JUVENILE RHEUMATOID ARTHRITIS (JRA)
Last Updated : 12/6/2010
Dr. Gurmeet Mangat
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Musculo-skeletal pain is not uncommon in children. Though commonly this is due to a benign process called "growing pains", arthritis can afflict children as well. Arthritis (inflammation in the joints) has been described in children as young as 1 year. For the sake of classification, arthritis occurring in the age groups up-to 16 years is called "

Juvenile Arthritis

".

Almost all the types of arthritis that have been described in adults have also been described in children. In all there are easily more than 50 different types of arthritis that can develop in children. This communication discusses the presentation and principles of management of the common varieties.

It is found that JRA occurs to the extent of 30% in some population studies. It reportedly occurs in 1 in every 10,000 children every year. Although there are good descriptive series from different part of the country, there is a lack of accurate epidemiological data. The age of onset is often below 5 years and girls tend to be affected twice as frequently as boys.

Common forms of juvenile arthritis
The most common form of juvenile arthritis is called juvenile idiopathic arthritis. This in-turn is further subdivided into 3 subgroups:
- Polyarthritis (5 or more joints involved),
- Pauci-arthritis (< 5 joints involved) and
- Systemic onset disease (also called Still's disease)
In these forms of arthritis, joint involvement is the predominant mode of presentation. Low grade fever weight loss and loss of appetite can accompany the first 2 forms of arthritis. Still's disease often presents with high grade swinging fever, short-lived reddish rash (often with the fever swing) and, in a proportion of patients, other organ involvement. Pleural effusion (fluid in the covering membranes of the lung), pericardial effusion (fluid in the covering membranes of the heart), ascites (fluid in the covering membranes of the intestine), enlargement of the liver/spleen, etc. are the organ systems that can be involved.

Systemic lupus erythematosus is a form of arthritis characterized by high-grade fever, facial rash, loss of hair, oral ulcers and joint pains. Diagnosing this entity is important, as other system involvement is common and troublesome. Anemia, low platelet count with bleeding, neurological involvement and kidney involvement can occur.

Scleroderma is characterized by tightening of skin (fingers & generalized), blue fingers especially when exposed to cold (called Raynaud's), heartburn with or without difficulty in swallowing (due to involvement of the food pipe-esophagus) and joint pains. Lung involvement (called interstitial lung disease), pulmonary hypertension and rapid increase in blood pressure (called accelerated hypertension) are important complications of this condition.

Polyarthritis / dermatomyositis are conditions characterized by inflammation in the muscles. Patients present with painful weakness in the muscles. In addition, patients with dermatomyositis have a rash on the face, trunk and typically over the knuckles. Lung involvement (interstitial lung disease) can occur in a proportion of patients.

Effect of climate and food have on arthritis
There is no scientific proof to say that either hot/cold weather is the cause of arthritis. However sudden changes in temperature especially from hot to cold could worsen a pre-existing arthritis. Further, since the level of activity goes down during cold weather the joint stiffness increases. When the disease is well-controlled with appropriate medications, one finds no relationship between the weather and the joint disease.

The kind of food eaten by and large does not affect the joints. In fact when the arthritis is active, there is loss of weight and appetite. Hence, there is no logic in doing any kind of dieting/food restriction. Less than 5% of children with arthritis have what is termed food allergy. This could be allergy to any kind of food including wheat-based food like chappati/bread. These patients are told to avoid only that specific food.

Causes
The exact cause of these disorders has not yet been clearly defined. However, it is thought that in the presence of genetic predisposition and undefined environmental insult perpetuates a chronic inflammation causing the arthritis.

Types of JIA
It should be emphasized that although these disorders come under the broad heading of arthritis depending on the disease, the predominant affliction may be related to other organ systems rather than the joints. Table 1 describes the common forms of arthritis encountered and their main modes of presentation.

Type of ArthritisModes of joint involvementExtra-articular features (% : occurs only in a proportion of patients)
Juvenile idiopathic arthritisPersistent arthritis of more than 6 weeks of one or more jointsFever, intermittent rash, subcutaneous nodules, other organ system involvement ;
Juvenile systemic lupus erythematosusArthralgias and arthritisMalar rash, oral ulcers, hair loss, fever, loss of appetite & weight. Other organ system involvement importantly hematological, neurological and the renal may be involved.
Juvenile myositisJoint pains more than arthritis.Patient complains more of muscle pain with weaknessDiffuse rash, rash around the eyes,involvement of other organ systems importantly lung and neurological
Juvenile sclerodermaArthralgia or ArthritisRaynaud's phenomenon, sclerodactyly, pitted scars, finger tip ulcers, interstitial lung disease
Juvenile vasculitis
  
Henoch Schonlein PurpuraArthralgia / arthritisRed palpable rashes especially in the lower limbs. Haematuria and bleeding per rectum
Kawasaki's diseaseArthritis / arthralgiaMucocutaneous lesions & lymphadenopathy. Coronary vascular involvement.
Other vasculitisArthritis / arthralgiaLung/kidney/sinus involvement in Wegener's granulomatosis. Eosinophilia with lung involvement in Churg Strauss disease. GI/Kidney/nerve involvement in polyarteritis nodosa. Kidney / nerve involvement in microscopic polyangiitis.



Although there are many different types of juvenile arthritis, a logical process of assessment can often lead to proper diagnosis and management. The mode of onset, type of joint involvement, the other associated organ system involvement and the attendant systemic features like fever, rash, weight loss etc. can all help in ascertaining the diagnosis.

Juvenile idiopathic arthritis:

Here, the dominating clinical feature is painful swelling and stiffness in the joints. Depending on the number of joints involved this disease is further divide into 3 main categories. Pauci-articular (if < 4 joints are involved), polyarticular (> 4 joints are involved) and systemic onset disease (high-grade fever, rash and often other organ system involvement).

Juvenile systemic lupus erythematosus: The disease is characterised by fever, rash on the face, hair loss, oral ulcers and arthritis. Kidney disease is an important complication, occurring in a proportion of patients.

Juvenile myositis:

Here, the child presents with muscle pains, weakness and diffuse rash. The rash can also be characteristically localized to the eye lids and knuckles.



Contributor Information and Disclosures

Dr. Gurmeet Mangat
Consultant Rheumatologists, P.D.Hinduja Hospital, Mumbai


First Created : 4/9/2001

References

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