Still’s disease is responsible for inflammation of the joints in young children. It is the systemic form of what is called juvenile idiopathic arthritis (JIA), covering all inflammatory joint damage whose cause is unknown and which begins before the age of 16. Still’s disease has several names (systemic polyarthritis and systemic juvenile idiopathic arthritis) and accounts for 4-17% of JIA. (1) It can cause complications of articular, ophthalmological, renal, cardiovascular … and leave severe sequelae. Its prevalence is between 3,3 and 33 children per 100 and it is estimated that each year 000 to 0,11 affected children are born per 2,2. (100)

The so-called Edmonton criteria define JIA as the appearance of persistent arthritis in one or more joints for at least 6 weeks, the onset of the condition before the age of 16, and exclusion of other potential causes.

Symptoms of Still’s disease most often occur in children between the ages of 1 and 5 years. Its extra-articular symptoms clearly distinguish it from other forms of JIA: high fever and skin rashes. The diagnosis of Still’s disease is based on the presence of three clinical signs:

• A daily oscillating fever, with one or more temperature peaks equal to or greater than 39 ° C.
• Inflammation of one or more joints (it should be noted, however, that very rarely these arthritis may not occur for several months or several years).
• Other clinical signs may be observed in people with systemic arthritis: a rash on the skin during temperature peaks and an increase in the size of the lymph nodes (lymphadenopathy), the liver (hepatomegaly), or the spleen (splenomegaly) ).

The umbrella term “juvenile idiopathic arthritis” includes six identified diseases: systemic juvenile idiopathic arthritis, juvenile oligoarthritis, polyarthritis with and without rheumatoid factor, arthritis with enthesitis and psoriatic arthritis.

The term “idiopathic” means that the origin and mechanism of these conditions is unknown. According to the current state of knowledge, they result from a combination of genetic and environmental factors. Researchers have successfully identified changes in several genes that may influence the risk of developing juvenile idiopathic arthritis.

The majority of cases of juvenile idiopathic arthritis are sporadic. In other words, they occur in people with no family history. But rare cases have been reported within families, according to a still uncertain mode of transmission.

The first step in the treatment of Still’s disease is to give aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) for 1 to 4 weeks to watch the symptoms progress. Their possible side effects should be carefully monitored. In the event of insufficient efficacy or hepatic toxicity of NSAIDs, corticosteroid therapy is used under very specific conditions.

In adulthood, half of those affected are cured, while the other half still suffers from arthritis, accompanied or not by extra-articular symptoms (fever and rashes). 20% of them retain significant sequelae, such as growth retardation and disability linked to joint damage. (2)