Sesame allergy in children: New insights into diagnosis and management.

Sesame is a potentially potent allergen that can trigger skin, gastrointestinal, and respiratory tract symptoms, and anaphylaxis. Only 20% to 30% of sesame-allergic children develop tolerance. The prevalence of sesame allergy depends on local diets and ranges from 0.1% to 0.9%. A high risk of accidental exposure to sesame has resulted in mandatory food labeling in many countries. More than half of patients with sesame allergy are also allergic to peanut/tree nuts. Serum-specific IgE testing with a quantitative Ses i 1 component can be performed safely and has higher clinical specificity and better positive predictive value for oral food challenge (OFC) than whole sesame extract or skin prick testing (SPT). Compared with SPT or OFC, in vitro Ses i 1 testing requires no special techniques and carries no risk of reactions. Diagnosis of suspected sesame allergy begins with a thorough history and physical examination. A positive sesame extract test (≥0.1 kUA /L) should prompt further testing. In patients with a high probability of reacting, results of component testing may facilitate a decision about performing an OFC. In a Japanese study of OFC and Ses i 1, there was a 5% probability of a positive OFC with Ses i 1 sIgE levels <0.13 kUA /L, and a 50% probability of a positive OFC with levels >32.0 kUA /L. Most patients could safely consume sesame if sIgE levels were <0.13 kUA /L. Ses i 1 testing can be used to guide appropriate management (avoidance, emergency medication, and oral immunotherapy).

Pilot study to determine the concordance between skin prick and intradermal test (IDT) reactivity to environmental allergens in atopic dogs using IDT as the gold standard.

BACKGROUND: Prick testing is widely used as the first-line in vivo test for environmental allergens in people owing to its noninvasive nature and speed of performance. OBJECTIVES: To determine concordance between skin prick testing (SPT) and intradermal testing (IDT) reactivity to environmental allergen mixes in dogs with atopic dermatitis (cAD). ANIMALS: Forty client-owned dogs with cAD. MATERIALS AND METHODS: Skin prick testing (GREER Pick System; Stallergenes Greer) and IDT were performed on 40 dogs using seven glycerinated and aqueous environmental allergen mixes, respectively (tree, grass and weed pollens, house dust mites and three mould mixes). Reactions for IDT and SPT were evaluated both subjectively and objectively (mean wheal diameter; MWD) and compared to saline and histamine controls. RESULTS: Using IDT as the gold standard, with subjective scoring, SPT was 47.0% sensitive [95% confidence interval (CI) 36.0%-58.7%], 92.1% specific (95% CI 87.6%-95.3%) and agreement was moderate (79%, Cohen's kappa = 0.424). The positive predictive value of SPT was 36% and negative predictive value was 95%. Objective and subjective scores had only fair agreement. CONCLUSIONS AND CLINICAL RELEVANCE: Skin prick testing with allergen mixes was specific yet poorly sensitive as compared to IDT. For both IDT and SPT, 95% (38 of 40) dogs failed to react to an allergen mix, despite showing a positive reaction to at least one component. Future studies comparing SPT and IDT should test individual allergens rather than mixes to prevent the dilution of individual components, which may have resulted in false negatives.

The first reptilian allergen and major allergen for fish-allergic patients: Crocodile ß-parvalbumin.

BACKGROUND: Clinical cross-reactivity between bony fish, cartilaginous fish, frog, and chicken muscle has previously been demonstrated in fish-allergic patients. In indicative studies, two reports of anaphylaxis following the consumption of crocodile meat and IgE-cross-binding were linked to the major fish allergen parvalbumin (PV). This study investigates IgE-binding proteins in crocodile meat with a focus on PV and their clinical relevance. METHODS: Proteins were extracted from muscle tissue of crocodile, three bony fish, and two cartilaginous fish. A cohort of fish-allergic pediatric patients (n = 77) underwent allergen skin prick testing (SPT) to three fish preparations (n = 77) and crocodile (n = 12). IgE-binding proteins were identified and quantified by SDS-PAGE, mass spectrometric analyses, and immunoblotting using commercial and in-house antibodies, as well as individual and pooled patients' serum. PV isoforms were purified or recombinantly expressed before immunological analyses, including human mast cell degranulation assay. RESULTS: Of the tissues analyzed, PV was most abundant in heated crocodile preparation, triggering an SPT of ≥3 mm in 8 of 12 (67%) fish-allergic patients. Seventy percent (31 of 44) of fish PV-sensitized patients demonstrated IgE-binding to crocodile PV. Crocodile ß-PV was the major IgE-binding protein but 20-fold less abundant than α-PV. Cellular reactivity was demonstrated for ß-PV and epitopes predicted, explaining frequent IgE-cross-binding of ß-PVs. Both PV isoforms are now registered as the first reptile allergens with the WHO/IUIS (ß-PV as Cro p 1 and α-PV as Cro p 2). CONCLUSION: Fish-allergic individuals may be at risk of an allergy to crocodile and should seek specialist advice before consuming crocodilian meat.

Occupational contact urticaria to cannabis sativa.

Cannabis allergy is not commonly reported, perhaps due to the legal status of cannabis use and the difficulties of obtaining permission to test it. We report 3 cases of work-related cannabis allergy with features suggestive of a dermatitis, rather than a contact urticaria. Only prick tests were able to confirm the diagnosis. Identification of the cause of the rash was essential to direct work re-deployment.

The impact of skin prick testing on pain perception and anxiety in children and parents.

BACKGROUND: Skin prick testing (SPT) is a major diagnostic tool in patients with allergic symptoms. The testing process may involve pain, anxiety, and stress on children and parents. OBJECTIVE: We aimed to measure the level of pain and anxiety before and after SPT in children and parents, and tried to identify predictive factors. METHODS: The children underwent SPT and parents completed the State Trait Anxiety Inventory (STAI) S-Anxiety before and after SPT, T-Anxiety before SPT. The study nurse completed Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores (<5 years) or Wong-Baker FACES Pain Rating Scale (VAS), (≥5 years) after the SPT, in order to quantify pain. RESULTS: A total of 523 children (5.3 [2.8-9.1] [median, interquartile range] years old, 59.5% male) were evaluated. Parent gender was a predominant factor for anxiety, as mothers had a higher pre-test STAI (S-Anxiety) score, STAI (T-Anxiety), and post-test STAI (S-Anxiety) score than fathers (p < 0.001). Pre-test STAI (S-Anxiety) scores of parents decreased with increasing age (for 0-<5 years, 5-<12 years, and ≥12 years; [p for trend = 0.016]). The children tested on the back had higher VAS scores compared with the ones tested on the forearm [2[0-4] vs 2[0-2], [p = 0.005]). Risk factors determining higher general anxiety STAI (T-Anxiety) scores above the median were female sex for the parent (OR = 1.68; 95% CI [1.10-2.57]; p = 0.017), and parent's education level being greater than or equal to high school level (OR = 1.83; 95% CI [1.27-2.64]; p = 0.001). CONCLUSION: SPT may cause anxiety and pain in a subgroup of children particularly in younger age, and if performed on the back. Anxiety levels were higher in mothers, and in parents with high education levels.

Peanut allergy diagnosis: A 2020 practice parameter update, systematic review, and GRADE analysis.

Given the burden of disease and the consequences of a diagnosis of peanut allergy, it is important that peanut allergy be accurately diagnosed so that an appropriate treatment plan can be developed. However, a test that indicates there is peanut sensitization present (eg, a "positive" test) is not always associated with clinical reactivity. This practice parameter addresses the diagnosis of IgE-mediated peanut allergy, both in children and adults, as pertaining to 3 fundamental questions, and based on the systematic reviews and meta-analyses, makes recommendations for the clinician who is evaluating a patient for peanut allergy. These questions relate to when diagnostic tests should be completed, which diagnostic tests to utilize, and the utility (or lack thereof) of diagnostic testing to predict the severity of a future allergic reaction to peanut.

Peanut allergy diagnosis: Moving from basic to more elegant testing.

Peanut allergy (PNA) is an IgE-mediated immune disorder, which merits particular attention due to its impact on the health and quality of life of millions of patients worldwide. PNA tends to develop in early life and resolves in only 20% of peanut-allergic children. It accounts for the majority of severe food-related allergic reactions. An accurate diagnosis of PNA is vital. In this review, we present the approach to the diagnosis of peanut allergy, starting from the history and proceeding to measures of overall sensitization and then to component-resolved diagnostics and oral food challenges as indicated. Additional testing in development includes basophil activation testing and determination of epitopes for peanut-allergic responses. Based on the literature, stepwise approaches and predictive models for diagnosing PNA are also presented.

Sensitization to Aeroallergens in Patients with Primary Immunodeficiencies.

BACKGROUND: Primary immunodeficiencies (PID) are a heterogeneous group of diseases that cause alterations in the immune system, leading to the increased susceptibility to infections, autoimmune diseases, and malignancies. The aim was to evaluate the presence of clinical manifestations and diagnoses of asthma, rhinitis, and atopic dermatitis in patients diagnosed with PID, and correlate these with allergen sensitization verified by skin prick testing (SPT). MATERIAL AND METHODS: This cross-sectional, descriptive, and observational study was conducted from February 2015 to February 2016. We performed a medical report analysis and SPT for aeroallergens in patients with a PID diagnosis. RESULTS: Thirty-one patients with a PID diagnosis were included. The mean age of the participants was 15.41 years. From the 31 patients, 28 had symptoms suggestive of allergic disease (asthma, rhinitis, and atopic dermatitis) and only 7 presented positive SPT for at least 1 aeroallergen. CONCLUSION: The frequency of allergenic sensitization in the group of patients with PID and symptoms suggestive of asthma, rhinitis, or atopic dermatitis is lower than that found in the general population, probably due the impairment of IgE formation secondary to their immunologic alterations.

Boiling and Pressure Cooking Impact on IgE Reactivity of Soybean Allergens.

BACKGROUND: Soybean is one of the 8 foods that causes the most significant rate of food allergies in the USA and Europe. Thermal processing may impact on the allergenic potential of certain foods. We aimed to investigate modifications of the IgE-binding properties of soybean proteins due to processing methods that have been previously found to impact on the allergenicity of legumes such as peanut. METHODS: Soybean seeds were subjected to different thermal processing treatments. To evaluate their impact on the IgE-binding capacity of soybean proteins, individual sera from 25 patients sensitized to soybean were used in in vitro immunoassays. Detection of specific soybean allergens in untreated and treated samples was carried out with specific monoclonal and polyclonal antibodies. In vivo studies of skin prick testing (SPT) were also performed. RESULTS: The IgE reactivity of soybean was resistant to boiling up to 30 min, and this treatment had a higher impact when applied for 60 min. Treatment that combined heat and pressure produced a fragmentation of proteins in both soluble and insoluble fractions that went along with a decreased capacity to bind IgE and reduced the SPT wheal size. However, allergens such as 7S globulins survived this treatment. CONCLUSIONS: Thermal-processing methods able to attenuate the capacity of soybean proteins to bind IgE may contribute to the improvement of food safety and could constitute a potential strategy for the induction of tolerance to soybean.

Do we still need oral food challenges for the diagnosis of food allergy?

Food challenges are standard in the diagnosis in patients suspected of being allergic to food. However, their role is regularly questioned due to the time required to perform them, and to their cost and the inherent risk of severe reactions. Food challenges have been challenged by recent advances defining threshold values for food-specific IgE helping to predict the probability of having symptoms to the suspected food. Also, identification of major allergens to various highly allergenic foods such as peanuts or tree nuts has contributed to an increased accuracy of IgE testing. Altogether, these new data have contributed to a better definition of the role of oral food challenges in the diagnosis of food allergy. Oral food challenges are not outdated and remain the gold standard in the diagnosis of food allergy.

Opisthorchis felineus negatively associates with skin test reactivity in Russia-EuroPrevall-International Cooperation study.

BACKGROUND: Most studies on the relationship between helminth infections and atopic disorders have been conducted in (sub)tropical developing countries where exposure to multiple parasites and lifestyle can confound the relationship. We aimed to study the relationship between infection with the fish-borne helminth Opishorchis felineus and specific IgE, skin prick testing, and atopic symptoms in Western Siberia, with lifestyle and hygiene standards of a developed country. METHODS: Schoolchildren aged 7-11 years were sampled from one urban and two rural regions. Skin prick tests (SPT) and specific IgE (sIgE) against food and aeroallergens were measured, and data on allergic symptoms and on demographic and socioeconomic factors were collected by questionnaire. Diagnosis of opisthorchiasis was based on PCR performed on stool samples. RESULTS: Of the 732 children included, 34.9% had opisthorchiasis. The sensitization to any allergen when estimated by positive SPT was 12.8%, while much higher, 24.0%, when measured by sIgE. Atopic symptoms in the past year (flexural eczema and/or rhinoconjunctivitis) were reported in 12.4% of the children. SPT was positively related to flexural eczema and rhinoconjunctivitis, but not to wheezing. Opisthorchiasis showed association with lower SPT response, as well as borderline association with low IgE reactivity to any allergen. However, the effect of opisthorchiasis on SPT response was not mediated by IgE, suggesting that opisthorchiasis influences SPT response through another mechanism. Opisthorchiasis also showed borderline association with lower atopic symptoms. CONCLUSIONS: There is a negative association between a chronic helminth infection and skin prick test reactivity even in a developed country.

Greater Real-Life Diagnostic Efficacy of Allergen Molecule-Based Diagnosis for Prescription of Immunotherapy in an Area with Multiple Pollen Exposure.

BACKGROUND: Allergen molecule-based diagnosis has been suggested to facilitate the identification of disease-causing allergen sources and the prescription of allergen-specific immunotherapy (AIT). The aim of the current study was to compare allergen molecule-based IgE serology with allergen extract-based skin testing for the identification of the disease-causing allergen sources. The study was conducted in an area where patients are exposed to pollen from multiple sources (trees, grasses, and weeds) at the same time to compare the diagnostic efficiency of the 2 forms of diagnosis. METHODS: Patients from Astana, Kazakhstan, who suffered from pollen-induced allergy (n = 95) were subjected to skin prick testing (SPT) with a local panel of tree pollen, grass pollen, and weed pollen allergen extracts and IgE antibodies specific for marker allergen molecules (nArt v 1, nArt v 3, rAmb a 1, rPhl p 1, rPhl p 5, rBet v 1) were measured by ImmunoCAP. Direct and indirect costs for diagnosis based on SPT and marker allergen-based IgE serology as well as direct costs for immunotherapy depending on SPT and serological test results were calculated. RESULTS: The costs for SPT-based diagnosis per patient were lower than the costs for allergen molecule-based IgE serology. However, allergen molecule-based serology was more precise in detecting the disease-causing allergen sources. A lower number of immunotherapy treatments (n = 119) was needed according to molecular diagnosis as compared to extract-based diagnosis (n = 275), which considerably reduced the total costs for diagnosis and for a 3-year treatment from EUR 1,112.30 to 521.77 per patient. CONCLUSIONS: The results from this real-life study show that SPT is less expensive than allergen molecule-based diagnostic testing, but molecular diagnosis allowed more precise prescription of immunotherapy which substantially reduced treatment costs and combined costs for diagnosis and treatment.

Pragmatic randomized controlled trial of an allergy intervention for children aged 6-16 with asthma and rhinitis in general practice.

BACKGROUND: It is widely believed that for allergic rhinitis and asthma, avoidance of specific triggers can improve symptom control. Whilst many children with asthma or rhinitis are sensitized to airborne allergens, primary care diagnostic and management decisions are often made without a detailed history of the allergic triggers or allergy testing. Thus, treatment decisions are empirical and allergen avoidance advice is either not given or, if given, not tailored to the child's sensitivities. OBJECTIVE: To ascertain whether allergy assessment and tailored advice in general practice enhances outcomes of children with asthma and rhinitis. METHOD: Pragmatic RCT of allergy intervention (structured allergy history, skin prick testing and appropriate allergy avoidance advice) vs. usual care in children with asthma and/or rhinoconjunctivitis. A blinded observer assessed outcomes at 12 months. Main outcome measures were symptom scores and disease-specific health-related QoL. Secondary outcomes were healthcare utilization, days unable to pursue usual activities and self-rated improvement. RESULTS: A total of 335 participants were randomized to formal allergy assessment or normal care. There were no differences in participants' demographic or clinical characteristics at baseline (all P > 0.05). At 12 months, participants receiving the allergy intervention had fewer rhinitis symptoms (MD - 3.14, 95% CI - 6.01, - 0.81) and an improvement in QoL (MD - 0.50, 95% CI 0.32, 0.68). There were no significant changes in asthma symptoms, healthcare utilization or number of days unable to pursue usual activities. CONCLUSION: Amongst children with known asthma and/or rhinitis in primary care, taking a structured allergy history with skin prick testing and tailored advice on allergy avoidance resulted in reduced symptoms of rhinitis and improved QoL.

A new framework for the interpretation of IgE sensitization tests.

IgE sensitization tests, such as skin prick testing and serum-specific IgE, have been used to diagnose IgE-mediated clinical allergy for many years. Their prime drawback is that they detect sensitization which is only loosely related to clinical allergy. Many patients therefore require provocation tests to make a definitive diagnosis; these are often expensive and potentially associated with severe reactions. The likelihood of clinical allergy can be semi-quantified from an IgE sensitization test results. This relationship varies though according to the patients' age, ethnicity, nature of the putative allergic reaction and coexisting clinical diseases such as eczema. The likelihood of clinical allergy can be more precisely estimated from an IgE sensitization test result, by taking into account the patient's presenting features (pretest probability). The presence of each of these patient-specific factors may mean that a patient is more or less likely to have clinical allergy with a given test result (post-test probability). We present two approaches to include pretest probabilities in the interpretation of results. These approaches are currently limited by a lack of data to allow us to derive pretest probabilities for diverse setting, regions and allergens. Also, cofactors, such as exercise, may be necessary for exposure to an allergen to result in an allergic reaction in specific IgE-positive patients. The diagnosis of IgE-mediated allergy is now being aided by the introduction of allergen component testing which may identify clinically relevant sensitization. Other approaches are in development with basophil activation testing being closest to clinical application.

Pearls and Pitfalls in Diagnosing IgE-Mediated Food Allergy.

The term "food allergy" is used by many patients and clinicians to describe a range of symptoms that occur after ingestion of specific foods. However, not all symptoms occurring after food exposure are due to an allergic, or immunologic, response. It is important to properly evaluate and diagnose immunoglobulin E (IgE)-mediated food allergy as this results in reproducible, immediate onset, allergic reactions that can progress toward life-threatening anaphylaxis. Proper diagnosis requires understanding of the common foods that cause these reactions in addition to key historical elements such as symptoms, timing and duration of reaction, and risk factors that may predispose to development of IgE-mediated food allergy. Diagnostic testing for food-specific IgE can greatly aid the diagnosis. However, false-positive test results are very common and can lead to overinterpretation, misdiagnosis, and unnecessary dietary elimination. This review discusses important aspects to consider during evaluation of a patient for suspected IgE-mediated food allergy.

The Prevalence and Natural History of Food Allergy.

Numerous studies have demonstrated that the prevalence of food allergy is increasing. Not only are more children being diagnosed with food allergies, but studies suggest that when people outgrow their food allergies, it is taking longer than was previously thought. Studies in recent years have noted factors that may lead to a lower likelihood of developing a food allergy, including the early introduction of common food allergens, having a sufficient vitamin D level, or having a higher maternal intake of peanut early in pregnancy. Given a recent report that sensitization to common food allergens did not increase from the late 1980s/early 1990s to the mid-2000s, further studies will need to examine if the rise in food allergy prevalence is due to a change in the relationship between sensitization and clinical allergy or changes in the recognition and diagnosis of food allergy.

Eosinophilic Esophagitis From an Allergy Perspective: How to Optimally Pursue Allergy Testing & Dietary Modification in the Adult Population.

Eosinophilic esophagitis (EoE) is a clinicopathologic condition characterized by symptoms of esophageal dysfunction and eosinophil-predominant inflammation. In adults, the three most common treatment options are swallowed steroids, elimination diets, and periodic esophageal dilations. Many different elimination diets have been studied in adults, including elemental diets, allergy testing-directed diets, and empiric elimination diets. This article will review the existing data on these dietary therapies and will propose an approach to dietary management in adult EoE.

Agreement between questionnaire report of allergy-related outcomes in school-age children and objective measures of atopy: the Saskatchewan rural health study.

BACKGROUND AND OBJECTIVES: In population-based studies, questionnaires remain the most efficient tool to assess the presence of allergy and atopic conditions, but the quality of the information obtained needs to be validated. We sought to evaluate the agreement and predictive values of a questionnaire to assess atopy in rural children, an understudied population with regard to atopy and allergic disease. METHODS: A total of 480 schoolchildren (grades 1-8) from rural Saskatchewan completed a questionnaire report of allergy and atopic outcomes and participated in skin prick testing (SPT). SPT for 6 common allergens (local grasses, wheat dust, cat dander, house dust mite mixed, Alternaria, and Cladosporium) was completed. Subjects with at least one positive SPT (≥ 3 mm) compared to the negative control were considered to be atopic. We considered per cent concordance, Kappa, sensitivity, specificity, and the positive predictive value and negative predictive value (NPV, PPV) of reported allergies or allergic conditions in comparison with SPT as the gold standard. RESULTS: We found that 25.0% of children reported a history of any allergy and 19.4% were atopic based on SPT. The agreement between questionnaire report of allergic triggers and atopy measured by SPT was high (83.0-89.5%). The agreement between atopy and report of allergic conditions ranged from 67.1% to 79.6%. Individual allergic conditions demonstrated high specificity but low sensitivity. The questionnaire report of any allergy had a low PPV in detecting atopy (47.3%) and high NPV (86.3%). The PPV of reported allergic conditions was low (24.8-43.9%), but the NPV was again high (82.0-82.9%). CONCLUSIONS: We found that the standardized questionnaire report of allergy and atopic conditions was shown not to efficiently and reliably predict atopy. However, given the good specificity and the NPV, the questionnaire may be an efficient tool for epidemiological studies that involve the differential inclusion of subjects without atopy.

Pragmatic randomized controlled trial of a structured allergy intervention for adults with asthma and rhinitis in general practice.

BACKGROUND: It is widely believed that in patients with allergic rhinitis and asthma, avoidance of specific triggers can help improve symptom control and reduce need for medication. Whilst most patients with asthma or rhinitis are sensitized to airborne allergens, primary care diagnostic and management decisions are often made without either obtaining a detailed history of the patient's allergic triggers or performing skin prick tests. Thus, management decisions are empirical and allergen avoidance advice is either not given or, if given, not tailored to the patient's sensitivities. METHOD: To ascertain whether allergy assessment and tailored advice in general practice for patients with asthma and rhinitis enhance well-being, we conducted a pragmatic, open, randomized controlled trial of allergy intervention (structured allergy history and skin prick testing and appropriate advice on allergy avoidance) versus usual care in adult patients with a working diagnosis of asthma and/or rhino-conjunctivitis. Outcomes were assessed after 12 months by an observer who was blinded to allocation. The main outcome measures were asthma and rhinitis symptoms, disease-specific health-related quality of life, generic quality of life and lung function. RESULTS: There were no significant differences in baseline demographics or disease characteristics between patients assigned to immediate or delayed skin prick testing. No significant differences were observed between groups for any measures of symptoms, quality of life or lung function at 12 months (all P > 0.05). CONCLUSION: Amongst adults with known asthma and/or rhinitis in primary care, taking a structured allergy history with skin prick tests and giving tailored advice on allergy avoidance made no difference to their symptoms, quality of life or lung function as measured twelve months later.