The role of skin tests with polyethylene glycol and polysorbate 80 in the vaccination campaign for COVID-19: results from an Italian multicenter survey.

Summary: Background. International guidelines suggested skin tests with Polyethylene-glycol (PEG) and polysorbate 80 (PS-80), to investigate a possible hypersensitivity to these excipients either to identify subjects at risk of developing allergic reactions to Covid-19 vaccines, or in patients with suspected IgE mediated hypersensitivity reactions (HR) to the Covid-19 vaccine. The main purpose of this study was to investigate the prevalence of PEG and PS sensitization in patients with a clinical history of HR to drugs containing PEG/PS and in patients with a suspected Covid-19 vaccine immediate HR. Methods. This was a multicenter retrospective study conducted by allergists belonging to 20 Italian medical centers. Skin testing was performed in 531 patients with either a clinical history of suspected hypersensitivity reaction (HR) to drugs containing PEG and/or PS-80 (group 1:362 patient) or a suspected HR to Covid-19 vaccines (group 2: 169 patient), as suggested by the AAIITO/SIAAIC guidelines for the "management of patients at risk of allergic reactions to Covid-19 vaccines" [1]. Results. 10/362 (0.02%) had positive skin test to one or both excipients in group 1, 12/169 (7.1%) in group 2 (p less than 0.01). In group 2 HRs to Covid-19 vaccines were immediate in 10/12 of cases and anaphylaxis occurred in 4/12 of patients. Conclusions. The positivity of skin test with PEG and or PS before vaccination is extremely rare and mostly replaceable by an accurate clinical history. Sensitization to PEG and PS has to be investigated in patients with a previous immediate HR to a Covid-19 vaccine, in particular in patients with anaphylaxis.

Epinephrine autoinjector prescription in food-allergic adults: symptom-based only or allergen-based also? An Italian multi-centre study.

BACKGROUND: Epinephrine is the treatment of choice for acute food-allergic reactions but existing guidelines state that it should be prescribed uniquely to patients who already experienced at least one food-induced anaphylactic episode. OBJECTIVE: We investigated whether in Italy epinephrine auto-injector is prescribed uniquely following the existing guidelines only, or is allergen-informed as well (i.e., based on the potential risk associated with sensitization to certain food allergens), and hence preventive. METHODS: 1110 adult patients (mean age 31 years; M/F 391/719) with food allergy seen at 19 allergy outpatient clinics were studied. Patients with a history of probable anaphylaxis were identified. Subjects were classified as having primary (type 1) and/or secondary (type 2) food allergy and were divided into several subgroups based on the offending allergen/food. Epinephrine prescriptions were recorded and analyzed both as a whole and by sensitizing allergen. RESULTS: Epinephrine was prescribed to 138/1100 (13%) patients with a significant difference between subjects with type-1 and type-2 food allergy (132/522 [25%] vs. 6/629 [1%]; p < 0.001). The epinephrine group included most patients with a history of anaphylaxis (55/62 [89%]) or emergency department visits 106/138 (77%). In some specific subsets, namely fish-, tree nuts-, and lipid trasfer protein (LTP)-allergic patients, epinephrine was prescribed to patients without a history of systemic allergic reactions. CONCLUSIONS: Italian allergy specialists prescribe epinephrine auto-injectors both on the basis of clinical history of severe reactions and on a critical analysis of the hazard associated with the relevant protein allergens, which suggests a good knowledge of allergens as well as acquaintance with the guidelines for prescription of emergency medication.

EpidemAAITO: features of food allergy in Italian adults attending allergy clinics: a multi-centre study.

BACKGROUND: Studies of the prevalence of different types of food allergy in adults are lacking. OBJECTIVE: To define the prevalence of IgE-mediated food allergies in Italian adults attending allergy clinics and to assess possible differences associated with geographical position and/or dietary habits. METHODS: Seventeen allergy outpatient clinics scattered throughout Italy participated to a multi-centre study in 2007. The number of atopic subjects and of food allergic patients along with clinical features were recorded by pre-defined criteria. Patients with unequivocal history of food allergy confirmed by positive skin prick test were included as cases. RESULTS: Twenty five thousand six hundred and one subjects were screened; 12,739 (50%) were atopic, and 1079 (8,5%) had IgE-mediated food allergy. Sixty four percent of patients were females. Overall, the most frequent food allergy was the pollen-food allergy syndrome (55%), which was associated with oral allergy syndrome in 95% of cases and whose frequency decreased southbound. Forty-five percent of patients had a type 1 food allergy, in most cases (72%) caused by fruits and vegetables, and generally associated with a history of systemic symptoms. Type 1 food allergies represented 96% of food allergies in the South. Lipid transfer protein (LTP) accounted for 60% of sensitizations and caused most primary food allergies in all areas. CONCLUSION: Plant-derived foods cause most food allergies in Italian adults. The pollen-food allergy syndrome is the most frequent type of food allergy followed by allergy to LTP whose frequency increases southbound. The pattern of allergy to certain foods is clearly influenced by specific geographic features such as pollen exposure and dietary habits.

Causes of food-induced anaphylaxis in Italian adults: a multi-centre study.

BACKGROUND: Data about food-induced anaphylaxis in Italy are missing. OBJECTIVE: It was the aim of this study to detect the main foods/food allergens causing anaphylaxis in Italy. METHODS: The frequency of anaphylaxis and the relative importance of many offending foods were assessed in 1,110 adult patients with food allergy diagnosed by common criteria at 19 allergy centres scattered throughout Italy from 1 January to 31 December 2007. RESULTS: Fifty-eight of 1,110 (5%) food-allergic patients experienced at least 1 episode of anaphylaxis. On average, they were older than other food-allergic patients (34 vs. 31 years; p < 0.05). The majority of anaphylactic episodes occurred in patients sensitized to lipid transfer protein (LTP; n = 19), followed by shrimp (n = 10), tree nuts (n = 9), legumes other than peanut (n = 4), and seeds (n = 2); peanut, spinach, celery, buckwheat, wheat, avocado, tomato, fish, meat, and Anisakis caused an anaphylactic reaction in single patients. Among LTP-hypersensitive patients, peach caused 13/19 anaphylactic episodes. Shrimp-allergic patients were significantly older than other patients with food-induced anaphylaxis (p < 0.05), whereas patients allergic to LTP experienced their anaphylactic episodes at a younger age (p < 0.001). The frequency of anaphylaxis among patients sensitized to LTP, shrimp or tree nuts did not differ between northern and central/southern Italy. CONCLUSION: LTP is the most important allergen causing food-induced anaphylaxis in Italy, peach being the most frequently offending food. Peanut-induced anaphylaxis seems very uncommon. Geographic and environmental differences both between Italy and other countries and within Italy seem to play a relevant role in the pattern of sensitization to foods.

Breath analysis in patients with end-stage renal disease: effect of haemodialysis.

BACKGROUND: There is no agreement about exhaled nitric oxide (FE(NO)) and its change after haemodialysis (HD) in end-stage renal disease (ESRD) patients. To comprehensively assess NO production in the respiratory system, NO metabolites in exhaled breath condensate (EBC) needs to be measured in addition to FE(NO), taking into account the influence on these markers of airway pH, which may be regulated by ammonia (NH3+), present in large amounts in the breath of ESRD patients and removed by HD. STUDY DESIGN: FE(NO) and NO metabolites (NOx, NO2-,NO3- ), pH and NH3+ in EBC were measured in 12 ESRD patients, before and after HD. Twelve healthy subjects acted as controls. RESULTS: FE(NO )values of ESRD patients were similar to normals, while EBC-NOx, NO2-, NH3+ and pH were significantly higher in ESRD patients compared to normals (EBC-NOx 12.3, range 11.1-41.9 microm vs. 9.4, range 4.6-10.9 microm, P = 0.007; NO2- 4.70, range 1.17-8.22 microm vs. 0.90, range 0.72-1.17 microm, P = 0.023; NH3+ 2340, range 1325-3922 microm vs. 660, range 406-872 microm, P < 0.001; pH 7.16, range 6.82-7.44 vs. 6.60, range 6.42-6.76, P = 0.004, respectively). HD caused a mild significant decrease of FE(NO), and normalization of NH3+, NOx, NO2- and pH. A significant positive relationship between EBC-pH and EBC-NH3+ before and after HD (r(2) = 0.65, P = 0.000) was observed, explaining higher than normal EBC-pH before HD, while no relationship was found between EBC-pH and FE(NO) or NO metabolites. CONCLUSION: Oxidative stress, and not EBC-pH, is the most probable cause of increased NO metabolites in ESRD patients before HD.