Precision medicine (PM) is changing the scope of allergy diagnosis and treatment. An in vitro IgE assay, a prototype PM method, was developed in the sixties and has garnered increasing interest because of the introduction of recombinant components in the test. More recently, microarrays of allergen components have significantly improved the ability to describe the IgE profile. Aim of this study was to evaluate the characteristics of the newly developed Allergy Explorer (ALEX), a macroarray containing both extracted "whole" allergens and molecular components. This method allows the acquisition of an IgE profile comprising 282 reagents (157 allergen extracts and 125 components), resulting in the widest screening of potential allergens available. Sera from 43 patients with allergies were assayed with ALEX and then with ImmunoCAP ISAC. The results of the two tests were compared, and the consistency of the molecular results with the presence of IgE in the relevant extract was also evaluated. A good correlation between ISAC and ALEX was observed. The ALEX results for second-level tests (i.e., specific IgE to complete extracted allergens) were consistent with the results obtained for the relevant components. Despite differences in the methodology, the IgE profiles detected for molecular allergens by ALEX and ISAC were very similar. The differences were mainly related to the lower dynamic range of ALEX and to the use of a CCD inhibitor in the first incubation phase, which reduced the binding of IgE to CCD, as represented in the extracted allergens and components. Based on our findings, ALEX is a novel tool for describing the IgE profile in a PM setting, where the IgE assay must be performed on many allergens and components. In particular, polysensitized patients and patients with pollen-food syndrome will have a real advantage due the combination of the second and third levels of allergy diagnostics in the same chip.

Background: Urticaria is a disorder affecting skin and mucosal tissues characterized by the occurrence of wheals, angioedema or both, the latter defining the urticaria-angioedema syndrome. It is estimated that 12–22% of the general population has suffered at least one subtype of urticaria during life, but only a small percentage (estimated at 7.6–16%) has acute urticaria, because it is usually self-limited and resolves spontaneously without requiring medical attention. This makes likely that its incidence is underestimated. The epidemiological data currently available on chronic urticaria in many cases are deeply discordant and not univocal, but a recent Italian study, based on the consultation of a national registry, reports a prevalence of chronic spontaneous urticaria of 0.02% to 0.4% and an incidence of 0.1–1.5 cases/1000 inhabitants/year.Methods: We reviewed the recent international guidelines about urticaria and we described a methodologic approach based on classification, pathophysiology, impact on quality of life, diagnosis and prognosis, differential diagnosis and management of all the types of urticaria.Conclusions: The aim of the present document from the Italian Society of Allergology, Asthma and Clinical Immunology (SIAAIC) and the Italian Society of Allergological, Occupational and Environmental Dermatology (SIDAPA) is to provide updated information to all physicians involved in diagnosis and management of urticaria and angioedema.

Cross-reactivity among Hymenoptera venoms is an important issue when prescribing venom immunotherapy (VIT). Using all venoms eliciting a positive response results in treatment excess and unjustified cost increase. The first in vitro method that helped to identify the really causative venom was RAST-inhibition, but in latest years also molecular allergy (MA) diagnostics, that detects specific sIgE to single venom allergens, was introduced. We compared the two methods in patients with double sensitization to Vespula spp. and Polistes spp. Fifty-four patients with anaphylactic reactions to Hymenoptera stings and positive results to skin tests and sIgE measurement with whole venom from Vespula spp. and Polistes dominula were included in the study. Sera from all patients were analyzed by CAP-inhibition (Thermo Fisher Scientific, Uppsala, Sweden) and MA diagnostics with recombinant Ves v 1, Ves v 5 and Pol d 5. By the data obtained from MA technique, VIT would have been prescribed to 7 patients for Polistes, to 6 for Vespula, and to 41 for both venoms. With the data from CAP inhibition, it would have been a prescription to 15 patients for Polistes, to 28 for Vespula, and to 11 for both venoms. A good concordance between the results of MA and CAP-inhibition was found only when the value in kU/l of Ves v 5 were about twice those of Pol d 5, and vice versa. These findings suggest that in the choice of the venom to be used for VIT CAP-inhibition remains a pivotal tool, because the significance of in vitro inhibition is definite and provides a diagnostic importance higher than MA in patients with positive tests to both Vespula and Polistes spp.

Eosinophilic esophagitis (EoE) is a multifaceted disease characterized by a wide heterogeneity of clinical manifestations, endoscopic and histopathologic patterns, and responsiveness to therapy. From the perspective of an effective approach to the patient, the different inflammatory mechanisms involved in the pathogenesis of EoE and biologics, in particular monoclonal antibodies (mAbs), targeting these pathways are needed. Currently, the most relevant is dupilumab, which interferes with both interleukin (IL)-4 and IL-13 pathways by binding IL-4 receptor α, and is the only mAb approved by the European Medicine Agency and US Food and Drug Administration for the treatment of EoE. Other mAbs investigated include mepolizumab, reslizumab, and benralizumab (interfering with IL-5 axis), cendakimab and dectrekumab (anti-IL-13s), tezepelumab (anti-TSLP), lirentelimab (anti-SIGLEG-8), and many others. Despite the undeniable economic impact of biologic therapies, in the near future, there will be room for further reflection about the opportunity to prescribe biologic agents, not only as a last-line therapy in selected cases such as patients with comorbidities involving common pathways. Although recent findings are very encouraging, the road to permanent success in the treatment of EoE is still long, and further studies are needed to determine the long-term effects of mAbs and to discover new potential targets.

Component resolved diagnosis (CRD) allows to precisely identify the sensitization to specific molecules of a given allergenic source, resulting in an important improvement in clinical management, particularly of polysensitized subjects. This will end in the correct prescription of allergen immunotherapy (AIT) for respiratory allergy and in adequate avoidance diets or prescription of self-injectable adrenaline in food allergy. The aim of this multicenter, real life study is to evaluate the percentage change of the diagnostic-therapeutic choice in polysensitized patients with respiratory allergy and in patients with food allergy, after using CRD compared to a first level diagnosis, along with an economic analysis of the patient's overall management according to the two different approaches. An overall number of 462 polysensitized patients, as suggested by skin prick tests (SPT), and with clinical symptoms related to a respiratory (275 pts) or food (187 pts) allergy, were recruited. All patients underwent CRD for specific IgE against food or inhalant recombinant molecules, which were chosen according to medical history and positivity to SPT. The first diagnostic-therapeutic hypothesis, based only on medical history and SPT, was recorded for each patient while the final diagnostic-therapeutic choice was based on the results from CRD. The rate of change of the diagnostic-therapeutic choice from the first hypothesis to the final choice was statistically evaluated. The economic impact of CRD on the overall management of the allergic patients was analyzed to evaluate whether the increase in the diagnostic costs would be compensated and eventually exceeded by savings coming from the improved diagnostic-therapeutic appropriateness. An approximate 50% change (k index 0.54) in the prescription of AIT for respiratory allergy as well as a change in the prescription of self-injectable adrenaline (k index 0.56) was measured; an overall saving of financial resources along with a higher diagnostic-therapeutic appropriateness was also detected. There is moderate agreement concerning prescription of AIT and self-injectable adrenaline before and after performing CRD: this highlights the usefulness of CRD, at least in polysensitized patients, in indicating the risk assessment and therefore the correct therapy of respiratory and food allergy, which results in a cost-saving approach.

Background: The introduction of component-resolved diagnosis was a great advance in diagnosis of allergy. In particular, molecular allergy techniques allowed investigation of the association between given molecular profiles and clinical expression of allergy. We evaluated the possible correlation between the level of specific IgE (sIgE) to single components of Phleum pratense and clinical issues such as the severity of allergic rhinitis (AR) and the presence or absence of asthma. Methods: The study included 140 patients with rhinitis and/or asthma caused by sensitization to grass pollen. sIgE to Phl p 1, Phl p 5, Phl p 7, and Phl p 12 from Phleum pratense were measured, and the correlation between the stage of AR according to Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines and the presence of asthma was studied by multivariate logistic regression in terms of sIgE and ARIA stage, while univariate logistic regression was used for IgE and a dichotomic classification of asthma as present or absent. Results: Ten patients had intermittent AR, 48 had mild persistent AR, and 82 had severe persistent AR. Asthma was present in 86 patients and absent in 54. A significant correlation was found between severe persistent AR and presence of asthma (p < 0.01). The only significant correlation between clinical data and sIgE values was that of low values of sIgE to Phl p 5 and absence of asthma (p < 0.01). Conclusions: This preliminary finding suggests that low values of sIgE to Phl p 5 are correlated with the absence of asthma in patients with grass-pollen induced allergy. The data, provided they are confirmed by further studies, could be useful when selecting patients who are candidates for allergen immunotherapy, since a higher risk of asthma could be used as a selection criterion for using this approach.