[An atypical case of systemic juvenile idiopathic arthritis].

The systemic juvenile idiopathic arthritis (SJIA) is a rare, auto-inflammatory and chronic childhood disease. Arthritis of at least one joint is associated with a daily fever lasting more than two weeks and with one of the following signs: lymphadenopathy, hepatomegaly, serositis, or skin rash. Systemic symptoms are often initially preponderant, in the absence of arthritis than can occur weeks or months later. The typical rash is maculopapular discrete, fleeting and dew. We present an unusual SJIA case, where the rash, like urticaria, presents itself as persistent, itchy hives. An arthritis of the elbow appeared only one month after the onset of the disease. This case illustrates the difficulty of diagnosis, which can only be made after the exclusion of more common (infectious) and severe (hematooncology) diseases.