Reactive arthritis is an acute inflammatory aseptic arthritis that is preceded by an infectious process in genetically predisposed individuals. It has been associated with gastrointestinal or genitourinary infection. Reactive arthritis is rare in children. In this review, we present two index cases that need biologic treatment followed by a thorough review of reactive arthritis in children and adolescents with proposed treatment algorithm.

BACKGROUND: Familial Mediterranean Fever (FMF) is one of the most common hereditary auto-inflammatory diseases especially among Arabs, Armenians, Jews, and Turks characterized by recurrent attacks of fever, abdominal pain and arthritis.Whether the prevalence of ankylosing spondylitis (AS) is increased in FMF patients is a matter of debate. This review will summarize all the literature data relevant to this topic.
METHODS: We searched all the articles through PubMed and Embase databases from 1963 until 2017 addressing the relationship between AS and FMF patients.
RESULTS: The prevalence of AS among FMF patients is highly variable. However, a significant relationship was found to exist between MEFV gene mutations and AS. Most patients with coexistent MEFV gene mutations and AS were human leucocyte antigen B27 (HLA-B27) negative. The effect of these mutations on AS severity and prognosis was not significant.
CONCLUSIONS: Large based population studies are needed to further assess the existence of MEFV gene mutations among AS patients and their effect on the clinical course of the disease in addition to assessment of AS prevalence in patients with FMF.