Systemic allergic reactions induced by labile plant-food allergens: Seeking potential cofactors. A multicenter study.

BACKGROUND: Heat-and-pepsin-sensitive plant food allergens (PR-10 and profilin) sometimes cause systemic reaction. OBJECTIVE: To detect the risk factors for systemic reactions induced by labile food allergens. METHODS: A retrospective multicenter study was performed on patients with a documented history of systemic allergic reaction to labile plant food allergens and on age-matched controls with a history of oral allergy syndrome (OAS) induced by the same foods. Offending foods, their amount, and state (solid or liquid), and potential cofactors (nonsteroidal anti-inflammatory drugs, protonic pump inhibitors, exercise, alcohol, and fasting) were considered. RESULTS: We studied 89 patients and 81 controls. Sensitization to PR-10 or profilin, IgE to Bet v 1 and/or Bet v 2, and foods causing OAS were similar in the two groups. Twenty patients experienced >1 systemic allergic reaction. Tree nuts, Rosaceae, Apiaceae, and soymilk were the main offending foods. Seventeen (19%) patients were taking a PPI when the systemic reaction occurred (vs 5% in controls; P < .025). The ingestion of the offending food in liquid form (soymilk) was frequent among patients (15%) but unusual among controls (2%; P < .025). Soy milk-induced systemic reactions were independent of PPI treatment. Fasting and excess of allergen, but not NSAID and exercise, were other relevant cofactors for systemic reactions. Systemic reactions occurred without any identifiable cofactor in 39 (44%) cases. CONCLUSION: PR-10- and profilin-induced systemic reactions are facilitated by PPI, ingestion of large amounts of unprocessed foods, and fasting. Soybean beverages represent a risk for PR-10 hypersensitive patients and should be avoided.

Avoidance of nonsteroidal anti-inflammatory drugs after negative provocation tests in urticaria/angioedema reactions: Real-world experience.

Drug provocation tests (DPTs) are the gold standard in diagnosing nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity; however, only few data about follow-up of patients with negative DPTs are actually available. The aim of this study was to assess patients' behavior in taking NSAIDs again and to evaluate NSAID tolerability after negative allergological workup. This is a follow-up study involving patients evaluated for history of cutaneous reactions (urticaria and or angioedema) after NSAID intake and with negative DPTs with the suspected NSAID. Patients were asked during a phone interview about the intake of NSAIDs, tolerance, or reasons of avoidance. The negative predictive value (NPV) of NSAIDs DPTs was calculated. One hundred eleven of 142 patients were successfully contacted; 46/111 (41.44%) took the same NSAID previously tested with two adverse reactions reported (4.34%). Fifty-three of 111 (47.74%) patients did not take the same NSAID, but 34 of them took at least another strong cyclooxygenase (COX) 1 inhibitor, with 1 adverse reaction (2.94%) and 19 of them took only weak COX-1 inhibitors. Twelve of 111 patients (10.8%) did not take any NSAID. Reasons for drug avoidance were mainly fear of reactions (70.8%) and no need (29.2%). NPV, overall, was 96.97% (95% confidence interval, 91-99%). Although NSAID hypersensitivity diagnosis was ruled out by oral provocation test, the majority of patients with a history of urticaria/angioedema avoided the intake of the tested NSAIDs for fear of new reactions, particularly when strong COX-1 inhibitor NSAIDs were involved. The high NPV value of DPT resulting from this study should reassure NSAID intake.

Provocation tests with the offending nonsteroidal anti-inflammatory drugs in patients with urticaria/angioedema reactions.

The provocation test (PT) with the suspected drug represents the gold standard in the diagnosis of non-IgE hypersensitivity reactions to nonsteroidal anti-inflammatory drugs (NSAIDs). Nevertheless, there is no consensus regarding the clinical management of suspected NSAID-sensitive patients. This study assessed if a PT with the suspected drug is a reliable and safe proceeding to confirm NSAID hypersensitivity in patients with a clinical history of urticaria/angioedema (Urt/AE). It also analyzed different patient characteristics (such as gender, age, atopy, dermographism, time interval between the last drug reaction, and number of previous NSAID reactions) in relation to PT positivity. One hundred fifty-nine patients with Urt/AE apparently related to assumption of one or more NSAIDs underwent PT with the suspected drugs. Moreover, to distinguish single/multiple NSAID reactivity in patients who did not tolerate the offending NSAID, another strong cyclooxygenase-1 inhibitor PT was performed. PT was negative in 142/159 patients (89.31%), ruling out a diagnosis of NSAIDs hypersensitivity; 17/159 patients (10.69%) experienced a reaction of Urt/AE during the PT: 8 patients were diagnosed as single reactors to NSAIDs and 4 as multiple reactors to NSAIDs. Those with a history of multiple NSAID reactions and male patients were both more likely to have a positive PT. Our results suggest that in all patients with history of NSAID cutaneous reactions, the NSAID hypersensitivity should be confirmed by an oral PT and that the diagnostic proceeding can safely start with the offending NSAID.

Adherence to Allergen Subcutaneous Immunotherapy is Increased by a Shortened Build-Up Phase: A Retrospective Study.

Introduction. The poor long-term adherence is known to affect the efficacy of allergen immunotherapy (AIT). In the case of injection AIT (SCIT), one of the main determinants is the inconvenience for patients to undergo prolonged build-up phases. Thus, simplifying the time schedule of the induction protocol could be effective in increasing the adherence to SCIT. METHODS: We backtracked the SCIT renewal orders, thanks to the cooperation of the manufacturing company, and we compared the long-term adherence of 152 patients, who were prescribed with an abbreviated build-up schedule (4 injections, allergoid) with that of 302 patients treated with the same product, but with the traditional build-up protocol (7 injections). RESULTS: According to the patient-named refills, those patients on the abbreviated build-up were significantly more compliant at the 2nd and 3rd year of treatment compared to the other group (p=0.0001). The drop-out rate after one year was also significantly lower between the two groups (p=0.0001). The drop-out rate after one year was also significantly lower between the two groups (p=0.0001). The drop-out rate after one year was also significantly lower between the two groups (. CONCLUSIONS: Abbreviating the build-up phase by reducing the number of injections significantly improves patients' adherence to SCIT.

Wheat allergy: a double-blind, placebo-controlled study in adults.

BACKGROUND: Wheat is believed to be an uncommon cause of food allergy in adults; the number of studies that address IgE mediated wheat allergy in adults is all too few. OBJECTIVE: Determine how many subjects with a history of wheat allergy have real allergy by double-blind, placebo-controlled food challenge; identify the symptoms manifested during the challenge; determine the lowest provocation dose; determine the performance characteristics of wheat skin prick test and specific IgE; identify subjects with real wheat allergy for potential immunoblotting studies. METHODS: Patients underwent skin test with commercial wheat extract; specific wheat IgE was determined. Subjects were challenged with 25 g wheat. Subjects who were positive to raw wheat challenge underwent cooked wheat challenge. RESULTS: Thirty-seven double-blind placebo-controlled wheat challenges were performed on 27 patients. A total of 13 of 27 (48%) patients had a positive result. Eleven subjects with positive raw wheat challenge underwent cooked wheat challenge: 10 were positive. The provocation dose range was 0.1 to 25 g. Twenty-seven percent of the subjects allergic to wheat had a provocation dose that was < or =1.6 g. CONCLUSION: Wheat causes real food allergy in adults. More than a quarter of the patients allergic to wheat reacted to less than 1.6 g wheat. Specific IgE was more sensitive than skin test for wheat; however, specificity and predictive values were low for both tests. Thus, these tests should not be used to validate diagnosis of wheat allergy.