement a hassle. Psoriasis is a skin disease that presents as itchy dry scaly skin especially visible on the joints such as knees, and elbows. Children may get arthritis which is called juvenile idiopathic arthritis, and psoriatic arthritis is a form of juvenile idiopathic arthritis that (rarely) affects children.

What Is Juvenile Psoriatic Arthritis?

Psoriatic arthritis is a condition with painful swollen joints along with skin rashes. It is most common among adults from the age of 30 but in rare instances, it can affect children and is usually starts with psoriasis before arthritis and seen to affect toes and fingers before elbows, ankles, knees, and lower back.

What Causes Juvenile Psoriatic Arthritis?

The exact cause of juvenile psoriatic arthritis is not known. Some studies show it could be a single or multifactorial involvement, such as immune system (a child’s immune system attacks its own cells and tissues), genetic (psoriatic arthritis runs in the family), or environmental factors (deficiencies).

What Are the Symptoms of Juvenile Psoriatic Arthritis?

Children may present with the following symptoms:

• Rashes - All over the skin or on extremities and joints.

• Dactylitis - Swelling of finger or toe- sausage-like appearance.

• Enthesitis - Swelling where tendons and ligaments attach to bone.

• Sacroiliitis - Swelling of the lower back.

• Spondylitis - Swelling of the spine.

• Swelling of joints (small and large joints).

• Uveitis - Swelling of the eye’s middle layer causing pain in the eye.

• Body ache and stiffness.

• Deformed joints due to prolonged condition of inflammation.

• Morning stiffness and tiredness.

• Redness of skin over the affected joints.

• Pitting of nails or onycholysis (splitting and breaking up of nails).

• Redness on nail beds or cuticles.

How to Diagnose Juvenile Psoriatic Arthritis?

Joint pain in children could be a natural sign of growth and development or any other health condition. A family history of psoriasis or psoriatic arthritis gives a possibility for juvenile psoriatic arthritis. A doctor may suspect juvenile psoriatic arthritis after a physical examination of the child. Additional tests help in diagnosing juvenile psoriatic arthritis. The tests are as follows:

• Complete Blood Count (CBC) - Low levels of red blood cells (anemia) and an increase in white blood cells and platelet levels may indicate a possibility for inflammation (swelling).

• Erythrocyte Sedimentation Rate (ESR) - It is a test done to determine the speed at which red blood cells settle at the bottom of a tube of blood. Red blood cells are heavier than the plasma and tend to settle at the bottom of the tube naturally. In case of inflammation, the red blood cells are heavier and settle down at a faster rate than normal. An increase in erythrocyte sedimentation rate indicates inflammation. It helps to monitor the progression of the condition as well; the higher the erythrocyte sedimentation rate, the higher the severity of inflammation.

• C- Reactive Protein Test - An increase in the levels of C-reactive protein indicates inflammation in the body.

• Antinuclear Antibody Blood Test - A test to check if a condition of the immune system attacking one’s own cells is present (autoimmune disorder. Antinuclear antibodies are specific antibodies that attack the nuclei of cells. Normally they may be present in blood minimally but an increase in antinuclear antibodies indicates an autoimmune disorder.

• Rheumatoid Factor - Rheumatoid factor is a protein; the presence in blood indicates an autoimmune disorder.

• HLA-B27- Human leukocyte antigen B27 (HLA-B27) is a protein present on the surface of white blood cells and its presence indicates a risk factor for juvenile psoriatic arthritis.

• Uric Acid - Uric acid is the body’s normal waste product. In the case of psoriatic arthritis, it is considered an increase due to dead skin cells and inflammation. Higher levels of uric acid are seen in juvenile psoriatic arthritis.

• Eye Test - The presence of uveitis.

• X-ray and MRI (Magnetic Resonance Imaging) - Help in diagnosis, but also to assess the extent and severity of the condition. The presence of diffuse soft-tissue swelling with overgrowth of bone in certain parts indicates inflammation that is unique to the pediatric skeleton. X-rays are also done to rule out the possibility of other conditions (for example, tumors) and also to monitor the progression of the disease.

How to Treat Juvenile Psoriatic Arthritis?

Treatment involves various measures to enable the child to do normal activities with ease or less discomfort. The first prime concern is the pain so medications are given to relieve the pain and the next is to prevent the progression of the disease.

The drugs used are as follows:

• For Psoriasis - Topical creams, lotions, or ointment containing medications like corticosteroids, coal tar (medicine to treat itching and scaling), and Calcipotriene (vitamin D3, which helps slow the skin cell growth) is given for the psoriatic rashes to heal.

• Antihistamines - Oral medication to prevent the itching sensation of the rashes.

• Nonsteroidal Anti-inflammatory Drugs (NSAIDs) - Ibuprofen, to reduce pain and inflammation.

• Corticosteroids - Prednisolone may be used initially to reduce the progression of the disease as biologicals, DMARDS are slow to start showing an effect on the body. Corticosteroids have severe side effects on growth and development when given to young children and hence must be used cautiously and under close monitoring.

• Disease-Modifying Anti-rheumatic Drugs (DMARDs) - DMARDs such as Methotrexate, prevent self-attack by the immune system and may also help the psoriasis rash. It is sometimes given in combination with NSAIDs or alone (if the child does not respond to NSAIDs).

• Biologicals - Abatacept, Adalimumab, Canakinumab, Etanercept, and Tocilizumab are new lines of immunosuppressant drugs that can help reduce or prevent inflammation in joints with lesser side effects than steroids.

• Physiotherapy and Regular Exercise - Done under supervision, to maintain the activity of the muscles and joints.

• UV Light Therapy - For psoriasis may help some children, but for some psoriasis may get worse.

• Heat and Cold Therapy - Heat therapy can help loosen stiff joints as they help to increase blood flow to the joints. Cold therapy reduces swelling and inflammation by reducing blood flow to the affected joints.

• Healthy Diet - Children may have less appetite and as a result, have deficiencies (calcium and minerals) that can affect bone health and development. Some children may put on excess weight due to physical inactivity which adds load on the arthritic bones and joints. A healthy diet along with calcium and vitamin D supplements is very important to maintain the bone health of arthritic children.

Conclusion

Juvenile psoriatic arthritis is rare in children and hence is often misdiagnosed. Delays in appropriate treatment measures may put the child at risk for life-long disabilities. Teamwork by a pediatrician and a rheumatologist (doctor of connective tissue, muscle, and joints), or a pediatric rheumatologist alone can help with early diagnosis and start with the needful treatment. With this, the child may get cured of the disease and relapse of the condition can also be prevented with the same.