The advent of biological drugs has opened up new therapeutic possibilities in the field of eosinophilic gastro-intestinal diseases (EGIDs). EGIDs are chronic inflammatory diseases of the gastrointestinal tract unrelated to drugs or infections, and eosinophilic esophagitis (EoE) is the most frequent form. EGIDs are complex disorders, which pathogenesis is still partially unknown. The diagnosis of EGIDs relies on the combination of different data, such as clinical manifestations, laboratory tests, endoscopic, and histological data. The gold standard at present is the histological examination obtained from biopsies under endoscopic guidance, but the diagnostic criteria for each disorder are still not fully defined, and few clinical scores are validated, for all these reasons, conducting clinical trials on EGIDs is challenging. The dietary approach remains currently a first-line treatment, despite its efficacy being influenced by patients’ compliance. Exclusion diets, nevertheless, involve potential nutritional deficiencies. Two of the pivotal pharmacological therapies for the treatment of EGIDs are proton pump inhibitors (PPIs), especially for EoE, and systemic or topical steroids. Long-term corticosteroid therapies are, however, associated with even severe side effects, so steroid-sparing therapies are needed to achieve the same results, in the last years monoclonal antibodies have been studied. To date, dupilumab is the only approved biological drug for EoE therapy, but many others are currently being tested in clinical trials also for the other forms of EGIDs. This work presents a complete review of the role of biological drugs in EGIDs to date, systematically structured by pathology.

A case report of fish allergy is exposed. The responsible allergen was fish collagen, and there was no sensitization to parvalbumin (main fish allergen). The patient acquired collagen sensitization by occupational exposition, not by ingestion.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a multiorganic syndrome that affects the cardiovascular, neurologic, renal, and gastrointestinal systems with an incidence ranging from 0 case to 67 cases per one million person-years, and its pathophysiology remains unknown. It is believed that genetic factors, the environment, and changes in immune system function contribute to the development of EGPA, overlapping the immune mechanisms of vasculitides and the pathologic mechanisms in eosinophilic syndromes. This disease is commonly divided into two phenotypes depending on the presence of antineutrophil cytoplasmic antibodies (ANCA). ANCA-positive patients usually have more vasculitic manifestations like peripheral neuropathy, purpura, renal involvement, and biopsy-proven vasculitis. The keystone of EGPA therapy is systemic corticosteroids (CS) as monotherapy or in combination with other immunosuppressive treatments, and recently the efficacy of eosinophil-targeted biotherapy, anti-interleukin-5 (IL-5), has been shown to be efficacious in EGPA. Although this phenotype/phase distinction has not yet had an impact on the current treatment strategies, emerging targeted biotherapies under evaluation could lead to a phenotype-based approach and personalised treatment regimens for EGPA patients. The present review describes the new therapeutical approaches with biological drugs for EGPA.