The natural history of peanut allergy in young children and its association with serum peanut-specific IgE

Objectives: To observe the nature and frequency of adverse reactions caused by accidental peanut exposure in young children with clinical peanut hyper sensitivity and to determine the value of serum peanut-specific IgE levels during follow-up. Study design: Eighty-three children with clinical peanut hypersensitivity d iagnosed before their fourth birthdays were contacted yearly to track adver se peanut reactions. Serum peanut-specific IgE levels were determined in 51 of 83 subjects. Results: Fifty-eight percent (31/53) of subjects followed up for 5 years ex perienced adverse reactions from accidental peanut exposure, Regardless of the nature of their initial reaction, the majority with subsequent reaction s (52%, 31/60) experienced potentially life-threatening symptoms. The group with isolated skin symptoms (11/51, 22%) had lower serum peanut-specific I gE levels than the group with respiratory and/or gastrointestinal symptoms (40/51, 78%) (median: 1.25 kU(A)/L vs 11.65 kU(A)/L, P = .004, Wilcoxon ran k sums test). Despite this, there was no threshold level below which only s kin symptoms appeared to occur. Four selected subjects had negative double- blind placebo-controlled food challenge responses to peanuts during follow- up. Conclusions: The majority of children with clinical peanut hypersensitivity followed up for 5 years will have adverse reactions from accidental peanut exposure. Symptoms experienced during subsequent adverse peanut reactions may not be consistent with symptoms reported during initial reactions. Ther efore proper education regarding peanut avoidance land treatment of adverse reactions is necessary in all cases of clinical peanut hypersensitivity. Y oung children who are allergic to peanuts can lose clinical hypersensitivit y.