Lupin: a new hidden food allergen.

wo of the three patients described here were atopic and thus had an increased propensity to develop food allergy, although one of them had no previous food allergies and the third had no previous allergies at all. None was allergic to peanut. None had exercised after eating the implicated foods, and none reacted to normal bread, other wheat sources, or pea. Discussion IgE-mediated food allergy is an important cause of acute anaphylaxis 1 and anaphylaxis-related death. 2 The major allergenic foods are well known: peanuts and tree nuts (in people of all ages), milk and egg (mainly in children), and crustaceans and fish (mainly in adults). A variety of other foods are less commonly responsible for anaphylaxis. Peanut-allergic individuals are sometimes allergic to other foods from the legume family, such as soy. Lupin, another legume related to pea, peanut and soy, has been recognised in Europe as a cause of allergic reactions and anaphylaxis. 3-5 Lupin flour in food has been reported to produce urticaria and anaphylaxis, 3 and may also produce rhinitis and asthma in an occupational setting, through inhalation. 6,7 Moneret-Vautrin et al reported that 44% of children allergic to peanut showed positive skinprick responses to lupin, and 7 of 8 who were challenged reacted to lupin flour. 8 It seems that lupin allergy may arise by cross-reactivity in people who are already allergic to peanut, or de novo, by primary sensitisation, as in the cases reported here. Lupinus albus (of the genus Lupinus, which has about 500 members, including ornamentals) is the species most widely cultivated for food (Box 2). Dried lupini, prepared by boiling — a Lupin: a new hidden food allergen Clinical records Patient 1 A 42-year-old woman developed acute urticaria and angioedema, with throat tightness and cough, after a meal including a bread roll. A more severe anaphylactic reaction, including marked breathlessness requiring oxygen and adrenaline, followed ingestion of the same type of bread roll on another occasion. The only unusual ingredient in this type of bread roll is lupin bran. Skinprick tests with saline extracts of the raw lupin bran and the baked bread roll were strongly positive (Box 1). Tests for allergy to soy and peanut were negative. The patient's history included seasonal rhinitis with positive skin tests to aeroallergens, but no previous food allergy. She was advised to avoid products containing lupin, as far as possible. She decided not to carry …