Behçet disease (BD) was first described by the Turkish dermatologist Hulusi Behçet in 1937 as a syndrome with oral and genital ulcerations and ocular inflammation [
1,
2]. It is defined as a rare multi-systemic inflammatory disease with unknown etiology and chronic recurrent pattern, characterized by oral and genital aphthosis/ulcers with ocular, skin, articular, vascular, gastrointestinal and/or central nervous system lesions. Furthermore, it has many clinical characteristics that are similar to inflammatory bowel diseases (IBD). BD is included both in vasculitis and auto-inflammatory disease classifications [
3]. It is considered a vasculitis with involvement of vessels of all kinds and sizes [
4] and it is defined as a multifactorial auto-inflammatory syndrome [
5]. The highest prevalence of BD has been reported in Japan, Iran, Turkey (Silk Route), more rarely occurring in Western countries. Usually, BD onset is found in young adults, around 20–35 years, with no difference between sexes, but a worse disease course in the male population. BD is rare in paediatric age and the prevalence is unknown. It is difficult to make diagnosis under 16 years due to the heterogeneous clinical picture, such as oral and genital ulcers, erythema nodosum, superficial thrombophlebitis, acne and arthritis [
6,
7]. Factors that contribute to the pathogenesis of BD include the host’s genetic profile and immune system, and environmental factors such as the gut microbiota. BD has an important genetic component, and thus the frequency of familial cases is around 10 to 50% [
8]. HLA-B51 is associated with BD, being predominant in affected males with a higher prevalence of genital ulcers, ocular and skin manifestations and decreased gastrointestinal involvement [
9]. Diagnosis of BD is based on clinical criteria. The most widely used diagnostic criteria for adult onset disease are from the International Behcet’s Study Group (ISG). In 2014, new criteria for BD diagnosis were proposed, called ICBD, that include two additional clinical criteria, neurological and vascular involvement, permitting diagnosis even without the presence of oral aphthous lesions which were considered mandatory in the previous ISG classification. An international expert consensus group, the pediatric BD (PEDBD), has recently proposed a new set of criteria for the classification of BD in children [
10]. PEDBD include the following features: recurrent oral aphtosis (at least 3 attacks/year), genital ulceration (typically with scar), skin involvement (necrotic folliculitis, acneiform lesions, erythema nodosum), ocular involvement (anterior or posterior uveitis, retinal vasculitis), neurological signs (with the exception of isolated headaches), vascular signs (venous thrombosis, arterial thrombosis, arterial aneurysm). All the clinical symptoms have the same importance (1 point) and three of them are required to classify a patient as having pediatric BD. Unlike the ISG and ICBD criteria, in PEDBD the pathergy test is not included. In children the symptoms are few to apply any classification. Because of the exiguity of clinical manifestations in the pediatric population, in most case the diagnosis is based on the physician’s experience. A substantial difference between the ISG and the PEDBD/ICBD criteria are that oral aphthosis is the mandatory criterion, while in the other two classification, it is possible to make diagnosis of BD even without the presence of oral aphtosis. The treatment of BD is difficult and is based on disease activity and severity including different medical therapies (corticosteroids, colchicine, immunosuppressive and biological drugs).