Introduction
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.

What are the complaints?
In infants and toddlers it may be difficult to elicit symptoms. Inability to use a limb or part of the limb, excessive crying when the affected portion is touched, limp while walking may all be the initial symptoms. Often these are persistent over a period of few weeks. Along with this there could be low grade to high-grade fever, lack of appetite and loss of weight. Arthritis although primarily involves the joints can present with symptoms and signs of other system involvement.

What are the other systems that can be involved?
Almost any other system can be involved. However it is important to note that only a proportion and not all patients with juvenile arthritis get all the various manifestations mentioned. The organ systems that can be involved often depend on the type of arthritis. This will be dealt with when individual disorders are discussed.

What are the 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

1. Polyarthritis (5 or more joints involved),
2. Pauci-arthritis (< 5 joints involved) and
3. 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), heart burn 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.
Polymyositis / 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.

Last updated on 24-12-2001