In this issue

The predominant referrals to my allergy clinic in recent years have been children with putative adverse reactions to foods. Many of the children have already had consultations with other paediatricians and sometimes allergists. It is quite clear from the background information supplied by patients and their families that clinicians ®nd diagnosis and management of such problems enormously dif®cult. Thus I hope that readers will ®nd Scott Sicherer's very practical review of the diagnostic approach to such problems useful. He emphasizes the fundamental role of oral food challenge in managing food-allergic patients. Contrary to popular belief, this is not just a research investigative tool but is fundamental to the effective management of patients. There should be no embarrassment in reiterating the message given by Scott Sicherer to all our colleagues. However, of course, challenges must always be performed in an appropriate setting as emphasized in the review. It is incumbent on all allergy services to be able to provide such facilities The T-helper 1/T-helper 2 (Th-1/Th-2) paradigm has very rapidly become established dogma in relation to atopic disease. Successive papers have shown strong associations between Th2-biased responses in atopic dermatitis, asthma and allergic rhinitis. However, intriguing apparent inconsistencies in this paradigm have been highlighted. Thus, for instance, several recent studies have identi®ed an increase in interferon-c (IFN-c) production (a Th-1 cytokine) in bronchoalveolar lavage cells from asthmatics (1, 2). Dr Blanco-Quiros and colleagues have shown that the Th-2 paradigm holds true in pollen-sensitized children with rhinoconjunctivitis, with or without asthma. However, children with food sensitivity producing a range of manifestations, including asthma, atopic dermatitis and gastrointestinal symptoms, do not follow the paradigm in having increased serum interleukin-12 (IL-12) (an IFN-c inducer) and therefore a Th-1 cytokine with normal levels of soluble CD30, which has been preferentially associated with Th-2 responses. What is not clear from the description of the patients is whether the response to food challenge was immediate or delayed or both. If delayed, then it is perhaps not surprising that the immunological characteristics of the sensitivity are somewhat different to that of pollen allergy, which is so clearly an immunoglobulin Eassociated type-1 hypersensitivity. Much has yet to be delineated about the immunological basis of adverse reactions to food. A large number of studies have now identi®ed that the Th-1/Th-2 paradigm may also be apparent before the development of overt allergic disease and can sometimes be apparent at birth in infants destined to develop allergic disease. Indeed, this has been the topic of many papers published in Pediatric Allergy and Immunology. Less attention, however, has been paid to the potential for an unbalanced neonatal immune response to affect susceptibility to bacterial colonization. However, this is addressed in a very important paper by the Bochum academic paediatric group. The same disequilibrium of IFN-c generation by CD45RO+ (memory Tcells) stimulated with staphylococcal enterotoxin was associated with subsequent nasal colonization by staphylococci, as has been seen in relation to allergen responses and subsequent allergic disease. It will be most interesting to hear longer term follow-up on these patients, particularly in relation to the development of atopic dermatitis. We are taken to task by Dr Miceli Sopo over methodological issues in relation to studying cord blood and peripheral blood mononuclear cell responses to allergen in vitro. The group highlight discrepancies in successive studies and suggest that more rigorous standardization of methodology is required. If T-cell culture is to become more of a science than an art, there will be a need to establish an international consensus on standardization of technique. There has been considerable interest in attempting to delineate the mechanisms of Tlymphocyte migration into target organs as allergic disease evolves. Until now, most studies have postulated a role for the cutaneous lymphocyte-associated antigen in relation to migration into skin in atopic dermatitis. The Melbourne immunology group suggest that, while this molecule might have some role in skin disease, there must be other factors that are likely to be more important in determining migration of T cells. Their paper also emphasizes the effect of age on expression of the antigen. It again emphasizes the importance of studying very Pediatr Allergy Immunol 1999: 10: 224±225