Lupin allergy: a hidden killer in the home.

This review addresses the problem of lupin sensitization in the home environment. We summarize the data currently available on allergy to lupin, which has become, in recent years, a hidden killer in our homes. Since 2006, when lupin was included in European regulations as a food whose presence must be declared, the situation may have changed. Nevertheless, we must take into account the possibility of undeclared allergenic ingredients or the presence of 'hidden' allergens, given that contamination during food production processes may be a great risk for sensitized individuals. Furthermore, the United States, Japan, Australia and New Zealand still do not include lupin among the ingredients that must be listed on foodstuff labelling. Our responsibility is to educate the public so that they are aware of the danger and look for lupin in the labels of products that run the risk of containing it. Lupin allergy can manifest itself in isolation or in parallel to peanut allergy. Identification of the proteins causing possible cross-reactivity is complicated, and new structural studies are needed. To date, it has not been possible to clearly identify the allergens responsible for isolated lupin sensitization in relation to parallel and/or cross-sensitization between lupin and peanut. Most of the allergenic proteins of lupin are α- and β-conglutins, with a lesser presence of γ- and δ-conglutins. A β-conglutin corresponding to Lup an 1, with a sequence similar to Ara h 1, has been identified as a major allergen of lupin in patients with allergy following lupin ingestion.