Cross-allergenicity in the legume botanical family in children with food hypersensitivity

Abstract

Sixty-nine patients with one or more positive prick skin tests to legumes (peanut, soybean, green bean, pea, and lima bean) were evaluated for food hypersensitivity with in-hospital oral food challenges. Of the 280 prick skin tests to legumes performed, 130 were positive. Forty-three positive food challenges occurred in 41 patients. The prevalence of legume allergy was not statistically different in those patients (N = 36) with two or more positive legume prick skin test (64% positive) compared to those patients (N = 33) with only one positive legume prick skin test (55% positive; p greater than 0.10). Even in this selected patient population, only two patients had symptomatic hypersensitivity to two legumes. Among patients with a positive prick skin test to peanut (N = 60), the mean wheal size was larger in patients with a positive versus a negative oral food challenge to peanut (p less than 0.001). Results of oral food challenges demonstrate that clinically important cross-reactivity to legumes in children is very rare. Clinical hypersensitivity to one legume does not warrant dietary elimination of all legumes. Results of prick skin tests should not be used to determine prolonged food restriction diets.