Ruling out food allergy in pediatrics and preventing the "march" of the allergic child.

When a child presents with an allergic symptom, the general pediatrician needs to discriminate which patient has to be sent to the specialist for an allergologic evaluation. If referred, the child will undergo not only skin-prick test, but also more complex specialistic evaluations that we define here as "the march of allergic children." The objective of this article is to overview the clinical evidence about possible diagnostic interventions to avoid unuseful referrals of children reported with allergy from the general to the specialist level. Data sources include PubMed, using a search algorithm selecting for diagnostic studies of respiratory and food allergy in all children to August 2005. Also included are commentaries based on the authors' clinical experience in the allergy unit of a University Hospital in Italy. No study prospectively assessed the rule-out efficacy of clinical history, physical evaluation, and skin-prick test panels on the allergic disease. Three prospective studies on in vitro panels of specific IgE sensitization matched entry criteria. Diverse trial designs and diagnostic criteria precluded meta-analytic methods. The use of in vitro panels proved effective in ruling out the allergic condition in children. The screening efficacy of panels of food and respiratory skin-prick tests remains to be evaluated. With sensitivities and negative predictive values exceeding 90%, in vitro panels can inform the decisions of pediatricians in their capacity as gateway to specialist care. Avoiding the march of allergic children from the GPs to the secondary level is a more realistic goal than preventing the allergic march.