Behçet’s disease (BD) is a polygenic condition with a complex immunopathogenetic background and challenging diagnostic and therapeutic concepts. Advances in genomic medicine have provided intriguing insights into disease pathogenesis over the last decade, especially into monogenic mimics of BD. Although a rare condition, paediatric BD should be considered an important differential diagnosis, especially in cases with similar phenotypes. Emerging reports of monogenic mimics have indicated the importance of genetic testing, particularly for those with early-onset, atypical features and familial aggregation. Treatment options ought to be evaluated in a multidisciplinary setting, given the complexity and diverse organ involvement. Owing to the rarity of the condition, there is a paucity of paediatric trials; thus, international collaboration is warranted to provide consensus recommendations for the management of children and young people. Herein, we summarise the current knowledge of the clinical presentation, immunopathogenetic associations and disease mechanisms in patients with paediatric BD and BD-related phenotypes, with particular emphasis on recently identified monogenic mimics.

Celiac Disease (CD) is an immune-mediated and gluten-related disorder whose prevalence is higher in children affected with other autoimmune disorders, including diabetes mellitus type 1, autoimmune thyroiditis, and others. As regards Juvenile Idiopathic Arthritis (JIA) and other pediatric rheumatic disorders, there is no clear recommendation for CD serological screening. In this review, we analyze all the available clinical studies investigating CD among children with JIA (and other rheumatic diseases), in order to provide objective data to better understand the necessity of CD serological screening during the follow-up. Based on the present literature review and analysis, >2.5% patients with JIA were diagnosed with CD; however, the CD prevalence in JIA patients may be even higher (>3–3.5%) due to several study limitations that could have underestimated CD diagnosis to a variable extent. Therefore, serological screening for CD in children affected with JIA could be recommended due to the increased CD prevalence in these patients (compared to the general pediatric population), and because these JIA patients diagnosed with CD were mostly asymptomatic. However, further research is needed to establish a cost-effective approach in terms of CD screening frequency and modalities during the follow-up for JIA patients. Conversely, at the moment, there is no evidence supporting a periodical CD screening in children affected with other rheumatic diseases (including pediatric systemic lupus erythematosus, juvenile dermatomyositis, and systemic sclerosis).

Familial Mediterranean Fever (FMF) is the prototype and most common autoinflammatory disease that is particularly frequent in populations originating from the Mediterranean basin. It is characterized by episodes of recurrent inflammation lasting 2–3 days. Colchicine is the mainstay therapy, which decreases the number of attacks and eventually prevents amyloidosis, the most worrisome complication of uncontrolled FMF. It is an autosomal recessive disease. The high rate of MEFV gene mutations in specific populations has been discussed as the result of an evolutionary advantage. Tel-Hashomer criteria were the first set of criteria primarily designed for adults. Recently, the Eurofever/PRINTO group has validated a new set of classification criteria for FMF, including clinical and genetic variables. Colchicine intolerance is an important problem and limits the ability to reach an effective dose. In these groups of patients, adding an alternative biological treatment (anti IL-1 agents) is recommended. Several tools such as FMF50, AIDAI, ADDI, ISSF and MASIF have been proposed to evaluate and quantify the disease activity and organ damage. Ongoing research should clarify the exact mechanisms causing FMF attacks and phenotypic variabilities between the patients; further translational research requires the implementation of proteomics and epigenetics signatures to elucidate the pathogenesis.