Hypersensitivities to sesame and other common edible seeds

Several seeds have been increasingly incorporated in various food items, with consequent risk of hypersensitivity reactions that are often severe. Identification of the specific seed as the culprit is often not explored or is difficult to verify. In this article, we reviewed the English literature from January 1930 to March 2016 using PubMed and Google Scholar searching for publications relevant to hypersensitivity to common edible seeds, namely sesame, sunflower seed, poppy seed, pumpkin seed, flaxseed, and mustard seed. Considering the worldwide consumption of those seeds, the number of published articles on the subject was relatively small and was mainly as case reports rather than large series. Allergy to sesame was more reported than to other seeds, with an estimated prevalence of 0.1–0.2%. In this review, we summarize the information relevant to each of the six seeds and their oils regarding the manifestations, routes of exposure, identified major allergens, and cross‐reactivity with other seeds or other foods. We also addressed the important role of a thorough history taking in suspecting seed allergy, the limited reliability of routine diagnostic procedures, and the importance of verification by appropriate challenge tests. At present, management is basically dietary avoidance and the use of symptomatic medications that may include epinephrine auto‐injectors. We did not encounter any well‐designed studies on immunotherapy for seed allergy, but it is hoped that such a gap be filled by the development of safe effective protocols in the near future.     

Interpreting IgE sensitization tests in food allergy

Food allergies are increasing in prevalence, and with it, IgE testing to foods is becoming more commonplace. Food-specific IgE tests, including serum assays and prick skin tests, are sensitive for detecting the presence of food-specific IgE (sensitization), but specificity for predicting clinical allergy is limited. Therefore, positive tests are generally not, in isolation, diagnostic of clinical disease. However, rationale test selection and interpretation, based on clinical history and understanding of food allergy epidemiology and pathophysiology, makes these tests invaluable. Additionally, there exist highly predictive test cutoff values for common allergens in atopic children. Newer testing methodologies, such as component resolved diagnostics, are promising for increasing the utility of testing. This review highlights the use of IgE serum tests in the diagnosis of food allergy.     

Hypersensitivity reactions from inhalation of milk proteins

We describe the case of a young man with IgE-mediated hyper sensitivity to milk, casein, and lactoglobulin, who went into respiratory crisis every time he milked his sheep.     

A prospective study of cow milk allergy in Danish infants during the first 3 years of life

A cohort of 1749 newborns from the municipality of Odense born during 1985 at the University Hospital were followed prospectively for the development of IgE-mediated and non-IgE-mediated cow milk allergy (CMA) during their first year. The diagnosis of CMA was based on the results of strict elimination/milk challenge procedures in a hospital setting, and continued clinical sensitivity to cow milk (CM) was assessed by rechallenging every 6-12 months until the age of 3 years. Further, in infants with CMA, the clinical course of adverse reactions to other foods and the development of allergy to inhalant allergens by 3 years were investigated. Of 117 (6.7%) with symptoms suggestive of CMA, the diagnosis of CMA was proven in 39 infants (2.2%). 64% showed cutaneous symptoms, 59% gastrointestinal symptoms, and 33% had respiratory symptoms. 92% had two or more symptoms and 72% symptoms from greater than or equal to 2 organ systems. Based on a positive skin prick test (greater than or equal to 2+) and/or AL-RAST class greater than or equal to 2 to CM 16 infants at the time of diagnosis, and at reinvestigation at 1 year, a further five infants giving a total of 21, were classified as having IgE-mediated CMA, 19 infants showed "immediate reactions" to CM (within 1 h after intake of 2.3 g milk protein) and 20 infants were "late reactors". No significant correlation between IgE-mediated CMA and "immediate reactions" to CM was demonstrated. The overall prognosis of CMA was good with a total recovery of 22/39 (56%) at 1 year, 30/39 (77%) at 2 years, and 34/39 (87%) at 3 years. Adverse reactions to other foods, particularly egg, citrus, tomato, developed in a total of 21/39 (54%) with the maximum point prevalence of 15/39 (38%) at 18 months, and 9/39 (23%) were still intolerant to other foods at 36 months. Inhalant allergy before 3 years developed in 11/39 (28%), particularly against dog and cat to which the infants had been exposed. Infants with CMA and early IgE sensitization to CM had an increased risk of persisting CMA (24%), development of persistent adverse reactions to other foods (38%), particularly egg white (29%), and finally, inhalant allergy (48%) before 3 years of age.     

Allergic sensitization and clinical reactions to latex, food and pollen in adult patients

BACKGROUND: Many latex-allergic patients are sensitized to one or more foods. Patients allergic to tree and/or grass pollens are also often sensitized to plant-derived foods. Atopy, defined in most studies as sensitivity to an aeroallergen, is a risk factor for latex allergy. The relative importance of pollen sensitivity, a sign of atopy, as a risk factor for food allergy in latex-allergic patients has not, however, been examined. OBJECTIVE: To investigate the relationship between pollen sensitivity and sensitivity to food in latex-allergic patients. METHODS: Forty-four latex-allergic patients (Groups 1 and 2), 24 of whom were also allergic to tree and/or grass pollen (Group 1) and 25 pollinosis patients who were not allergic to latex (Group 3) were studied. We obtained a history of reactions to food and skin tested them with 12 fresh-frozen fruits. RESULTS: All 12 foods induced a skin test reaction in at least one patient in each of the three Groups. There were, however, twice as many positive skin test reactions to food in patients with pollinosis, whether or not they were allergic to latex, as there were in patients allergic to latex but not to pollen. Latex-allergic patients were most likely to have a positive skin test and a history of a reaction to avocado or banana whereas patients with pollinosis only were most likely to have a positive skin test and a history of a reaction to apple, peach or celery. CONCLUSIONS: These results suggest that concomitant allergy to pollen is an important risk factor in determining which plant-derived foods sensitize latex-allergic patients.     

The changing face of food hypersensitivity in an Asian community

BACKGROUND: Food allergy seems to be increasing in Asia as well as world-wide. Our aim was to characterize food protein sensitization patterns in a population of Asian children with possible food allergy. METHODS: Children presenting to our allergy clinic over 3 years with symptomatic allergic disease and at least one specific food allergen sensitization documented on skin prick testing were included in the analysis. RESULTS: Two hundred and twenty-seven patients fulfilled inclusion criteria. Ninety (40%) of the positive skin tests were positive to egg, 87 (39%) to shellfish, 62 (27.3%) to peanut, 30 (13.2%) to fish, 27 (11.8%) to cow's milk, 21 (9.3%) to sesame, 13 (3.7%) to wheat and eight (3.2%) to soy. Peanut sensitization was the third most common sensitizing allergen, and seen mostly in young atopic children with multiple food hypersensitivities and a family history of atopic dermatitis. The median reported age of first exposure to fish and shellfish was 6 and 12 months, respectively. The mean age at presentation of children with shellfish hypersensitivity was at 6.7 years of age. The likelihood of shellfish sensitization was increased in children with concomitant sensitization to cockroaches. CONCLUSIONS: In contrast to previously reported low peanut allergy rates in Asia, in our review, peanut sensitization is present in 27% (62/227) of food-allergic children, mostly in patients with multiple food protein sensitizations. Temporal patterns of first exposure of infants to fish and shellfish are unique to the Asian diet. Shellfish are a major sensitizing food source in Asian children, especially in allergic rhinitis patients sensitized to cockroaches.     

How long does the effect of birch pollen injection SIT on apple allergy last?

Background: Recent studies showed that injection specific immunotherapy (SIT) with birch pollen extract greatly reduces or cures the associated apple allergy in a large proportion of birch pollen-allergic patients. However, the long-term efficacy of SIT for apple allergy has not been assessed. Objective: To evaluate the duration of the effect of injection SIT with birch pollen extract on apple allergy in birch pollen-allergic patients. Methods: Thirty birch pollen-allergic patients showing both the clinical disappearance of apple allergy and a negative SPT with fresh apple at the end of their injection SIT course were followed-up at 12-month intervals from 6 months after SIT was stopped. Apple tolerance as well as SPT was assessed on all occasions. Fifty-seven birch pollen-allergic subjects without apple allergy and not submitted to SIT regularly followed-up for the onset of oral allergy syndrome (OAS) were used as controls. Results: The overall prevalence of OAS after 30 months of follow-up did not differ between patients and controls. Although most patients became re-sensitized to apple by SPT over time, >50% of them were still able to tolerate eating the fruit at the 30-month follow-up visit. Conclusion: Although most patients show a ‘natural’, gradual propensity to apple re-sensitization (a consequence of prolonged and repeated inhalation of birch pollen responsible for primary sensitization?), the clinical effects of injection SIT on food allergy seem rather long lasting.     

Allergy to honey: relation to pollen and honey bee allergy

To identify the allergenic components of honey we studied 22 patients with a history of systemic allergic symptoms following honey ingestion. The group of honey-allergic patients was compared with three control groups: 10 subjects sensitized to artemisia, 10 with honey bee venom allergy and 10 without a history of atopy or bee sting reactions. The allergological tests included skin tests and RAST with three different kinds of Swiss honey (dandelion, forest and rape), pollen of compositae species, celery tuber, extract of bee pharyngeal glands, honey bee venom and bee whole body extract. The results show that 3/4 of honey-allergics are sensitive to dandelion honey and 13 of 22 also to compositae pollen. Nine of the honey allergic patients were sensitized to honey bee venom, 3 also to bee pharyngeal glands and to bee whole body extract. Analysis of diagnostic tests and RAST inhibition studies suggest that besides compositae pollen other allergens, most likely of bee origin are important. In honey allergics primary sensitization may be due either to the honey itself, to airborne compositae pollen or even to cross-reacting bee venom components.     

Allergy to goat and sheep cheese with good tolerance to cow cheese

BACKGROUND: We report on a patient who experienced allergic reactions after eating goat cheese and after touching goat and sheep cheese, but not after consuming cow's milk dairy products. OBJECTIVE: To assess the allergenicity and IgE-binding capacity of the caseins from the three different species. METHODS: Skin prick tests were carried out using whole milk and caseins from three different species (goat, sheep and cow), and whey fractions of cow's milk. Total serum IgE and specific IgE to cow's milk proteins were measured by CAP system and specific IgE against caseins and whole milk were determined by ELISA technique. To evaluate allergenic cross-reactivity, inhibition of the IgE ELISA activity to goat's milk and goat casein was tested for the three caseins. SDS-PAGE and immunoblotting was used to determine IgE binding bands in caseins. RESULTS: Skin tests were positive to sheep and goat's milk, sheep and goat casein, as well as to sheep and goat cheese. Total serum IgE was 66 kU/L and IgE determinations by CAP were negative. IgE ELISA against the caseins from goat and sheep was strongly positive, whereas it was negative to cow casein. ELISA inhibition assays revealed a high degree of cross-reactivity between goat casein and sheep casein. Immunoblotting showed three IgE-binding bands in goat casein at 31, 27 and 22 kDa, which may correspond to alpha-, beta- and gamma-caseins. A band at about 31 kDa was observed in sheep casein and another band at 34 kDa was recognized in cow casein. CONCLUSION: This patient developed allergy to goat and sheep cheese with good tolerance to cow's milk. We identified goat casein as the main allergen causing sensitization in this patient as demonstrated by in vivo and in vitro tests. A high degree of cross-reactivity between goat and sheep casein was observed.     

The SAFE project: 'plant food allergies: field to table strategies for reducing their incidence in Europe' an EC-funded study

The true prevalence of food allergy as an IgE mediated reaction is still under discussion. Using apple as a model allergen source a multidisciplinary consortium worked together at developing various strategies for reducing the incidence of fruit allergies in an EC-funded project. Patient allergen profiles were established using in vitro and in vivo tests with respect to geographic area and mild or severe symptoms. Apple allergens (Mal d 1-Mal d 4) were characterised, variants identified, cloned and sequenced. These individual allergens were used to increase the sensitivity and specificity of diagnosis. Furthermore, they provided better prognosis of disease severity. RT-PCR and ELISA were developed for determining the allergen specific mRNA and expressed allergenic protein in a large number of apple cultivars. Similarly, changes in allergen characteristics from harvest through storage to processing and the impact of agronomic practices were investigated. Allergen genes were mapped on a molecular linkage map of apple. The biological function of Mal d 1 was studied using the RNA interference strategy. Finally, consumer attitudes in Northern, Central and Southern Europe were gauged on the acceptability of low allergen cultivars or a GMO and its impact on product quality.