Peanut allergy: Recurrence and its management

Background

Although peanut allergy may recur, the frequency with which this occurs is unknown.

Objective

The goals of this study were to determine the rate of peanut allergy recurrence, identify risk factors for recurrent peanut allergy, and develop specific recommendations for the treatment of patients with resolved peanut allergy.

Methods

Children who outgrew peanut allergy were evaluated with questionnaires, skin tests, and peanut-specific IgE levels. Patients were invited to undergo a double-blind, placebo-controlled food challenge (DBPCFC) unless the history of a possible recurrence reaction was so convincing that a challenge would be potentially dangerous.

Results

Sixty-eight patients were evaluated. Forty-seven patients continued to tolerate peanut, of whom 34 ingested concentrated peanut products at least once per month and 13 ate peanut infrequently or in limited amounts but passed a DBPCFC. The status of 18 patients was indeterminate because they ate peanut infrequently or in limited amounts and declined to have a DBPCFC. After excluding 12 patients originally diagnosed with peanut allergy based solely on a positive skin prick test or peanut-specific IgE level, 3 of 15 patients who consumed peanut infrequently or in limited amounts had recurrences, compared with no recurrences in the 23 patients who ate peanut frequently (P=.025). The recurrence rate was 7.9 (95% CI, 1.7% to 21.4%).

Conclusion

Children who outgrow peanut allergy are at risk for recurrence, and this risk is significantly higher for patients who continue largely to avoid peanut after resolution of their allergy. On the basis of these findings, we now recommend that patients eat peanut frequently and carry epinephrine indefinitely until they have demonstrated ongoing peanut tolerance.

Key words: Peanut allergy, recurrence, food challenge, RAST, food hypersensitivity

Abbreviations used: DBPCFC, Double-blind, placebo-controlled food challenge, FEIA, Fluorescent-enzyme immunoassay, kU_A/L, Kilounits of antibody per liter, PN-IgE, Peanut-specific IgE, SPT, Skin prick test