In this issue

We publish the final manuscript in the Food Allergy educational series. This is on the diagnosis of immunoglobulin E-mediated food allergy and should prove very useful to all in practice, outlining how predictive values can be used in creating probability estimates for the presence or absence of a specific allergy. This provides the information required to judge whether an oral food challenge is required or not. This is followed by four questionnaire-based studies on various aspects of food hypersensitivity and food allergy. Clearly, the results must be cautiously interpreted as iterated within our educational series paper. However, where large numbers have been surveyed, it is certainly possible to derive information of value and interest. A large study from the Isle of Wight has issued a questionnaire to the pregnancy cohort to elicit information about dietary practices up to the infant s third birthday to establish what factors are associated with rigorously diagnosed food allergy and hypersensitivity. While maternal diet during pregnancy and breastfeeding duration appeared to have no influence on sensitization to foods, weaning age did have some impact. This has been a subject of discussion in our pages previously (1). The confusing and contradictory data accumulating on this topic suggests that at the moment, there is insufficient evidence in the literature to make any recommendations on weaning strategies and more research is certainly required as suggested in our recent expert group publication from the Section of Paediatrics of the European Academy of Allergology and Clinical Immunology (2). The second study from Finland identifies, based on a questionnaire survey, that a third of all infants have food-associated symptoms, a fifth have had a modification of their diet in removing at least one food item suggesting that up to 50% of children have had at least one food eliminated from their diet. This must be contrasted against physician diagnosed food allergy, which was detected in 9% only. This presents an even grimmer picture than that highlighted in a previous study of perceived vs. real food allergy in a Danish study (3). The other two questionnaire studies focus on parent-reported reactions to individual foods, one from Hong Kong and the other Japan. In Hong Kong, the discrepancy between parentreported and doctor-diagnosed adverse reactions to foods is very much smaller than has appeared from European studies. The league table of foods is a little different with shellfish figuring more prominently than egg, peanut or milk. The Japanese study focused on associations between reported sensitivity to more than one food. Most of the combinations were predictable on the basis of taxonomy although others were less easy to explain such as milk and wheat or chicken and beef. Does pet-keeping protect or enhance the development of allergic disease? The subject becomes ever more confusing. Our current article from Germany suggests that cat keeping promotes atopic disease and specifically associated with cat sensitization. Maybe this is consistent with previous papers from Finland (4) and from Bulgaria (5). The balance of evidence seems to be shifting away from a protective effect of exposure to pets with ever more recent studies showing positive associations between early pet exposure and risks particularly of developing asthma (6). The concept of the allergic march has undergone significant revision as the genetic basis of the separate atopic conditions, such as asthma and eczema, has been elucidated. Yet another publication from the highly successful Early Treatment of the Atopic Child (ETAC) study has shown that in infants with eczema, filaggrin polymorphisms are strongly associated with the subsequent development of asthma. Is this allergic sensitization to inhalant allergens occurring through an impaired skin barrier? This would reinforce the concept of an allergic march. As outlined in the editorial, there are some interesting associations between obesity and asthma. A study from the USA suggests a gender-specific association between high body mass index and asthma morbidity within an Pediatr Allergy Immunol 2009: 20: 307–308