Systemic: the most serious but the least common, causing inflammation of internal organs including the heart, liver, spleen and lymph nodes.

Paediatric rheumatism is caused by the body's immune system attacking its own healthy cells and tissues. It can be inherited and affects more women than men.

The wide and varying range of symptoms make the disease difficult to diagnose and can delay treatment, which can cause further destruction. The following symptoms may appear during flare-ups or may be chronic and continuous:

Swollen, stiff and painful joints, especially when waking

High fever and rash

Swollen lymph nodes

Inflamed eyes (detectable only by an ophthalmologist)

Warm, red, inflamed joints

Fatigue

Decreased appetite and weight loss or slow growth.