Juvenile idiopathic arthritis (JIA)

Introduction

Juvenile idiopathic arthritis (JIA) is a group of autoimmune conditions that cause your child’s joints to become inflamed or swollen. Autoimmune conditions are conditions where the immune system fights the body’s healthy cells instead of illness and infection.

Children with JIA can have general symptoms, including:

• swelling or redness around their joints
• a limp when walking
• not wanting to use an arm or a leg
• crawling instead of walking
• feeling generally unwell
• slow growth
• not wanting to eat
• being more tired than usual
• feeling irritable
• being more clumsy than usual.

Children will not usually have pain.

There are several types of JIA, which are grouped by:

• how many joints are affected
• whether there is fever, rash, or inflammation of internal organs.

Five common types of JIA and their symptoms are:

1. oligoarthritis – when four joints are affected, usually the knees and ankles
2. polyarticular – when five joints are affected, including wrists, ankles, fingers, toes, hips, knees, neck, and jaw
3. systemic onset JIA – affecting the joints and causing inflammation all over the body with fever, rashes, aches, and swollen glands
4. enthesitis-related arthritis – inflammation of the ligaments and tendons, which are the tissues that attach your child’s bones to the joint
5. psoriatic arthritis – affecting joints and causing a red, scaly skin rash.

Some types of JIA can also cause uveitis. Uveitis is when the eyes become inflamed, red, and painful.

Your child will be referred to a specialist, called a rheumatologist, who looks after the joints and muscles.

Some children with JIA will not have any inflammation during a flare-up of symptoms, which can make it hard to diagnose.

The doctor will order tests to rule out other health conditions causing the symptoms.

Tests can include:

• a physical check to see how your child moves
• blood tests to check for damage to the muscles
• MRI scans to check how the muscles look.

Your child’s doctor will let you know which tests are needed depending on your child’s symptoms. 

Symptoms in JIA can come and go and may only appear briefly because of an injury, infection, or allergy. This can mean that diagnosing JIA takes a long time.

Knowing which type of JIA your child has will help their doctor to understand how to treat it.

JIA is a condition that responds well to treatment and careful management. Your child’s doctor will aim to:

• reduce inflammation
• prevent long-term damage to bones and joints
• improve your child’s ability to move and do their everyday activities.

JIA is a long-term illness, but it can get better and sometimes go away as your child grows into an adult.