Background: Evidence-based primary prevention of allergic conditions is important in view of their increasing prevalence in Western industrialized countries.
Methods: The Cochrane and Medline databases were searched for relevant scientific publications that appeared from February 2003 to May 2008. Articles in the reference lists of recent reviews were also considered, and experts were directly asked for their opinions. The retrieved publications were screened for relevance by evaluation of the title and abstract, and then by evaluation of the entire text. Each study chosen for inclusion was assigned an evidence grade as well as a grade for study quality relating to its potential for bias (low or high). The revised recommendations were then formally accepted by a consensus of representatives of medical specialist societies and other organizations, including a patient self-help group.
Results: The search initially yielded 4556 results out of which 217 articles (4 Cochrane reviews, 14 meta-analyses, 19 randomized clinical trials, 135 cohort studies, and 45 case-control studies) were chosen for inclusion and critical appraisal. No major changes ensued in the existing recommendations to avoid exposure to tobacco smoke, breast-feed for 4 months (or use hypoallergenic formulas), avoid a mould-promoting indoor climate, avoid exposure to furry pets (particularly cats), and vaccinate according to the current recommendations of the Standing Committee on Vaccination of the Robert Koch Institute (Ständige Impfkommission, STIKO). Neither the delayed introduction of solid food nor the avoidance of potent dietary allergens is recommended as a means of primary prevention. New recommendations were issued regarding fish consumption (by the mother while breastfeeding and nursing, and by the infant as solid food), avoidance of overweight, and reduction of exposure to air pollutants.
Conclusions: This updated guideline serves as an aid in giving patients current, evidence-based recommendations for allergy prevention.
Keywords: allergy; evidence-based medicine; guideline; prevention.