Background: Worldwide data on epidemiology of anaphylaxis are limited, mostly due to the difficult recording of all cases. The aims of the study are to determine anaphylaxis frequence to a general E.D. before and during COVID-19 pandemic, its association with demographic and clinical characteristics. Methods: This is a retrospective study analysing clinical records from a general E.D. of Milan in two periods before (2018-2019) and during the COVID-19 pandemic (2020-2021). The analysis regarded demographic data, comorbidities, chronic therapies, causes, severity and adrenaline use. Globally data were assessed to find predictive risk factors for a severe reaction. Results: The frequence of anaphylaxis remained stable, (120/104129 = 0.12% in 2018-2019 and 72/66720 = 0.1% in 2020-2021). No differences in the occurrence of anaphylaxis were found in sex and in the mean age. The main causes of anaphylaxis were food (2018-2019: 53% vs 2020-2021: 51%) and drugs (2018-2019: 27% vs 2020-2021: 33%). Hymenoptera stings had a low occurrence and unidentified trigger was about 15% in each period. The severity of anaphylaxis had a similar distribution in the two-year periods. Gender, cardiovascular diseases, food allergy, drug allergy and Hymenoptera venom allergy did not influence the severity. A positive correlation was found with an increase in the mean age, especially in patients aged 50 or more (p<0.001). Angiotensin II receptors blockers, β-blockers, diuretics and proton pump inhibitors were associated with increasing severity (p<0.01). Conclusion: The anaphylaxis frequency in E.D. was not affected by the COVID-19 pandemic. Food anaphylaxis remained the most important cause of admission to the E.D. in our urban area. More studies are necessary to estimate the real incidence of all anaphylactic reactions.

We describe the case of a patient with a diagnosis of rheumatoid arthritis experiencing a mucocutaneous delayed reaction to golimumab. Anyway, there is no consensus regarding the best management of delayed reactions to biologics. Excluding allergic cross-reactivity or sensitization, we finally tested adalimumab by a graded challenge.

After a suspected allergic reactions to first dose of mRNA COVID-19 vaccine, given the PEG skin tests negativity and tolerance in vivo to PEG containing drugs, five patients were vaccinated with the second dose of Pfizer-Biontech undergoing a fractional protocol, with antihistamine premedication, without presenting immediate or delayed reactions.

The role of Immunotherapy in Chronic Urticaria is unclear, except for isolated circumstances. Hymenoptera sting causes acute urticaria and no report of CU after Hymenoptera sting can be found in the literature. We describe a case of onset of CU after multiple wasp stings that remitted during venom immunotherapy.

Background: There is controversy whether taking β-blockers or ACE inhibitors (ACEI) is a risk factor for more severe systemic insect sting reactions (SSR) and whether it increases the number or severity of adverse events (AE) during venom immunotherapy (VIT). Methods: In this open, prospective, observational, multicenter trial, we recruited patients with a history of a SSR and indication for VIT. The primary objective of this study was to evaluate whether patients taking β-blockers or ACEI show more systemic AE during VIT compared to patients without such treatment. Results: In total, 1,425 patients were enrolled and VIT was performed in 1,342 patients. Of all patients included, 388 (27.2%) took antihypertensive (AHT) drugs (10.4% took β-blockers, 11.9% ACEI, 5.0% β-blockers and ACEI). Only 5.6% of patients under AHT treatment experienced systemic AE during VIT as compared with 7.4% of patients without these drugs (OR: 0.74, 95% CI: 0.43–1.22, p=0.25). The severity of the initial sting reaction was not affected by the intake of β-blockers or ACEI (OR: 1.14, 95% CI: 0.89–1.46, p=0.29). In total, 210 (17.7%) patients were re-stung during VIT and 191 (91.0%) tolerated the sting without systemic symptoms. Of the 19 patients with VIT treatment failure, 4 took β-blockers, none an ACEI. Conclusions: This trial provides robust evidence that taking β-blockers or ACEI does neither increase the frequency of systemic AE during VIT nor aggravate SSR. Moreover, results suggest that these drugs do not impair effectiveness of VIT. (Funded by Medical University of Graz, Austria; Clinicaltrials.gov number, NCT04269629)

Systemic mastocytosis (SM) can be extremely heterogeneous and its treatment should be highly individualized. We reported a description of clinical management of an aggressive SM characterized at diagnosis by multiple organ involvement. The patient underwent to different lines of treatment, from standard chemotherapy to the novel tyrosine kinase inhibitor midostaurin.