How to Take a Good Clinical History in Cases of Allergic Reactions to Medications.

The clinical history is the cornerstone of the doctor´s work. When assessing patients consulting for a suspected hypersensitivity reaction to a drug, the details collected in the patient´s clinical history are essential when deciding which tests to perform and for making recommendations about which drugs the patient should avoid and which can be taken. This area is especially important today, since many patients are labeled as allergic to drugs, especially penicillins, without this being the case. This article reviews the importance of the clinical history in a patient with a hypersensitivity reaction to a drug and considers which data should be collected. Likewise, a record-based model is proposed to help standardize the clinical history.

Unraveling the Diagnosis of Kiwifruit Allergy: Usefulness of Current Diagnostic Tests.

OBJECTIVES: To determine the usefulness of the in vitro and in vivo methods used in the diagnosis of kiwifruit allergy and to specifically assess the impact of seed proteins on sensitivity. METHODS: We performed skin prick tests (SPTs) using various commercial extracts, homemade pulp, and seed extracts and prick-prick tests with kiwifruit on 36 allergic patients. The presence of specific IgE (sIgE) was assessed using the ImmunoCAP (kiwifruit extract), ELISA (Act d 1, Act d 2), ISAC, and FABER assays. Immunoblotting of seed extract was carried out, and a single-blind oral food challenge was performed with whole seeds in seed-sensitized individuals. RESULTS: The prick prick test with kiwifruit demonstrated the highest diagnostic capacity (81.8% sensitivity and 94.1% specificity) among the in vivo tests. The sIgE levels measured using ImmunoCAP (kiwifruit extract) showed a similar sensitivity to that of global ISAC and FABER (63.9%, 59.5%, and 58.3%, respectively). Act d 1 was the major allergen. Sensitization to Act d 1 was associated with positive sIgE results to whole kiwifruit extract detected by ImmunoCAP (P<.000). A positive SPT result to kiwifruit seeds was associated with severe symptoms induced by kiwifruit (P=.019) as a marker of advanced disease, but not with clinically relevant sensitization. Challenge testing with kiwifruit seeds performed on 8 seed-sensitized patients yielded negative results. CONCLUSION: Sensitization to Act d 1 is associated with a positive result in conventional diagnostic techniques, whereas kiwifruit seed sensitization does not increase the sensitivity of the diagnostic techniques evaluated.

Practical Guidelines for Perioperative Hypersensitivity Reactions.

Perioperative hypersensitivity reactions constitute a first-line problem for anesthesiologists and allergists. Therefore, hospitals should have a consensus protocol for the diagnosis and management of these reactions. However, this kind of protocol is not present in many hospitals, leading to problems with treatment, reporting of incidents, and subsequent etiological diagnosis. In this document, we present a systematic review of the available scientific evidence and provide general guidelines for the management of acute episodes and for referral of patients with perioperative hypersensitivity reactions to allergy units. Members of the Drug Allergy Committee of the Spanish Society of Allergy and Clinical Immunology (SEAIC) have created this document in collaboration with members of the Spanish Anesthesia Society (SEDAR). A practical algorithm is proposed for the etiologic diagnosis, and recommendations are provided for the management of hypersensitive patients.

Biological characterization and mating compatibility of Helicoverpa gelotopoeon (D.) (Lepidoptera: Noctuidae) populations from different regions in Argentina.

Helicoverpa gelotopoeon, the South American bollworm, is a polyphagous pest of the Heliothinae complex that causes damage to soybean, cotton, and chickpea crops. Some species within this complex have developed resistance to genetically modified crops and insecticides, which has led to increased interest in their genetic diversity and population structure. The objective of this study was to characterize biological and reproductive parameters of two populations of H. gelotopoeon collected in two different provinces of Argentina. Intra- and inter-population crosses revealed that H. gelotopoeon populations from both regions of Argentina did not present evidence of pre-zygotic and post-zygotic incompatibility, suggesting that Tucumán and Córdoba populations of H. gelotopoeon belong to a single wide-ranging species. Our data support the occurrence of substantial gene flow between H. gelotopoeon populations, probably due to the widely documented, long-range migratory capacity of Heliothinae species.

Comparable actions of omalizumab on mast cells and basophils.

BACKGROUND: Omalizumab (OmAb) has recently been approved for the treatment of diseases other than allergic asthma, including chronic urticaria. The exploration of the use of OmAb in chronic urticaria was based on the presence of IgE autoantibodies against autoantigens such as anti-IgE, anti-FcεRI, and IgE antibodies against thyroid peroxidase in certain patients with chronic urticaria. OmAb recognizes and sequesters free IgE to prevent its interaction with FcεRI. However, OmAb is equally and rapidly effective against autoimmune and non-autoimmune urticaria, suggesting the possible involvement of additional mechanisms of IgE. OBJECTIVES: We sought to investigate the in vitro mechanism of action of OmAb in mast cells and basophils. METHODS: Both LAD2 human mast cell line, previously sensitized with IgE, and ex vivo basophils were incubated with OmAb at different doses, analysing its effect on IgE-dependent events (e.g., degranulation, phosphorylation-mediated signalling, and eicosanoid release). RESULTS: We found that OmAb dissociates pre-bound IgE from mast cells and basophils, resulting in a reduction of proximal phosphorylation-mediated signalling events (Syk, PLCγ, and LAT) and in a decrease in degranulation and leukotriene synthesis. CONCLUSION: Our data prove the existence of common mechanisms of action of OmAb in mast cells and basophils that would explain its effectiveness and rapid effect in chronic urticaria and provide a basis for its use in other diseases mediated by these cells.

Prick test: evolution towards automated reading.

The prick test is one of the most common medical methods for diagnosing allergies, and it has been carried out in a similar and laborious manner over many decades. In an attempt to standardize the reading of the test, many researchers have tried to automate the process of measuring the allergic reactions found by developing systems and algorithms based on multiple technologies. This work reviews the techniques for automatic wheal measurement with the aim of pointing out their advantages and disadvantages and the progress in the field. Furthermore, it provides a classification scheme for the different technologies applied. The works discussed herein provide evidence that significant challenges still exist for the development of an automatic wheal measurement system that not only helps allergists in their medical practice but also allows for the standardization of the reading and data exchange. As such, the aim of the work was to serve as guideline for the development of a proper and feasible system.

Reproductive isolation between two populations of Diatraea saccharalis (F.) (Lepidoptera: Crambidae) from different host plant species and regions in Argentina.

The sugarcane borer, Diatraea saccharalis (F.), has a widespread distribution throughout the Western Hemisphere and is a pest of many crop plants including sugarcane, corn, sorghum and rice. The use of Bacillus thuringiensis (Bt) corn has been the primary tool for managing this species in corn fields. Sugarcane borer control has been recently threatened by observations of susceptibility and/or resistance to certain varieties of Bt corn and the protein used in many newer varieties. This has led to increased interest in understanding sugarcane borer genetic diversity and gene flow within and among its populations and the consequent exchange of alleles between geographically distant populations. The objective of this study was to examine reproductive compatibility between host-associated geographic populations of D. saccharalis in Argentina and to determine whether this pest represents a complex of host-associated cryptic species rather than a wide ranging generalist species. Intra and inter-population crosses revealed that D. saccharalis populations from the northwestern and Pampas regions presented evidence of prezygotic and postzygotic incompatibility. Such a result is likely to be the product of an interruption of gene flow produced by either geographic or host plant associated isolation, suggesting that Tucumán (northwestern) and Buenos Aires (Pampas) populations of D. saccharalis are a distinct genotype and possibly an incipient species.

Do Skin Prick Test and In Vitro Techniques Diagnose Sensitization to Peach Lipid Transfer Protein and Profilin Equally Well in Allergy to Plant Food and Pollen?

OBJECTIVE: To compare the skin prick test (SPT) with in vitro techniques (single and multiplex fluorescence enzyme-immunoassay [FEIA]) for detecting sensitization to profilin and lipid transfer protein (LTP). METHODS: We retrospectively studied 181 patients with pollen and/or plant food allergy and 61 controls. SPT was performed with date palm profilin (Pho d 2) and peach LTP (Pru p 3), and specific IgE (sIgE) to Phl p 12 and Pru p 3 was analyzed using single FEIA and microarray. RESULTS: Fifteen of 201 patients with negative results for LTP in the SPT were sensitized to this allergen in the in vitro tests, and 18 of 41 patients with positive results for LTP in the SPT were not sensitized according to the in vitro tests. Seventeen of 186 patients with negative results for profilin in the SPT were sensitized to Phl p 12 by serum sIgE, and 30 out of 56 patients with positive results for profilin in SPT were not sensitized to Phl p 12 according to the other tests. Moderate agreement was observed between the 3 techniques studied. CONCLUSIONS: SPT is a sensitive technique for detecting sensitization to LTP and profilin. Its results are similar to those of in vitro techniques, especially in patients with negative SPT results for peach LTP and palm tree profilin.

The usefulness of plasma histamine and different tryptase cut-off points in the diagnosis of peranaesthetic hypersensitivity reactions.

UNLABELLED: Anaesthetic hypersensitivity reactions can be IgE- or not IgE-mediated and are a challenge to find the causal agent. Histamine and tryptase determination are classically considered useful in the diagnosis of these reactions. The aim of our study was to assess the diagnostic usefulness of plasma histamine and different cut-off points of serum tryptase. METHODS: Patients suffering a reaction suggestive of hypersensitivity during general anaesthesia in Clínica Universidad de Navarra (2008-2012) were included. Serum tryptase and plasma histamine were measured at the time of the reaction and 2 h later. Baseline tryptase was also determined. Four to eight weeks after the reaction an allergological study was performed to all the drugs or products involved in the reaction. RESULTS: Sixty-five patients suffered an immediate hypersensitivity reaction during the period of the study. Thirty-seven patients (20 male) with median age 48 years (12-79) were included because they completed allergological study, and histamine and tryptase were correctly obtained. Elevated plasma histamine was observed in 34 cases (92%). Tryptase exceeded twice the basal values in 10 patients (31%). Using different cut-off points of tryptase, the number of patients with elevated tryptase would be 15 patients (41%) for a cut-off point of 5 µg/L; 12 patients (32%) for a cut-off point of 8.23 µg/L; nine patients (24%) for 10.5 µg/L; and eight patients (22%) for 11.4 µg/L. The median tryptase level for the IgE-mediated reactions was 9.0 µg/L (2-70 µg/L) and 4.0 µg/L (3-13 µg/L) in non-IgE-mediated reactions (P < 0.01). Median tryptase levels were higher in more severe reactions (grade 2 or 3) in comparison with grade 1. The best ratio for serum-tryptase-during-reaction/basal-serum-tryptase to discriminate between IgE and non-IgE reactions was 2.0. CONCLUSION: The best criterion for discriminating IgE- and non IgE-mediated hypersensitivity reactions in anaesthesia was a tryptase value exceeding twice the basal one.

Staphylococcus aureus genomic pattern and atopic dermatitis: may factors other than superantigens be involved?

The purpose of this investigation was to compare the genotypic profiles of Staphylococcus aureus isolated from atopic dermatitis (AD) patients and from control subjects, and to study the relationship between clinical severity, immune response, and genomic pattern of S. aureus isolated from AD patients. We selected 32 patients with AD and S. aureus skin colonization and 31 atopic controls with no history of AD who where asymptomatic carriers of S. aureus. Microarray-based genotyping was performed on S. aureus isolates. In AD patients, clinical severity was assessed using the Scoring Atopic Dermatitis index and total IgE levels and staphylococcal superantigen-specific IgE levels (SEA, SEB, SEC, TSST1) were determined. The genes lukE, lukD, splA, splB, ssl8, and sasG were more frequent in isolates from AD patients. CC30 was more common in isolates from atopic controls than in AD patients. There was a correlation between total IgE and clinical severity, but an association between clinical severity, immune response, and the presence of S. aureus superantigen genes, including enterotoxin genes, could not be demonstrated. Finally, a correlation was found between AD severity and other S. aureus genes, such as sasG and scn. S. aureus factors besides superantigens could be related to the worsening and onset of AD.

Hypersensitivity reactions to biological drugs.

Strictly speaking, biological drugs are defined as drugs obtained using biotechnology that act on the immune system. They encompass monoclonal antibodies, fusion proteins, and cytokines. Although they are restricted to specific diseases, they have been increasingly used in recent years, with the consequent reporting of adverse reactions, many of which occur during the postmarketing phase. Because of the characteristics of adverse reactions, a new classification has been proposed. Hypersensitivity reactions are beta-type reactions and include infusion reactions and injection site reactions. In some cases, an immune mechanism mediated by IgE, IgG, or T cells is involved. Clinical symptoms vary widely, from skin reactions to anaphylaxis. Diagnostic studies are based on skin tests and in vitro tests (specific IgE, basophil activation test). Most are not standardized and are conducted in small groups of patients, thus making it impossible to obtain sensitivity and specificity values. With some biological drugs, desensitization protocols have proven successful. In this review, we discuss hypersensitivity reactions to biological drugs and the diagnostic tests used to assess these reactions.

Early skin testing is effective for diagnosis of hypersensitivity reactions occurring during anesthesia.

Allergic skin tests have to be performed 4-6 weeks after an allergic anesthetic reaction. Patients with allergic reactions during anesthesia were prospectively included (n = 44). Skin tests were performed in two stages: (i) Stage 1 (S1), 0-4 days after the reaction; and (ii) Stage 2 (S2), 4-8 weeks after. Five (11.5%) surgical procedures were suspended due to the reaction. Positive skin tests were obtained in 25/44 patients (57%). Allergic diagnosis was carried out at S1 in 15/25 (60%) and at S2 in 10/25 (40%). Three patients resulted positive only in S1. Overall agreement among S1 and S2 skin tests was 70.45%. The kappa statistic was 0.41 (P-value = 0.002). Odds ratio of obtaining a false negative in S1 (compared with S2) was 3.33. Early allergological study is useful, could minimize false negatives, but should be considered as a complement to late skin tests.