Scientific Study

Background: Several risk factors for severe anaphylactic reactions to food in daily life are known. However; to date; it is not possible to predict the severity of allergic reactions to food in the individual patient with accuracy. Some studies show that a history of severe reactions is associated with a lower eliciting dose in double-blind; placebo-controlled food challenges (DBPCFCs). Therefore; in this study; the eliciting dose was used as a measure of clinical sensitivity. Objectives: To study whether risk factors for severe allergic reactions to food in daily life such as age; degree of sensitization; and coexistent atopic disease influence the eliciting dose in DBPCFCs in children allergic to peanut. Methods: Data from children who had clinical reactions to peanut during DBPCFCs at the University Medical Center Groningen (2001-2009) were analyzed. A Cox regression model was used to analyze the association of the determinants with the eliciting dose. Results: One hundred twenty-six positive DBPCFCs with peanut were analyzed. Age older than 10 years; a specific IgE level above the lowest tertile (=5.6 kU/L); and the absence of atopic dermatitis were associated with reactions to lower doses: respective hazard ratios 1.89 (95% CI; 1.28-2.81; P = .001); 2.03 (95% CI; 1.37-3.00; P < .0001); and 0.45 (95% CI; 0.29-0.71; P = .001) present versus absent. No significant associations with the eliciting dose were found for sex; the presence of asthma and rhinitis; and the severity of food reactions by history. Conclusions: Using the eliciting dose as a measure of clinical sensitivity; greater clinical sensitivity in DBPCFCs to peanut was found to be associated with increasing age; higher specific IgE level; and the absence of atopic dermatitis. This finding may explain why adolescents experience severe allergic reactions in daily life to peanut more often than do younger children.