What is the chronic inflammatory disease of the joints affecting children and young people known as juvenile idiopathic arthritis?
Juvenile idiopathic arthritis, or JIA for short, is an umbrella term for chronic inflammatory diseases of the joints in children and young people. There are various forms taken by the disease, varying in terms of the number and pattern of the joints affected. In some patients only a few joints are inflamed to begin with. This is the oligoarthritic form of JIA, from the Greek ‘oligos’ = few. Often the large joints, like those of the knee and ankle, are affected. In the active phases of the disease the joints are swollen, hot and painful, and their mobility is seriously restricted. In order to relieve the strain on the joints, patients typically adopt incorrect postures in compensation. The performance of young patients is impaired; they give the impression of being exhausted and run down.
In the ‘polyarthritic’ form of the disease (from the Greek ‘poly’ = many), a greater number of joints are affected. Mostly the smaller joints, like the finger and wrist joints, are inflamed. Sometimes changes are noticed in areas that are generally associated with other rheumatic conditions. Some distortions of the fingers resemble those that occur in rheumatoid arthritis with adults.
The restricted finger movement has the consequence that in certain phases of child development it is very much more difficult for the child to learn new skills. This shows for example in the grasping of objects, as well as in connection with writing.
If the child suffering from the disease has an inflammation of the joints in conjunction with psoriasis, or if psoriasis is found in a closely related member of the family, this falls under the heading psoriatic arthritis. In about fifty percent of cases the inflammation of the joints appears first, in the other fifty percent it is the psoriasis that first manifests.
If not only the joints but also the tendon inserts (entheses) are inflamed, the condition is referred to as enthesitis-associated arthritis. 70 to 80 percent of those affected are boys.
The systemic form of JIA differs fundamentally from other forms of the disease. As well as inflammation of the joints, recurrent attacks of fever are experienced – typically with one to two peaks every day – along with skin rashes. The organs may also be involved.
Some patients with JIA will develop an inflammation of iris. This usually makes an insidious appearance, and then comes to be noticed through such symptoms as pain, sensitivity to light and red eyes.
Around 15,000 young people aged up to 16 are affected by juvenile idiopathic arthritis in Germany, with around 750 to 1000 new cases occurring every year. This makes juvenile idiopathic arthritis the commonest chronic inflammatory rheumatic disease in childhood. It is more common in girls.
The causes of juvenile arthritis are still largely unknown. We can assume, however, that the crucial factor is an uncontrolled reaction of the immune system. As a defence mechanism, the immune system is responsible for detecting dangerous pathogens, foreign bodies and toxic substances and systematically destroying them. The body’s own substances and surrounding tissue are generally recognised and tolerated by the cells of the immune system. But if cell to cell communication is disrupted, the destructive activity of the immune system will be unleashed on the bodily tissue as well, leading to an inflammatory reaction.
The Deutsche Gesellschaft für Kinder- und Jugendrheumatologie [German Society for Rheumatology in Children and Young People] recommends a balanced diet with a sufficient supply of energy foods, vitamins, fibre and trace elements. At all events a one-sided diet should be avoided. The majority of children and young people eat more meat and sausage, and less fruit and vegetables, than is recommended. In all cases care should be taken to ensure that the diet includes sufficient calcium, as appropriate at this age.
Patients can lose a considerable amount of weight. Parents therefore need to ensure that their child does not lose weight to an excessive degree.
Adolescent patients should not be subjected to additional strain. The family should endeavour to keep life as normal as possible.
To diagnose the disease, the doctor will ask about the nature, start and progress of the current symptoms. Indications of triggering events are important; other cases of inflammatory rheumatic disease in the family history are also significant.
A thorough physical examination is carried out, paying attention to every painful joint. The doctor will also take into account any changes to the skin, and check for eye involvement.
The following diagnostic procedures are available:
- Physical examination
- Blood tests
- X-rays
- Ultrasound
Blood tests yield information about the current progress of the inflammation. The blood values reveal the functional capability of the inner organs, and support more exact predictions about the further course of the illness.
In addition, doctors use imaging procedures in order to learn more about the state of the inflamed joints and detect any damage. X-ray and ultrasound examinations are suitable methods for the purpose.
When patients are still in an early stage of child development or younger, it is sometimes not easy to diagnose a case of juvenile idiopathic arthritis. Only from a certain age upward can children speak about the symptoms in their own words and provide a detailed description.
In the initial stages, the symptoms of juvenile idiopathic arthritis are similar to those of other rheumatic diseases. A paediatric rheumatology consultant has specialist knowledge of the specific features of diagnosis, and will be able to initiate and supervise a form of therapy that is effective and will be well tolerated.
Medicaments used for the treatment of juvenile idiopathic arthritis include first and foremost non-steroidal antirheumatics, known as NSARs for short (e.g. with Diclofenac as the active substance), ‘disease-modifying antirheumatic drugs’ or DMARDs, and corticoids (e.g. with the active ingredient Prednisolon).
NSARs help to relieve pain in the joints, abating swellings and fever. They are rapid in their effects – an improvement is generally felt within hours or days. When the progress of the disease is not too severe, this therapy on its own is often sufficient. But if the disease progresses chronically, DMARDs will be needed as well. These have a regulatory effect on the misdirected immune system, and can alleviate and prevent the advance of the disease.
DMARDs include e.g. the active substances methotrexate, leflunomide, sulfasalazine, azathioprine and antimalarial drugs. Methotrexate is currently regarded as the gold standard drug for the treatment of JIA.
As a third drug-based approach to treatment, corticoids have proved effective. They act powerfully to check the inflammation, and can either be taken in tablet form or injected directly into the inflamed joint. These substances have a rapid effect in relieving pain, and check the inflammation in the short term. They do not affect the actual progress of the disease, however. With most patients, corticoids are used for as long as it takes to reduce the pain and the inflammation significantly. After that the dose will be reduced, or the drug phased out completely.
Apart from drug-based treatment, non-drug-based approaches are also a valid alternative. First and foremost these include remedial gymnastic exercises, physical forms of therapy, patient training courses and aids such as orthopaedic insoles and the like.
Remedial gymnastics helps to preserve the patient’s mobility, prevents stiffening of the joints, and encourages the patient to avoid bad posture, compensatory movements and inappropriate movement habits. When changes of this nature have already taken place, it tries to correct faulty patterns with the aim of restoring normal functioning.
