Prevalence and cumulative incidence of food hyper-sensitivity in the first 10 years of life

Background - Prevalence, incidence and natural history of food hypersensitivity (FHS) and its trends in an unselected cohort of older children are unclear.Methods - A birth cohort born on the Isle of Wight (UK) between 2001 and 2002 was followed up prospectively. Children were clinically examined and skin prick tested at set times and invited for food challenges when indicated. At 10 years of age, children were also invited for a blood test.Results - A total of 969 children were recruited at 12 weeks of pregnancy, and 92.9%, 88.5%, 91.6% and 85.3% were assessed at 1, 2, 3 and 10 years. Prevalence of sensitization to any allergen over 10 years was 186 of 969 (19.2%; 95% CI: 16.84–21.8) and 108 of 969 (11.2%; 95% CI: 9.31–13.29) children were sensitized to at least one predefined food allergen. Excluding wheat (due to cross-reactivity with pollen), 40 of 969 (4.1%; 95% CI: 3.19–5.32) children were sensitized to a predefined food allergen. Using food challenges and/or a good clinical history, the cumulative incidence of food hypersensitivity (FHS) in the first decade of life was 64 of 947 (6.8%, 95% CI: 5.2–8.4), while the prevalence of FHS at 10 years was 30 of 827 (3.6%, 95% CI: 2.54–5.15). The vast majority, 25 of 827 (3.0%, 95% CI: 1.8–4.2), suffered from IgE-mediated food allergy, while 5 of 827 (0.6%, 95% CI: 0.07–1.3) had non-IgE-mediated food allergy/food intolerance.Conclusions - By the age of 10 years, 6.8% of children suffered from FHS based on food challenges and a good clinical history. There was a large discrepancy between reported and diagnosed FHS

Very low prevalence of IgE mediated wheat allergy and high levels of cross-sensitisation between grass and wheat in a UK birth cohort

BackgroundPatients often report adverse reactions to wheat. Interpretation of sensitization to wheat pollen and flour with/without sensitization to grass pollen is a clinical problem.AimWe set out to determine the prevalence of wheat allergy in a birth cohort (10/11 year olds) and investigate the usefulness of performing skin prick tests (SPT), specific IgE tests and component resolved diagnostics to wheat pollen and flour.MethodsThe Food Allergy and Intolerance Research (FAIR) birth cohort included babies born on the Isle of Wight (UK) between September 2001–August 2002 (n = 969). Children were followed up at 1, 2, 3 and 10/11 years. 588 children had SPTs to wheat pollen and grass during the 10 year follow-up. 294 children underwent further SPT to wheat flour and 246 had specific IgE testing to wheat and grass.ResultsEight children underwent oral food challenges (OFC). We diagnosed 0.48 % (4/827; 95 % CI 0–1 %) children with wheat allergy based on OFC. 16.3 % (96/588) were sensitized to grass pollen, 13.4 % (79/588) to wheat pollen; 78 % (75/96) sensitized to both. Only one child was sensitized to wheat flour and wheat pollen, but not grass pollen. For specific IgE, 15.0 % (37/246) and 36.2 % (89/246) were sensitized to wheat and grass pollen, with 40.5 % (36/89) sensitized to both. Of the 37 children sensitized to wheat, 3 (8.1 %) were sensitized to omega 5 gliadin, 1 (2.7 %) to wheat lipid transfer protein and 1 to wheat gliadin.ConclusionClinicians should be aware of the high level of cross-sensitization when performing tests to wheat and grass pollen i.e. sensitisation to wheat specific IgE and wheat pollen SPT should be assessed in the presence of grass pollen SPT and/or specific IgE

Teaching Writing: a situated dynamic

publication-status: Publishedtypes: ArticleThe paper is theoretically grounded in Cultural Historical Activity Theory (CHAT) which holds that human development is founded within participation in social and cultural practices. In particular, the teaching of literacy is shaped not only by the curriculum as designated by policy makers and the institution in which it is located but also by the individuals’ understanding of what literacy and learning involves and how they act to achieve their goals. The paper explores data from a project that investigated the relationship between classroom talk and the teaching of writing in six early years classrooms. Participants’ own understandings of teaching and learning need to be taken into account by researchers and policy makers. CHAT has been used to explore the dynamic relationship between activity at societal, institutional and individual levels. It is argued that researchers and policy makers need to take account of the wider socio-cultural context in planning and evaluating curriculum development initiatives

The diagnosis of Brazil nut allergy using history, skin prick tests, serum-specific immunoglobulin E and food challenges

BACKGROUND: Allergy to Brazil nut is a relatively common nut allergy and can be fatal. However, the evidence is lacking regarding the best approach to its diagnosis. OBJECTIVE: We sought to determine the relative merits of history, skin prick testing, measurement of serum-specific IgE and challenge in the diagnosis of Brazil nut allergy. METHODS: Fifty-six children and adults with a history of an allergic reaction to Brazil nut or evidence of sensitization were investigated by questionnaire (n=56), skin prick tests (SPTs) (n=53), measurement of serum-specific IgE to Brazil nut (n=54) and double-blind, placebo-controlled labial, and if necessary oral, challenges (n=19). RESULTS: Brazil nut allergy occurred in highly atopic individuals of any age with a strong family history of atopy. In 24 of 56 (43%), the history of an immediate reaction was sufficient to make a diagnosis with confidence and an oral challenge was considered unsafe. Of the 19 subjects undertaking the 'gold standard' test of a double-blind, placebo-controlled, food challenge, all six subjects with a SPT of at least 6 mm had a positive challenge and all three subjects with a SPT of 0 mm had a negative challenge. In the remaining 10 (53%) subjects, where SPT was between 1 and 5 mm and serum-specific IgE was less than 3.5 kU/L, an oral challenge was performed resulting in three positive and seven negative challenges. CONCLUSION: A combination of history, SPT and serum-specific IgE was adequate in achieving a diagnosis in the majority (77%) patients with suspected Brazil nut allergy. However, a doubtful history with SPT between 1 and 5 mm, or a serum-specific IgE less than 3.5 kU/L may require an oral challenge to help determine the risk of a Brazil nut allergic reaction