Eosinophilic esophagitis: Pathophysiology, diagnosis, and management.

Eosinophilic esophagitis (EoE) is a multifactorial esophageal inflammation, with a genetic predisposition, which combines a deficient esophageal mucosal barrier, an abnormal immune reaction to environmental allergens mediated by Th2 interleukins, immediate esophageal lesions and dysmotility, with secondary remodeling and fibrosis. Symptoms include reflux, abdominal pain, and food impaction, with a variation according to age. Fibroscopy shows major and minor endoscopic and histologic criteria, with a mucosal count≥15 eosinophils/high power field (Eo/hpf). A new entity has been defined, where gastroesophageal reflux disease (GERD) and EoE share responsibility: the PPIs-sensitive form of EoE (PPI-REE). Children with fibroscopy showing≥15 Eo/hpf need a second endoscopy following 8 weeks of PPI treatment. EoE has a strong association with other atopic disorders. Allergy testing (specific IgE blood test and skin prick tests [SPTs]) identifies patients at risk of anaphylaxis (14.8% of cases). The dietary therapy is based on a 4- to 12-week elimination test followed by endoscopy to check the disappearance of eosinophilic infiltration. The "dietary approaches are the amino acid-based formula, the allergy testing-based targeted diet, and the six-food elimination diet (empirical elimination of milk, wheat, soy, eggs, peanut/nuts, and fish/seafood). A recent first-line trial elimination of milk has been suggested, with wheat as a second elimination, if necessary. Dietary therapy allows remission and catch-up growth in 65% of cases. Swallowed topical steroids (budesonide in viscous gel or fluticasone propionate for nebulization) are an alternative, for which efficacy varies according to clinical and/or histological criteria and with relapses occurring at dosage tapering. Their use may be restricted by side effects, such as oral and/or esophageal candidiasis. The impact on long-term bone health and growth is unknown. Maintenance therapy is not standardized and is team-dependent, combining or not elimination diets and long-term steroids. The long-term risk of EoE is esophageal stenosis (25%) and endoscopic dilation may be repeated. Biotherapies have shown isolated histological improvement without significant clinical efficacy.

[Kikuchi-Fujimoto disease mimicking malignant lymphoma in adolescents]. / La maladie de Kikuchi-Fujimoto ; un diagnostic différentiel méconnu du lymphome chez l'adolescent.

Kikuchi-Fujimoto disease, also known as histiocytic necrotizing lymphadenitis, is a rare cause of lymphadenopathy in children. This benign disease can mimic lymphoma and misleads doctors. It was first described in Asia, where it occurred especially in young women. Recent publications show that it can also affect teenagers and young adults in Caucasian populations. The pathophysiology remains unknown. Three hypotheses have been raised for this disease: the role of viruses (in particular HHV-8), genetic predisposition (two alleles in HLA class II genes were found more frequently in patients with Kikuchi disease), and an autoimmune cause because of the correlation with lupus erythematosus. Few cases have been reported in Europe so far. In this article, we report three cases of Kikuchi disease observed in less than 2 months in a single hospital in France. All three patients were teenagers who presented with lymphadenopathy, either isolated or combined with fever, weakness, and weight loss. In all of them, the hypermetabolic activity of the lymph node on the PET scanner misled us to suspect lymphoma. The diagnosis of Kikuchi disease was finally made, for all patients, after 2 weeks in the hospital based on lymph node biopsy. Based on this report, we highlight that early biopsy in presence of lymphadenopathy can avoid unnecessary extensive investigations. Moreover, in this rare disease, it is very surprising to come across three cases that are not family-related, in such a short period of time. This strengthens the hypothesis of the possible implication of an environmental factor in the pathophysiology of Kikuchi disease.