Allergy and eczema in context (and transition) (2004)

There is no agreement on the relevance of the early diagnosis of allergy in paediatric allergic eczema/dermatitis syndrome (AEDS). While the acceptance of a terminology (1) and classification system common to the major medical specialities concerned is growing, the care pathway that should look after children from their first symptoms of food allergy to established respiratory allergy remains somewhat lacking in definition. Prevention strategies and early treatment may thus be unduly delayed to the prejudice of the patient during her period of development (2,3). Recent insights have been gained into the immunopathology of AEDS (4). New diagnostic technologies have appeared. The demand for managed care and the need for integrated care pathways have grown (5). Allergists, dermatologists, pharmacologists, gastroenterologists and pulmonologists have begun to generate dynamic relationships between their disciplines to integrate the work of primary care paediatricians, referring physicians and hospital-based specialists into their speciality rationales. However, eczema remains a telling case against the division of labour in this field as a unique and complex manifestation of the atopic phenotype and as the forerunner of progressive but worsening disease. Observations in AEDS have overlapping layers: family history of allergic disease, elevated serum immunoglobulin E (IgE) levels in 80% of children, rhinitis progressing to asthma, disputed roles for clinical sensitization to food allergens (6), exacerbation/improvement of symptoms with allergen exposure/avoidance. The spectrum of presentations is wide, heterogeneous information is now beyond the remit of the single-organ specialist and the general practitioner on their own. Never before has the need for consensual diagnostic criteria in clinical practice and research settings been more acutely felt. A paradigm shift is in progress as practice parameters and clinical guidelines are being redrawn. The patient comes first and the most blatant denial of a small child's right to a prompt diagnosis and treatment is represented by the reluctance of many practitioners to perform skin or provocation tests. The fear is that the extent of lesions or the perceived risk of anaphylaxis will increase patients' risks or yields false negatives (7). Much depends on the ability of skin tests to predict future offending foods according to the nature of the food being tested and on the ability of food challenges to exclude false positives. However, research on generalizable diagnostic pathways is relatively scant. An integrated work-up of allergy in AEDS and of skin manifestations in food allergy is needed. A re-appraisal of the accuracies of the various tests (together with more population-based prevalence data) should be modelled into a decision analysis of when – and which − test to perform within the diagnostic process itself. In research settings knowledge of food allergy and of the prevalence of the various allergens in the paediatric (as opposed to referral) population would mean better planned preventive intervention, geared towards the introduction of solid foods, with benefits for both allergic and nonallergic children (7). Not all AEDS is the result of food-related factors and reverse causation relationships may even be found eventually. The syndrome has such a complex immune and nonimmune aetiopathology from genes to clinic that onset, severity, or staphylococcal infections, to cite but a few issues, can only be apprehended in a multidisciplinary, case-progress approach by medical practitioners and their patients. A fundamentally clinical question is who should preferentially manage the child with AEDS. Paediatric practice may be already altered by the advent of the novel and potent topical immunomodulators available today. A ‘clear skin, hence no allergy’ outlook has spread among first-tier caregivers. This is to the detriment of an integrated work-up methodology based on the hospital-based specialist. While not necessarily negative per se, this further division of the medical responsiveness to AEDS may delay the process of allergy diagnosis and thereby also elimination diets. Eventually it may hinder preventive measures against childhood asthma. With such issues at stake treatment guidelines and diagnostic criteria are in the process of being redrawn and it is in this context that the debate between all stakeholders should be viewed. Eczema may or may not kick off the whole process but food hypersensitivity increases eczema severity (6,8,9) − mainly (10) among younger children – and food allergen sensitization is thus a step towards inhalant allergy and allergic asthma. It would be logical to expect AEDS to belong entirely to this classical triad, but this is only part of the picture. A momentum is gathering speed towards a multidisciplinary approach to diagnosis, management and prevention. The understanding is that food allergy is cause for concern with the more severe and earlier forms of atopic disease. That restrictive diets exclusive of the most likely allergenizing offenders should remain a mainstay of therapy in AEDS has also emerged. As the studies in these Proceedings are witness, the way ahead lies in the direction of a rationale-based work-up of food allergy for patients with AEDS, with the upshot that consensual approaches to therapy will also emerge in the process. This publication would not have been possible without the contribution of Filippo Brandi PhD, Allegria Secretary General.