In vitro immunologic diagnosis of hypersensitivity to vegetables

Abstract

Acute reaction to food allergens is a fairly common problem that is often seen in the allergist's office, its incidence being specially high in childhood. Milk and eggs are the most common sensitizing foods, but usually the type of food allergens responsible for these reactions varies according to food habits in different countries. Legumes occupy an important role in the Spanish diet, being responsible for a large number of allergic reactions. It has been shown that legumes occupy the fourth place in importance among the food allergens, inducing hypersensitivity reactions in Spanish children. This article describes five patients with clinical features suggestive of being mediated by IgE antibodies specific for different legumes. In all the cases, disorders appeared immediately after the ingestion or even the inhalation of vapours from cooked legumes (lentil, bean or chick-pea). Clinical features consisted of: urticaria, angioedema, abdominal symptoms and rhinoconjunctivitis and/or asthma. The five patients required hospital emergency care on several occasions. Two patients suffered also from seasonal pollinosis with rhinoconjunctivitis and asthma. All the patients complained of these type of disorders with any legume, but lentil was found to induce the most severe reactions and it was therefore selected for this study. The presence of specific IgE antibodies was demonstrated in vivo in all the patients by means of skin prick-test. It was performed using a lentil extract prepared in our laboratory. Negative controls were also included. A reverse enzymeimmunoassay (REIA) revealed the presence of specific IgE antibodies in the sera of the five subjects.