To date, it is not possible to predict the severity of allergic reactions to food in the individual patient. The allergists can predict the likelihood of an allergic reaction from the size of the skin prick test or the level of the sIgE, but not the severity of the reaction. Data from children who had reactions to peanut during 126 double-blind, placebo-controlled food challenges (DBPCFCs) at the Swedish University Medical Center Groningen were analyzed (8 years).
Risk factors for reactions to lower doses included:
- age older than 10 years, hazard ratio 1.89
- specific IgE level above the lowest tertile (≥5.6 kU/L), hazard ratio 2
- absence of atopic dermatitis. Children without atopic dermatitis had more than twice the risk of reacting to a specific dose of peanut than did children with atopic dermatitis. Editor's note: this was an unexpected finding and the authors sounded surprised too in the discussion of the article. As usual, more studies are needed before a final conclusion can be made.
Greater clinical sensitivity in DBPCFCs to peanut was 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.
8 foods cause 90% of food allergies (TEMPS WFS) (click to enlarge the image). The likelihood of a negative oral food challenge is shown in relation to the respective values of skin prick test (SPT) and serum IgE (sIgE):
References:
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. Tjitske van der Zee et al. JACI, 2011.
Image source: Roasted peanuts as snack food, Wikipedia, public domain.
