The eliciting dose of peanut in double-blind, placebo-controlled food challenges decreases with increasing age and specific IgE level in children and young adults

Abstract

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. 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. 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. 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. 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.